Ultrasound references and measurements

The most complete, fully referenced compilation online: normal values, color bands (normal / borderline / abnormal), classifications and built-in calculators — with sources cited in every block. Assistive; confirm with the literature and your clinical judgment.

Urinary tract / Kidneys

Brazil: CBR defines kidneys and bladder as the exam scope; ureters/adrenals are reported when abnormal, and post-void residual is added by indication or request. US/Europe: interpret PVR cautiously because thresholds vary across guidance.

Measurements and reference values

Measurement	Usual value	Note
Adult kidney — bipolar length	9–12 cm	varies with height, sex, age and body habitusconsensus normal: 9–12 cmborderline/context: 8–9 ou 12–13 cmlikely abnormal: <8 ou >13 cm
Length difference between kidneys	≤ 1,5 cm	larger difference suggests unilateral disease or anatomic variation to correlatenormal: ≤1,5 cmabnormal: >1,5 cm
Renal parenchyma — thickness	1,3–2,5 cm	less than 1.0 cm is compatible with relevant thinningpreserved: ≥1,3 cmborderline: 1,0–1,2 cmthinned: <1,0 cm
Renal cortex — thickness	7–15 mm	varies by technique; interpret with echogenicity and kidney sizepreserved: ≥10 mmtechnique/age zone: 7–9 mmmarked thinning: <7 mm
Bladder wall — full bladder	≤ 3 mm	3–5 mm depends on filling; >5 mm with a full bladder is suspiciousnormal full: ≤3 mmborderline/filling: 3–5 mmthickened: >5 mm
Bladder volume for evaluation	200–300 mL	partially full bladder improves wall and lesion assessment
Bladder volume calculation	comprimento × largura × profundidade × 0,52	some protocols use different coefficients depending on bladder shape
Post-void residual	<30 local; <50–100 consenso mL	local protocol marks >30 mL as abnormal; there is no single consensus threshold; measure soon after voidinglocal normal: <30 mLabnormal by local protocol: 30–49 mLnormal in some sources: 50–99 mLacceptable/borderline: 100–200 mLinadequate/retention: >200 mL

Classifications and calculators

Post-void residual — consensus reading

Range	Reading	Comment
< 30 mL	Strict local normal	Cutoff used by the local service protocol; above this, PVR may be described as increased/abnormal in the physician’s reporting style.
30–49 mL	Abnormal by local protocol	Range above the local 30 mL cutoff; still below the <50 mL cutoff used by Brazilian sources for non-neurogenic urinary incontinence.
50–99 mL	Divergent	Normal in some international references, but above the local and Brazilian conservative cutoffs.
100–200 mL	Acceptable in context	May occur in older adults or specific symptoms; correlate.
> 200 mL	Inadequate emptying	Suggests voiding dysfunction or obstruction, depending on context.
> 300 mL	Suggests retention	AUA uses persistent >300 mL as a volumetric definition of chronic retention.
> 400 mL	Urinary retention	Generally treated as urinary retention.

Use the calculator above with post-void volume in mL. Pre-void volume is optional and calculates residual percentage.

Source: Protocolo local / Ministério da Saúde BR 2020 / ICS teaching module / StatPearls PVR / AUA white paper

Hydronephrosis — ultrasound grading

Grade	Finding	Interpretation
Absent	Nondilated collecting system	Normal when there is no obstructive context.
Mild	Early calyceal/pelvic dilatation, papillae preserved	Real finding, but may depend on hydration, full bladder or variant.
Moderate	Rounded calyces and effaced papillae	Higher suspicion for obstruction; correlate with pain, ureter and ureteric jet.
Severe	Confluent calyces and thinned cortex (<1 cm)	Consensus important abnormality; look for obstructive cause.

Grading is partly subjective; differentiate from extrarenal pelvis and parapelvic cysts.

Source: StatPearls Urinary Tract Ultrasound / SFU concepts

Bosniak 2019 — renal cysts

Class	Description	Malig. risk	Note
I	Simple cyst: anechoic, thin wall and posterior enhancement	~0%	No follow-up when typical.
II	Few thin septa or fine calcification, no solid component	<1%	Generally benign.
IIF	More septa or mild thickening: needs follow-up	~5–10%	Gray zone; CT/MRI or contrast improves characterization.
III	Thick or irregular enhancing wall/septa	~50%	Indeterminate/suspicious.
IV	Enhancing solid component	~90–100%	High suspicion.

Bosniak was created for contrast CT/MRI. On noncontrast ultrasound, use as descriptive triage and recommend contrast imaging if complex.

Source: Bosniak v2019 (Radiology/RSNA) / StatPearls Urinary Tract Ultrasound

Abdomen (total / upper)

Brazil: CBR standardization defines total abdomen as liver, bile ducts, gallbladder, spleen, pancreas, kidneys, bladder, abdominal aorta, inferior vena cava and retroperitoneum in B-mode; pelvic organs and prostate are not included. Upper abdomen focuses on liver, gallbladder, bile ducts, pancreas, spleen and great vessels. US/Europe: use thresholds with clinical context, technique, age and SRU/EFSUMB/ACC-AHA guidance.

Measurements and reference values

Measurement	Usual value	Note
Liver — craniocaudal length at the midclavicular line	≤ 15 cm	15–16 cm is a technique/body-habitus zone; measure in the largest reproducible axisconsensus normal: ≤15 cmborderline: >15–16 cmlikely hepatomegaly: >16 cm
Spleen — adult long axis	≤ 12 cm	12–13 cm varies with height, sex and technique; above 13 cm is usually abnormalconsensus normal: ≤12 cmborderline/body habitus: >12–13 cmlikely splenomegaly: >13 cm
Common bile duct with gallbladder present	≤ 6–7 mm	age over 60 years and opioids may explain mild nonobstructive dilationstrict normal: ≤6 mmborderline/context: >6–7 mm ou idoso ≤8 mmlikely dilated: >7 mm sem contexto benigno
Common bile duct after cholecystectomy	≤ 8–10 mm	may increase over time after surgery; symptoms and bilirubin change managementpost-surgical normal: ≤8 mmaccepted by some sources: >8–10 mmrelevant dilation: >10 mm
Intrahepatic bile ducts	não visíveis / ≤ 1 mm	some references use >2 mm as intrahepatic dilatationnormal: não visíveis ou ≤1 mmtechnical zone: 1–2 mmdilatation: >2 mm
Gallbladder — fasting wall thickness	≤ 3 mm	pseudothickening occurs when the gallbladder is contracted or not fastingnormal: ≤3 mmborderline/context: >3–4 mmthickened: >4 mm
Incidental gallbladder polyp	< 6 baixo risco; ≥10–15 alto risco mm	SRU is less interventionist; European guidelines treat ≥10 mm more cautiouslylow risk: <6 mmfollow-up/risk: 6–9 mm ou 10–14 mm baixo risco SRUconsider surgery: ≥10 mm com risco ou ≥15 mm
Portal vein — resting diameter	6–13 mm	deep inspiration may reach 16 mm; interpret with spleen, collaterals and flow directionnormal: 6–13 mmborderline/context: >13–16 mmsuggestive dilatation: >16 mm
Portal vein — mean velocity	16–40 cm/s	should be hepatopetal; hepatofugal flow is abnormal regardless of the numbernormal: 16–40 cm/sborderline slow: 12–16 cm/slikely abnormal: <12, >40 ou hepatofugal
Main pancreatic duct	cabeça 3 / corpo 2 / cauda 1–1,5 mm	increases slightly with age; measure in the body near the head when possiblenormal in body: ≤2 mmhigh-normal/context: >2–3 mmlikely dilatation: >3 mm
Pancreas — approximate thickness	cabeça ~2; corpo/cauda 1–2 cm	isolated size is not robust; prioritize duct, contour and focal lesions
Abdominal aorta — maximum diameter	< 3 cm	3.0 cm defines aneurysm; usual repair threshold: ≥5.5 cm men and ≥5.0 cm womenusual diameter: <2,5 cmectasia: 2,5–2,9 cmaneurysm: ≥3,0 cm
Inferior vena cava — diameter and inspiratory collapse	< 2,1 cm + colapso >50%	criteria estimate right atrial pressure, not isolated volume statuslow/normal pressure: <2,1 cm + >50%indeterminate: achados discordanteslikely elevated pressure: >2,1 cm + <50%
Abdominal Doppler — minimum technique	fasting 4-6 h when possible; color and pulsed Doppler; angle up to 60 degrees; direction, velocity and waveform documented	Flow direction and vascular patency carry as much weight as the velocity number. Adjust gain, scale and wall filter so slow flow is not mistaken for thrombosis.adequate: direction + spectrum + angle documentedlimited: poor window, unreliable angle or nonfastingincomplete: vascular concern without pulsed Doppler or flow direction
Hepatic artery — resistive index	0,50–0,70	Outside transplant, interpret with context; in transplant and postoperative settings, extreme values, absent flow or tardus-parvus pattern are relevant.usual: 0,50–0,70borderline/contextual: 0,70–0,80 ou 0,45–0,50alert: >0,80, <0,45, ausência de fluxo ou tardus-parvus
Hepatic veins — spectral pattern	triphasic or phasic with the cardiac cycle	Loss of phasicity may occur with cirrhosis, congestion, technique or respiration; absent flow, thrombus or obstruction suggests hepatic venous disease.phasic: physiologic triphasic or biphasiccontextual monophasic: cirrhosis, technique or congestion without thrombusobstructive: no flow, thrombus, stenosis or venous collaterals
Transjugular intrahepatic portosystemic shunt — velocity	90–190 cm/s	Use only when a shunt is present. Out-of-range velocity, focal gradient or turbulence suggests dysfunction according to local protocol.usual: 90–190 cm/scaution zone: 50–90 ou 190–250 cm/slikely dysfunction: <50 ou >250 cm/s, oclusão ou gradiente focal

Classifications and calculators

Calculator — LI-RADS US (HCC surveillance)

Category	Meaning	Management
US-1	Negative	Semiannual US surveillance (± AFP).
US-2	Subthreshold (nodule <10 mm)	Repeat US in 3–6 months.
US-3	Positive (nodule ≥10 mm or new thrombus)	Multiphase CT/MRI or CEUS LI-RADS.

Visualization score A/B/C measures study limitation (steatosis, ascites, body habitus). Severe visualization C may warrant alternative imaging. Apply only in at-risk patients (cirrhosis, hepatitis B).

Source: ACR LI-RADS US Surveillance v2024 / AASLD

Calculator — acute cholecystitis (Tokyo TG18)

Criterion/grade	Definition
A — local inflammation	Sonographic Murphy; wall >4 mm, distension or impacted stone.
B — systemic inflammation	Fever, elevated CRP or WBC.
Diagnosis	A + B = definite acute cholecystitis.
Severity I/II/III	III = organ dysfunction; II = WBC >18k, mass, >72 h or marked local inflammation; I = mild.

Severity guides the timing of cholecystectomy and the need for drainage/support.

Source: Tokyo Guidelines TG18 (J Hepatobiliary Pancreat Sci 2018)

Hepatic CEUS — enhancement of focal lesions

Pattern	Phases	Suggests
Peripheral discontinuous nodular + centripetal fill-in	Arterial→late	Hemangioma
Homogeneous with central scar	Arterial	Focal nodular hyperplasia
Arterial hyperenhancement + late washout	Arterial→late	HCC (use CEUS LI-RADS)
Early, marked washout	Early portal	Metastasis/cholangiocarcinoma

CEUS assesses real-time enhancement without radiation; early/late washout helps separate benign from malignant. Microbubble contrast is purely intravascular.

Source: CEUS LI-RADS v2017 / EFSUMB CEUS guidelines 2020

Quick calculator — upper abdomen

Color	Practical range	How to use
Green	Liver ≤15 cm; spleen ≤12 cm; common bile duct ≤6 mm; gallbladder wall ≤3 mm; aorta <2.5 cm; portal vein 6–13 mm and 16–40 cm/s; pancreatic duct in body ≤2 mm.	Values references tend to agree are usual.
Yellow	Liver >15–16; spleen >12–13; common bile duct >6–7 or older adult; post-cholecystectomy 8–10; wall >3–4; aorta 2.5–2.9; portal vein 13–16 or 12–16 cm/s; duct 2–3.	Divergent zone or dependent on age, fasting, body habitus, inspiration and symptoms.
Red	Common bile duct >7 mm without benign context or >10 mm after cholecystectomy; intrahepatic ducts >2 mm; gallbladder wall >4 mm; spleen >13 cm; aorta ≥3 cm; pancreatic duct >3 mm.	Ranges where sources converge toward abnormality or investigation according to clinical context.

The calculator classifies isolated measurements; it does not replace the report, comparison, labs or associated signs.

Source: CBR / EFSUMB / SRU / USPSTF / ACC-AHA / ASE

Bile ducts — common bile duct and intrahepatic ducts

Category	Measurement	Interpretation
Consensus normal	Common bile duct ≤6 mm with gallbladder; intrahepatic ducts not visible or ≤1 mm.	Without other signs, usually normal.
Context zone	Common bile duct >6–7 mm; up to 8 mm in older adults; 8–10 mm after cholecystectomy; intrahepatic ducts 1–2 mm.	Correlate with age, opioids, surgery, pain, fever and bilirubin.
Likely dilatation	Common bile duct >7 mm with gallbladder and no benign cause; >10 mm after cholecystectomy; intrahepatic ducts >2 mm.	Look for obstruction, distal stone, mass or stricture depending on presentation.

Measure inner wall to inner wall and follow the duct to the pancreatic head when possible.

Source: EFSUMB hepatobiliary chapter / Cleveland Clinic J Med 2022

Gallbladder — wall and polyps

Finding	Range	Reference approach
Fasting wall	≤3 mm	Normal when the gallbladder is well distended.
Fasting wall	>3–4 mm	Borderline; check fasting, contraction, ascites, liver disease and pain.
Fasting wall	>4 mm	Relevant thickening, especially with stone, pericholecystic fluid or sonographic Murphy sign.
Low-risk polyp	<6 mm	Low risk in most guidelines.
Intermediate polyp	6–9 mm ou 10–14 mm baixo risco SRU	SRU versus Europe divergence; consider morphology, growth and risk factors.
High-risk polyp	≥10 mm com fatores de risco ou ≥15 mm	Consider surgery/referral according to guideline and clinical context.

SRU 2022 uses morphology categories and tends to reduce follow-up; European guidelines are more cautious at ≥10 mm.

Source: SRU Radiology 2022 / ESGAR-EAES-EFISDS-ESGE 2022

Abdominal aorta — aneurysm screening

Range	Classification	Note
<2,5 cm	Usual diameter	Below ectasia.
2,5–2,9 cm	Ectasia	Does not meet classic aneurysm criterion, but should be documented.
≥3,0 cm	Abdominal aortic aneurysm	Criterion used in ultrasound screening programs.
≥5,0 cm mulher / ≥5,5 cm homem	Usual repair threshold	Depends on symptoms, growth, anatomy and surgical risk.

Source: USPSTF / ACC-AHA 2022 / Society for Vascular Surgery

Portal vein — diameter, velocity and direction

Color	Criterion	Reading
Green	6–13 mm, velocity 16–40 cm/s, hepatopetal flow	Usual range.
Yellow	13–16 mm with deep inspiration or post-prandial state; velocity 12–16 cm/s	Correlate with spleen, ascites, collaterals and liver surface.
Red	>16 mm, velocity <12 cm/s, hepatofugal flow or thrombosis	Suggests portal hypertension or vascular disease depending on context.

Source: Polish Ultrasound Society portal system standards / StatPearls

Pancreas and inferior vena cava — useful limits

Structure	Normal	Alert
Main pancreatic duct in body	≤2 mm	Usual range in pancreatic body.
Main pancreatic duct	>2–3 mm	High-normal/borderline, especially in older adults or at the head.
Main pancreatic duct	>3 mm	Likely dilatation; consider cross-sectional imaging according to symptoms and findings.
Inferior vena cava	<2,1 cm + colapso >50%	Compatible with low/normal right atrial pressure.
Inferior vena cava	discordant findings	Indeterminate; use secondary indices and context.
Inferior vena cava	>2,1 cm + colapso <50%	Suggests elevated right atrial pressure.

Source: EFSUMB pancreas / Pancreatic ultrasound update 2024 / ASE chamber quantification

Quick assistant — abdominal Doppler

Output	Color	Interpretation
Preserved Doppler	Green	Patent portal vein with flow toward the liver, usual velocity, hepatic artery with usual resistive index and phasic hepatic veins.
Contextual or limited finding	Yellow	Slow portal flow, borderline hepatic artery, monophasic hepatic vein without thrombus, isolated ascites/splenomegaly or technical limitation.
Abnormal vascular finding	Red	Hepatofugal portal flow, absent flow, thrombosis, cavernoma, portosystemic collaterals, hepatic vein/caval obstruction or shunt dysfunction.

Do not use velocity alone as the conclusion. Combine direction, patency, waveform, diameter, spleen, ascites, collaterals, technique and clinical indication.

Source: StatPearls Liver Doppler / Radiographics liver Doppler / portal hypertension reviews

Technical protocol — hepatoportal Doppler

Item	Record	Why it matters
Main portal vein and branches	Patency, direction toward or away from the liver, velocity and diameter.	Basis for portal hypertension, thrombosis and collateral flow.
Hepatic artery	Resistive index, systolic velocity and systolic upstroke when indicated.	Helps in transplant, portal thrombosis, stenosis and arterial compensation.
Hepatic veins and inferior vena cava	Phasicity, patency, thrombus, compression or dilation.	Assesses congestion, Budd-Chiari, right-heart disease and venous obstruction.
Splenic vein and portal confluence	Patency, direction, thrombus and collaterals.	Important in portal/splenic thrombosis and segmental portal hypertension.
Technique	Fasting, acoustic window, angle up to 60 degrees, scale/filter and limitations.	Avoids false diagnosis of thrombosis from slow flow.

Source: ACR-AIUM-SPR-SRU abdomen parameter / StatPearls Liver Doppler

Portal hypertension and thrombosis — Doppler signs

Color	Sign	Comment
Green	Patent portal vein, flow toward the liver, 16-40 cm/s, no collaterals.	Compatible with usual hemodynamics when B-mode agrees.
Yellow	Velocity 12-16 cm/s, diameter 13-16 mm, enlarged spleen or isolated ascites.	Context zone; look for a combination of signs.
Red	Flow away from the liver, absent flow, thrombus, cavernoma, recanalized umbilical vein or collaterals.	Strong findings for advanced portal hypertension or thrombosis.

Source: StatPearls Liver Doppler / Doppler flow patterns in cirrhosis reviews

Hepatic artery, hepatic veins and inferior vena cava — practical reading

Structure	Green	Yellow	Red
Hepatic artery	Resistive index 0.50-0.70 and present diastole.	0.70-0.80 or 0.45-0.50 without another warning.	>0.80, <0.45, absent flow or tardus-parvus.
Hepatic veins	Triphasic/phasic.	Monophasic with cirrhosis, technique or likely congestion.	Thrombus, absent flow, stenosis or venous collaterals.
Inferior vena cava	Patent, compressible/phasic according to respiration and heart.	Dilated with reduced collapse in congestion.	Thrombus, tumor compression or thrombus extension.
Transjugular intrahepatic portosystemic shunt	90-190 cm/s without focal gradient.	50-90 or 190-250 cm/s.	<50, >250 cm/s, occlusion or focal turbulence/gradient.

These thresholds are most useful in the right context. Transplant and shunt exams have their own protocols and serial comparison is essential.

Source: StatPearls Liver Doppler / institutional TIPS protocols / AJR liver Doppler

Hepatic Doppler / liver transplant

Applies to native liver, postoperative studies and liver transplant. Arterial, portal and venous criteria are used internationally, but final weight depends on postoperative timing, surgical technique, serial comparison and institutional protocol. In Brazil, keep anatomic description clear and communicate critical findings; in the US/Europe, align with ACR-AIUM, RSNA/Radiographics and local transplant protocols.

Measurements and reference values

Measurement	Usual value	Note
Transplant hepatic artery — resistive index	0,55–0,80	High values may be transient in the first 48-72 h; low index with tardus-parvus favors stenosis.usual: 0,55–0,80borderline or transient: 0,50–0,55 ou >0,80 nas primeiras 72 h sem outro alertahigh risk: <0,50 com tardus-parvus, ausência de fluxo ou piora clínica
Hepatic artery — systolic acceleration time	< 80 ms	Above 80 ms is used with low resistive index and tardus-parvus waveform to suspect stenosis.brisk upstroke: <80 mstechnical zone: 80–100 ms sem baixo índice de resistênciastenosis concern: >80 ms + índice baixo/tardus-parvus
Hepatic artery — focal peak systolic velocity	< 200 cm/s	Velocity >=200 cm/s at the jet/anastomosis, especially with aliasing and distal waveform change, favors stenosis.no focal elevation: <150 cm/scaution: 150–199 cm/sstrong concern: ≥200 cm/s com gradiente/turbulência
Hepatic artery — absent flow	critical abnormality if confirmed	Confirm with low/high gain, slow scale, power Doppler and intra/extrahepatic search.communicate: arterial thrombosis until proven otherwise in transplant
Portal vein — flow direction	toward the liver	Flow away from the liver or no flow is abnormal in the graft unless there is an intended shunt.expected: toward the liverborderline: very slow or to-and-froabnormal: away from liver, thrombus or no flow
Transplanted portal vein — anastomotic velocity	< 125 cm/s	Some protocols accept high velocities early postoperatively; ratio and turbulence increase specificity.usual: <100 cm/s sem turbulênciaobserve: 100–124 cm/s ou edema precocestenosis concern: ≥125 cm/s com aliasing ou razão elevada
Portal vein — anastomosis/reference ratio	< 3:1	Ratio >=3:1 is a strong criterion when there is focal narrowing, turbulence or serial change.no gradient: <2:1borderline: 2–2,9:1significant: ≥3:1
Hepatic veins and inferior vena cava — waveform	phasic/triphasic	Isolated monophasic waveform can be nonspecific; absent flow, focal jet and elevated ratio suggest outflow obstruction.reassuring: phasic or triphasiccontextual: monophasic without jet/congestionlikely obstruction: no flow, thrombus, focal jet or ratio >=3:1
Transjugular intrahepatic portosystemic shunt — velocity	90–190 cm/s	Included for differentiation; do not confuse a shunt with the transplant portal anastomosis.usual: 90–190 cm/scaution zone: 50–90 ou 190–250 cm/slikely dysfunction: <50, >250, oclusão ou gradiente focal

Classifications and calculators

Interactive assistant — hepatic and transplant Doppler

Output	Color	Interpretation
Preserved pattern	Green	Patent hepatic artery, usual resistive index, brisk upstroke, portal flow toward the liver and phasic hepatic veins.
Borderline/contextual zone	Yellow	High index early postoperatively, intermediate velocity, isolated monophasic waveform or technical limitation.
Vascular alert	Red	Absent arterial flow, tardus-parvus with low index, arterial velocity >=200 cm/s, portal thrombus, portal/venous ratio >=3:1 or venous obstruction.

The assistant calculates ratios and color-codes results. In transplant, comparison with baseline Doppler can be more important than an isolated number.

Source: Radiographics/RSNA / Clinical Imaging / AJR / UW and UT Southwestern transplant Doppler protocols

Minimum technical protocol — native liver and transplant

Vessel/step	Record	Why it matters
Main hepatic artery and intrahepatic branches	Patency, resistive index, systolic velocity, systolic upstroke and sample location.	Main screening for post-transplant arterial thrombosis or stenosis.
Main portal vein, anastomosis and branches	Direction, jet velocity and reference velocity before/after.	Differentiates transient hyperflow from anastomotic stenosis.
Hepatic veins and inferior vena cava	Phasicity, focal jet, anastomotic velocity, ratio and residual flow.	Assesses outflow obstruction and graft congestion.
Surgical context	Transplant date, graft type, caval technique, stent, angioplasty and baseline exam.	Changes thresholds and avoids false positives early postoperatively.
Doppler technique	Angle up to 60 degrees, low scale for slow flow, adjusted gain, power Doppler when needed.	Avoids simulating thrombosis from slow flow or poor window.

Source: ACR-AIUM-SPR-SRU abdomen parameter / UW Liver TX Doppler / UTSW transplant protocol

Post-transplant hepatic artery — color reading

Color	Criterion	Practical reading
Green	Flow present, index 0.55-0.80, acceleration time <80 ms, no focal jet.	Compatible with arterial patency when the tracing is reliable.
Yellow	Index >0.80 in the first 72 h, velocity 150-199 cm/s or technically limited tracing.	Repeat/follow, compare with baseline and correlate with labs.
Red	No flow, index <0.50 with tardus-parvus, time >80 ms with low index, focal velocity >=200 cm/s.	Priority communication; consider complementary imaging or intervention according to protocol.

Isolated high index early postoperatively is a known pitfall; the same late finding or with graft dysfunction carries more weight.

Source: Radiographics/RSNA liver transplant Doppler / Clinical Imaging 2014

Transplanted portal vein — stenosis, thrombosis and hyperflow

Color	Finding	Interpretation
Green	Flow toward the liver, no thrombus, velocity <100 cm/s and ratio <2:1.	Usual pattern when there is no focal aliasing.
Yellow	Velocity 100-124 cm/s, ratio 2-2.9:1 or high early postoperative velocity without narrowing.	Zone dependent on edema, caliber and comparison.
Red	Velocity >=125 cm/s with aliasing, ratio >=3:1, thrombus or absent flow.	Suggests portal stenosis, thrombosis or critical flow.

Source: Radiographics/RSNA / Doppler ultrasound in liver transplant complications

Graft venous outflow — hepatic veins and inferior vena cava

Color	Finding	Reading
Green	Phasic/triphasic hepatic veins and patent cava.	Against important outflow obstruction when the rest agrees.
Yellow	Isolated monophasic waveform, mild damping or poor respiratory/technical exam.	Nonspecific; repeat and correlate with ascites, pleural effusion and congestion.
Red	No flow, thrombus, focal jet, important aliasing or ratio >=3:1.	Suggests venous outflow stenosis/occlusion.

Source: UW Liver TX Doppler / RSNA transplant imaging reviews

Native liver — hepatic Doppler outside transplant

Structure	Consensus normal	Alert
Portal vein	Flow toward the liver, diameter 6-13 mm, mean velocity 16-40 cm/s.	Flow away from liver, thrombus, cavernoma, collaterals or very slow flow.
Hepatic artery	Resistive index 0.50-0.70 outside transplant, with present diastole.	Absent flow, extreme index or tardus-parvus in the right context.
Hepatic veins	Phasic/triphasic tracing.	No flow, thrombus, compression or obstructive pattern.

In the native liver, isolated numbers rarely make the diagnosis; flow direction, thrombus, collaterals and clinical context dominate.

Source: StatPearls Liver Doppler / Radiographics liver Doppler

Pitfalls and when to escalate

Situation	Error risk	How to reduce
First 72 hours	High arterial index may reflect edema, spasm or transient increased resistance.	Compare serially and weigh graft function.
Slow flow	High scale or high wall filter may simulate thrombosis.	Lower scale, adjust gain and use power Doppler.
No arterial flow in transplant	May represent arterial thrombosis, a time-sensitive event.	Confirm technically and communicate immediately according to local workflow.
Late arterial stenosis	May cause biliary ischemia, abscesses or progressive dysfunction.	Integrate Doppler with bile ducts, collections and labs.

Source: Radiographics/RSNA / Clinical Imaging review / transplant protocols

Report checklist — hepatic/transplant Doppler

Block	Text that should not be missing	Color if absent
Identification	Time after transplant, graft/anastomosis type if known, prior comparison.	Yellow
Hepatic artery	Patency, resistive index, velocity, acceleration time and presence/absence of tardus-parvus.	Red if transplant
Portal vein	Direction, anastomotic velocity, ratio if suspicious, thrombus and branches.	Red if vascular concern
Venous outflow	Hepatic veins, cava, phasicity, focal jet and ratio when stenosis is suspected.	Yellow/red according to finding
Associated findings	Bile ducts, collections, ascites, pleural effusion and technical limitation.	Yellow

Source: CBR reporting principles / ACR-AIUM practice parameter / transplant Doppler literature

Thyroid / cervical

Measurements and reference values

Measurement	Usual value	Note
Right/left lobe — length	4–6 cm	adult; measure each lobe separately
Right/left lobe — width	1–2 cm
Right/left lobe — anteroposterior thickness	1,3–1,8 cm	up to ~2.0 cm may be accepted by some references
Total thyroid volume — female	10–15 mL	usual range; classic upper limit for goiter: >18 mL
Total thyroid volume — male	12–18 mL	25 mL is better treated as a classic upper limit, not as a normality target
Volume calculation for each lobe	C × L × E × 0,479	length, width and thickness in cm; add both lobes
Isthmus — thickness	≤ 3–4 mm
Thyroid parenchyma — color Doppler	sparse to moderate and symmetric	Marked diffuse hypervascularity is abnormal and should be correlated with TSH, free T4 and antibodies.
Thyroid arteries — peak systolic velocity	see bands cm/s	There is no universal cutoff: 30 to 70 cm/s is an overlap zone across studies; above ~70 cm/s favors Graves hyperflow when the pattern is diffuse.Green — no relevant hyperflow: <30 cm/sYellow — overlap zone: 30–69 cm/sRed — marked hyperflow: ≥70 cm/s

Classifications and calculators

Calculator — EU-TIRADS (European alternative)

Category	Risk	FNA from
EU-TIRADS 2	~0% (anechoic/spongiform)	—
EU-TIRADS 3	2–4% (low risk)	≥20 mm
EU-TIRADS 4	6–17% (intermediate)	≥15 mm
EU-TIRADS 5	26–87% (high risk)	≥10 mm

High-risk signs (EU-TIRADS 5): markedly hypoechoic, irregular margins, taller-than-wide, microcalcifications. Always compare with ACR TI-RADS.

Source: EU-TIRADS — Russ, Eur Thyroid J 2017 (ETA)

Calculator — Bethesda (thyroid cytology)

Category	Malignancy risk	Usual management
I	5–20% (nondiagnostic)	Repeat US-guided FNA.
II	0–3% (benign)	Follow-up per sonographic risk.
III	6–18% (AUS)	Repeat FNA, molecular test or lobectomy.
IV	10–40% (follicular neoplasm)	Molecular test or diagnostic lobectomy.
V	45–60% (suspicious)	Surgery per extent.
VI	94–99% (malignant)	Surgery + staging.

Bethesda is cytology (FNA); US (ACR/EU-TIRADS) decides WHO to biopsy. Risks assume no NIFTP; molecular testing refines III and IV.

Source: The Bethesda System, 3rd ed. 2023

ACR TI-RADS 2017 — feature scoring

Feature	Finding	Points	Practical note
Composition	Cystic or almost completely cystic	0	Does not add suspicion points in ACR.
Composition	Spongiform	0	Multiple microcysts occupying more than 50% of the nodule.
Composition	Mixed cystic and solid	1	Score by the described predominant composition.
Composition	Solid or almost completely solid	2	Feature that increases the score but does not define the level alone.
Echogenicity	Anechoic	0	Applies to a cystic nodule.
Echogenicity	Isoechoic or hyperechoic	1	Compare with adjacent thyroid parenchyma.
Echogenicity	Hypoechoic	2	Darker than thyroid, but not darker than muscle.
Echogenicity	Very hypoechoic	3	Darker than the anterior neck musculature.
Echogenicity	Cannot be determined	1	ACR assigns 1 point when echogenicity cannot be determined.
Shape	Wider-than-tall	0	Assess on the transverse plane.
Shape	Taller-than-wide	3	Higher-suspicion sign in ACR TI-RADS.
Margin	Smooth	0	Regular margin.
Margin	Ill-defined	0	Not the same as irregular; does not score in ACR.
Margin	Lobulated or irregular	2	Scores as a suspicious margin.
Margin	Extrathyroidal extension	3	Frank invasion beyond the thyroid capsule.
Margin	Cannot be determined	0	Use when the margin cannot be assessed confidently.
Echogenic foci	None or large comet-tail artifact	0	Large colloid artifact is benign in the system.
Echogenic foci	Macrocalcifications	1	Larger calcified focus with posterior shadowing.
Echogenic foci	Peripheral rim calcifications	2	Score if present; may coexist with other foci.
Echogenic foci	Punctate echogenic foci	3	May represent microcalcifications; add with other foci present.

Choose one option for composition, echogenicity, shape and margin. For echogenic foci, add all findings present; if none, use 0 points.

Source: ACR TI-RADS white paper 2017 / ACR TI-RADS Atlas

ACR TI-RADS 2017 — thyroid nodule

Level	Points	Risk	FNA from	Imaging follow-up
TR1	0	0,3%	—	—
TR2	1–2	1,5%	—	—
TR3	3	4,8%	≥ 2,5 cm	≥ 1,5 cm: 1, 3 e 5 anos
TR4	4–6	9,1%	≥ 1,5 cm	≥ 1,0 cm: 1, 2, 3 e 5 anos
TR5	≥ 7	35%	≥ 1,0 cm	≥ 0,5 cm: anual por 5 anos

Add composition, echogenicity, shape, margin and echogenic foci. Management uses the nodule largest dimension.

Source: ACR TI-RADS — JACR 2017

Thyroid Doppler — quick reading

Category	Range / pattern	Interpretation
Parenchyma	Sparse to moderate symmetric vascularity	Expected pattern when there is no diffuse hyperemia.
Parenchyma	Mild/moderate, focal or asymmetric increase	Overlap finding: correlate with grayscale, pain, TSH, free T4 and antibodies.
Parenchyma	Marked diffuse hyperflow (“thyroid inferno”)	Abnormal; in diffusely enlarged thyroid it favors Graves when laboratory tests agree.
Peak systolic velocity	<30 cm/s	Green range because it matches resting values in several series.
Peak systolic velocity	30–69 cm/s	Borderline zone: studies use 30 or 40 cm/s, but a recent meta-analysis points to a higher cutoff.
Peak systolic velocity	≥70 cm/s	Marked hyperflow; strengthens Graves hypothesis if the increase is diffuse.

Doppler does not replace laboratory tests or scintigraphy when needed. Use this reading to guide description and clinical correlation.

Source: Frontiers Endocrinol 2024 meta-analysis / Arch Endocrinol Metab 2019 / QJM 2025

Chammas — nodule vascularization (Doppler)

Pattern	Description	Color	Practical note
I	No flow	Green	Lower Doppler suspicion; still apply ACR TI-RADS by grayscale.
II	Peripheral/perinodular only	Green	Relatively lower-suspicion pattern.
III	Peripheral equal to or greater than central	Yellow	Intermediate finding; does not change management alone.
IV	Central greater than peripheral	Red	Higher specificity for malignant cytology, but low sensitivity.
V	Exclusively central	Red	Higher adjunct Doppler suspicion; does not replace cytology.

Nodule vascular Doppler is complementary: a European study showed vascularity does not improve overall ACR TI-RADS stratification. Chammas IV/V patterns are specific but poorly sensitive.

Source: Chammas et al. / AEM-SBEM 2009 / Eur Thyroid J 2021

Cervical lymph node — suspicious signs

Sign	Suspicious finding
Shape	Rounded: long axis less than twice the short axis
Hilum	Absent
Vascularity	Peripheral/chaotic
Echotexture	Microcalcifications, cystic, hyperechoic

Source: Critérios sonográficos consagrados

Venous Doppler and mapping — limbs, jugular and subclavian veins

Integrates deep and superficial venous thrombosis assessment, reflux/varicose-vein mapping, pre-procedure planning, saphenous mapping for graft, jugular/subclavian veins and indirect signs of central venous obstruction. Green means technically complete and consensually normal findings; yellow means limitation, post-thrombotic change, borderline reflux, variable anatomy or guideline divergence; red means thrombosis, obstruction, consensual pathologic reflux or urgent sign.

Measurements and reference values

Measurement	Usual value	Note
Lower limbs — thrombosis assessment	serial compression	Document common femoral vein, saphenofemoral junction, proximal/mid/distal femoral vein, popliteal vein, posterior tibial and peroneal veins; add gastrocnemius, soleal and superficial veins when symptomatic.consensus normal: compressible, patent, phasic and without intraluminal materialincomplete or indeterminate: segment not seen, limited calf or post-thrombotic changeconsensus abnormal: noncompressible vein, thrombus or absent flow after technical optimization
Venous mapping for varicose veins — technique	standing + standardized maneuvers	Assess reflux preferably standing. Use Valsalva at the common femoral vein and saphenofemoral junction; use distal compression/release for the other segments. Record position, maneuver and reflux time on spectral Doppler.adequate technique: standing or dependent position, documented maneuvertechnical limitation: not standing, pain, dressing, obesity or poor maneuverdo not interpret as complete mapping: reflux assessed only supine without justification
Great saphenous vein — minimum mapping points	junction + thigh + calf	Document the saphenofemoral junction, anteroposterior great saphenous caliber in thigh and calf, reflux extent, source, drainage, tributaries, accessory saphenous veins and any subdermal or hypoplastic course.complete map: calibers + reflux + source/drainage by segmentincomplete map: no calibers, no source/drainage or no accessory-vein descriptionassociated critical finding: thrombosis, stump ascending to deep junction or suspected deep extension
Small saphenous vein — minimum mapping points	junction + knee distance + calf	The saphenopopliteal junction is variable; record distance to the knee joint line/crease, small saphenous caliber by segment, cranial extension, Giacomini vein and reflux drainage.useful description: junction, knee distance, caliber and cranial extension describedvariable anatomy: no typical junction, cranial extension/Giacomini or complex drainagecomplication: superficial thrombosis near deep junction or extension into deep system
Saphenous vein mapping for graft	caliber + continuity + compressibility	Describe by segment: diameter, compressibility, continuity, varicosities, thrombosis, bifurcations, superficial course and usable length. Acceptable caliber varies by service; as a teaching safety rule, less than 2 mm is red, 2-2.9 mm yellow and 3 mm or more green if wall and course are suitable.favorable: ≥3 mm, compressible, continuous and without varicosity/thrombosisborderline: 2-2.9 mm or short usable segmentunfavorable: <2 mm, thrombosed, markedly varicose or discontinuous
Superficial reflux — saphenous, accessory and tributary veins	> 0,5 s	Preferably assess standing or in dependent position, with standardized provocation and reflux time measured on spectral Doppler.normal: up to 0.5 sborderline/technical: 0.45-0.50 s or inadequate maneuver/positionpathologic reflux: greater than 0.5 s
Deep reflux — femoropopliteal segment	> 1,0 s	For common femoral, femoral and popliteal veins, many consensus documents use greater than 1.0 s; other deep segments use greater than 0.5 s.normal: up to 1.0 s in the femoropopliteal segmentgray zone: 0.8-1.0 s or inconsistent techniquedeep reflux: greater than 1.0 s in the femoropopliteal segment
Perforator veins	> 0,35–0,50 s	There is divergence between 0.35 s and 0.50 s. Brazilian consensus accepts greater than 0.35 s; international treatment criteria often require greater than 0.5 s and diameter greater than 3.5 mm, especially beneath ulcerated or damaged skin.consensus normal: less than 0.35 sguideline divergence: 0.35-0.50 s or without diameter/contextmore accepted abnormal: greater than 0.50 s with diameter above 3.5 mm or related skin/ulcer change
Upper limbs, jugular and subclavian veins	compression when possible + Doppler	Internal jugular, axillary, brachial, basilic and cephalic veins should be compressed when possible; the subclavian vein is partly limited by the clavicle and relies more on color, spectral waveform, phasicity and contralateral comparison.normal: compressible where possible, spontaneous, phasic and symmetric flowanatomic limitation: subclavian vein not fully compressible but normal Dopplerobstruction/thrombosis: noncompressible, absent filling, collaterals or asymmetric continuous waveform
Superficial venous thrombosis	noncompressibility + thrombus	Describe extent, distance from the deep junction, involved vein and inflammatory signs. Proximity to the saphenofemoral/saphenopopliteal junction or extension into the deep system increases severity.absent: compressible and patent superficial veinlocalized superficial: superficial thrombus away from deep systemhigh risk: near deep junction, extensive, ascending or with associated deep thrombosis

Classifications and calculators

Interactive assistant — thrombosis, reflux and venous obstruction

Output	Color	Practical use
Patent/normal	Green	Preserved compressibility, phasic/symmetric flow and reflux below accepted cutoffs.
Indeterminate, limited or post-thrombotic	Yellow	Use when there is technical limitation, anatomically noncompressible subclavian vein, borderline reflux or post-thrombotic scarring.
Thrombosis, obstruction or pathologic reflux	Red	Noncompressible vein, thrombus, absent flow, central collaterals, asymmetric continuous waveform or reflux clearly above cutoffs.

The calculator does not replace clinical probability, D-dimer, serial follow-up or venography/CT/MR venography when central suspicion remains high.

Source: SRU 2018 / ACR-AIUM-SPR-SRU / IAC / AVF 2026

Varicose-vein mapping — technical checklist

Step	What to document	Teaching color
Deep system first	Compressibility, patency, phasicity and deep reflux when the study is for venous insufficiency.	Green if complete and normal
Great saphenous vein	Saphenofemoral junction, thigh and calf caliber, terminal/preterminal/segmental reflux, source and drainage.	Green if no reflux and well documented
Small saphenous vein	Saphenopopliteal junction, distance to knee, caliber, cranial extension, Giacomini vein and drainage.	Yellow when anatomy is variable
Tributaries and accessory veins	Map the source and drainage of reflux; do not call every channel saphenous without identifying the involved trunk.	Yellow if topography is missing
Perforator veins	Site, distance from knee or sole, diameter, reflux and relationship to skin/ulcer.	Yellow/red according to reflux and diameter
Thrombosis or deep extension	Noncompressible vein, saphenous thrombus near deep junction, extension into the deep system or phlegmasia.	Red

The map should be anatomic and functional: where reflux starts, where it travels, where it drains and which segments are treatable.

Source: CBR-SBACV-SP 2020 / SVS-AVF-AVLS 2023 / ESVS 2022

Saphenous veins — reflux patterns for reporting

Pattern	How to recognize	How to report
Terminal reflux	Incompetent terminal valve/junction with reflux entering the saphenous trunk.	State junction, cranio-caudal extent and drainage into tributaries/perforators.
Preterminal reflux	Competent terminal valve, but reflux below the junction through tributary, accessory vein or perforator.	Differentiate from junction incompetence to avoid overtreatment.
Segmental reflux	Limited saphenous segment with reflux and normal segments above/below.	Describe start, end and connections.
Tributary or accessory-vein reflux	The saphenous trunk may be competent, but reflux is present in an anterior/posterior accessory or tributary vein.	Name the vein and its relationship to the saphenous compartment.
Giacomini vein or cranial extension of the small saphenous	Connection of the small saphenous vein with thigh veins/great saphenous vein.	Record course and drainage direction.
Post-surgical or recurrent varices	Stump, neovascularization, residual saphenous vein, incompetent accessory vein or incompetent perforator.	Report recurrence source instead of only “varices”.

Source: CBR-SBACV-SP 2020 / Caggiati nomenclature / local report corpus

Perforators — color reading

Color	Criterion	Interpretation
Green	No reflux or reflux less than 0.35 s.	Do not call it an incompetent perforator by diameter alone.
Yellow	Reflux 0.35-0.50 s, isolated diameter greater than 3.5 mm or incomplete topography.	Divergence zone: document and correlate with skin, ulcer and varices.
Red	Reflux greater than 0.50 s with diameter greater than 3.5 mm, especially beneath skin change or ulcer.	More accepted criterion for pathologic/treatable perforator.

Brazilian consensus accepts greater than 0.35 s as perforator reflux; international treatment criteria more often use reflux greater than 0.5 s plus diameter greater than 3.5 mm.

Source: CBR-SBACV-SP 2020 / SVS-AVF-AVLS 2023 / ESVS 2022 / CMS LCD

Saphenous graft mapping — practical table

Color	Finding	Report action
Green	Continuous, compressible saphenous vein without thrombosis/marked varicosity and generally 3 mm or larger.	Report usable length and segmental calibers.
Yellow	Caliber 2-2.9 mm, bifurcations, short segment, superficial course or irregular wall.	Describe limitations without universally rejecting; decision is surgical.
Red	Caliber less than 2 mm, thrombosis, marked varicosity, discontinuity or post-ablation.	Flag as unfavorable and look for an alternative if requested.

Source: vascular lab vein mapping protocols / CBR-SBACV-SP 2020

Venous thrombosis assessment — color reading

Color	Finding	Interpretation
Green	Compressible vein, no intraluminal material, color flow and phasic waveform.	Normal in the assessed segment if the study was complete.
Yellow	Equivocal partial compression, unseen segment, limited calf or chronic wall-adherent change.	Report limitation and consider serial follow-up or complementary imaging according to clinical risk.
Red	Noncompressible vein, intraluminal material, absent filling, free-floating thrombus or proximal extension.	Compatible with thrombosis/occlusion until proven otherwise; communicate according to local protocol.

Source: SRU 2018 / ACR-AIUM-SPR-SRU / IAC

Venous reflux — teaching cutoffs by segment

Segment	Green	Yellow	Red
Saphenous, accessory and tributary veins	up to 0.5 s	0.45-0.50 s or poor technique	greater than 0.5 s
Common femoral, femoral and popliteal veins	up to 1.0 s	0.8-1.0 s or inadequate maneuver	greater than 1.0 s
Perforator veins	less than 0.35 s	0.35-0.50 s or no clinical context	greater than 0.50 s, especially if diameter greater than 3.5 mm
Deep veins below the knee	up to 0.5 s in many references	technique-dependent	greater than 0.5 s when reproducible

Always record patient position, maneuver and reflux source/drainage. Reversed flow from proximal obstruction should not be called valvular reflux.

Source: CBR-SBACV-SP 2020 / SVS-AVF / ESVS 2022 / CMS LCD

Jugular, subclavian and suspected central obstruction

Site	Practical assessment	Warning sign
Internal jugular vein	Direct compression, color and spectral Doppler.	Noncompressibility or thrombus.
Subclavian vein	Compression limited by clavicle; use color filling, phasicity, pulsatility and comparison with the opposite side.	Asymmetric continuous/monophasic waveform, little respiratory variation or collaterals.
Brachiocephalic veins and superior vena cava	Usually indirect assessment; consider CT, MRI or venography if suspicion remains high.	Face/arm edema, chest-wall collaterals, catheter or pacemaker with abnormal central waveform.

Source: ACR Appropriateness Criteria 2020 / SVU 2019 / AVF 2026

CEAP clinical classification — chronic venous disease

Class	Clinical finding	Teaching color
C0	No visible or palpable signs	Green
C1	Telangiectasias or reticular veins	Yellow if symptomatic
C2	Varicose veins	Yellow
C3	Venous edema	Yellow
C4	Skin changes from venous disease	Red
C5	Healed venous ulcer	Red
C6	Active venous ulcer	Red

CEAP is a clinical classification; color here is educational and does not replace the complete clinical category with etiology, anatomy and pathophysiology.

Source: AVF CEAP 2020 / ESVS 2022

Useful differentials when it is not thrombosis

Scenario	Possibilities	Ultrasound clue
Calf pain and swelling	Ruptured popliteal cyst, muscle injury, hematoma, cellulitis, lymphedema.	Compressible veins and explanatory extravascular finding.
Bilateral edema	Cardiac, renal, hepatic, medication-related or lymphatic cause.	Patent venous flow; assess symmetry and systemic context.
Arm/face edema or chest-wall collaterals	Central venous obstruction from catheter, pacemaker, mass or central thrombosis.	Asymmetric continuous waveform, loss of phasicity or collaterals.
Severe pain with very swollen limb	Extensive thrombosis, phlegmasia, compartment syndrome or severe infection.	Urgent communication even before completing broad mapping.

Source: SRU 2018 / ACR-AIUM-SPR-SRU / CBR-SBACV-SP

Aorta and iliac vessels — arteries and veins

Dedicated category for the aortoiliac axis: screening/follow-up of abdominal aortic aneurysm, iliac artery aneurysm/ectasia, aortoiliac arterial stenosis, iliocaval venous obstruction and post-repair follow-up. Green = consensus normality; yellow = borderline zone, limited technique or divergent guidance; red = aneurysm, stenosis/occlusion, significant venous obstruction, growth, symptoms or complication.

Measurements and reference values

Measurement	Usual value	Note
Abdominal aorta — maximum outer-to-outer diameter	< 3,0 cm	Measure perpendicular to the vessel axis at the largest diameter. Aneurysm starts at 3.0 cm; ectasia 2.5-2.9 cm is a yellow zone.consensus normal: <2,5 cmectasia: 2,5–2,9 cmaneurysm: ≥3,0 cm
Abdominal aortic aneurysm — usual repair threshold	men ≥5.5; women ≥5.0 cm	Also consider vascular evaluation if symptomatic, saccular/pseudoaneurysm, rupture signs or rapid growth.surveillance: 3,0–4,9 cmnear threshold: 5,0–5,4 cmrepair threshold: ≥5.5 cm men; ≥5.0 cm women
Common iliac artery — diameter	< 1.5-1.7 cm	There is divergence: ectasia may be defined from 1.5 cm in women or 1.7 cm in men; many services treat ≥2.0 cm as small aneurysm and ≥3.5 cm as a strong repair threshold.more consensual normal: <1,5 cmectasia/divergent: 1,5–1,9 cmiliac aneurysm: ≥2,0–2,5 cmdiscuss repair: ≥3,5 cm
Aortoiliac arterial stenosis — velocity ratio	≥ 2,0	Ratio between jet velocity and normal proximal segment; use angle below 60 degrees and correlate with aliasing, narrowing and distal waveform.no hemodynamic stenosis: <1,5mild/technical zone: 1,5–1,99stenosis ≥50%: ≥2,0severe: >4,0
Iliac/caval venous obstruction — velocity ratio	> 2,5	Useful but not absolute criterion: integrate with loss of common femoral phasicity, collaterals, extrinsic compression, thrombus, stent and symptoms.likely normal: <2,0 + onda fásicasuspicious/borderline: 2,0–2,5 ou onda pouco fásicasignificant obstruction: >2,5 ou colaterais/no flow
Post-aortic endograft — aneurysm sac	stable or shrinking	Sac growth, endoleak, migration, kinking, limb thrombosis or absent iliac limb flow are warning signs.stable: sac stable/shrinking, no endoleaktype II endoleak without growth: follow per local protocolcomplication: type I/III, growth ≥5 mm, thrombosis/occlusion

Classifications and calculators

Interactive assistant — aorta, iliac arteries and iliac/caval veins

Output	Color	Interpretation
Normal/preserved patency	Green	Aorta <2.5 cm, iliacs without relevant ectasia, arterial ratio <1.5, multiphasic arterial waveform and phasic/symmetric venous waveform.
Borderline, technical or divergent	Yellow	Aorta 2.5-2.9 cm, iliac 1.5-1.9 cm, poor window, venous ratio 2.0-2.5, mildly damped venous waveform or stable post-repair minor finding.
Aneurysm, stenosis, occlusion or obstruction	Red	Aorta ≥3.0 cm, iliac ≥2.0-2.5 cm, arterial ratio ≥2.0, no flow, venous ratio >2.5, collaterals, symptoms or endograft complication.

The assistant classifies ultrasound risk and documentation quality; final management depends on symptoms, sex, growth, anatomy, operative risk and local vascular protocol.

Source: ACC/AHA 2022 / SVS / ESVS 2024 / SVU / IAC / JVS Venous

Abdominal aorta — screening and follow-up

Maximum diameter	Color	Practical reading
<2,5 cm	Green	Normal in most adults; if screening was requested, record maximum measurement and visualized segment.
2,5–2,9 cm	Yellow	Ectasia: below classic aneurysm criterion but should be described; SVS suggests late rescreening when initial screening is >2.5 and <3.0 cm.
3,0–3,9 cm	Red	Small aneurysm; imaging surveillance is usually long-interval, for example 3 years in SVS.
4,0–4,9 cm	Red	Moderate aneurysm; closer surveillance, often yearly.
5,0–5,4 cm	Red	Large or near-threshold aneurysm; usually 6-month surveillance and vascular evaluation.
≥5.5 cm men or ≥5.0 cm women	Red	Usual repair threshold in current guidelines if anatomy and risk allow.

Source: SVS / ACC-AHA 2022 / USPSTF / ESVS 2024

Iliac arteries — diameter and aneurysm

Common iliac diameter	Color	Comment
<1,5 cm	Green	More consensual normality for teaching use.
1,5–1,9 cm	Yellow	Ectasia or divergent zone: some cutoffs vary by sex and body size.
2,0–2,4 cm	Yellow	Many studies call this small aneurysm; rupture risk is low, but documentation and comparison matter.
2,5–3,4 cm	Red	Established iliac aneurysm in radiology/vascular references; assess growth, bilaterality and associated aorta.
≥3,5 cm	Red	Strong threshold for repair discussion in ACC/AHA and ESVS, especially with concomitant aortic aneurysm.

Source: ACC/AHA 2022 / ESVS 2024 / JVS / Radiopaedia

Aortoiliac arterial stenosis — Doppler

Finding	Color	Interpretation
Velocity ratio <1.5 and multiphasic waveform	Green	No hemodynamically relevant stenosis in the assessed segment.
Ratio 1.5-1.99 or isolated jet without good reference	Yellow	Mild/technical zone: check angle, tortuosity, calcification and normal proximal segment.
Ratio ≥2.0, focal aliasing or damped distal waveform	Red	Compatible with hemodynamically significant stenosis, often ≥50%.
Ratio >4.0 or no flow	Red	Severe stenosis/occlusion; document extent, distal reconstitution and collaterals.

Source: ACR-AIUM-SRU arterial Doppler / Society for Vascular Medicine / SVU

Iliac veins and inferior vena cava — obstruction

Finding	Color	Interpretation
Phasic/symmetric common femoral waveform and patent cava/iliac veins	Green	Likely normal when the window is adequate and there are no collaterals.
Reduced phasicity, ratio 2.0-2.5 or unseen segment	Yellow	Suspicion/limitation: ultrasound may be indirect; integrate with unilateral edema, advanced CEAP and thrombosis history.
Venous ratio >2.5, collaterals, thrombus, absent flow or occluded stent	Red	Suggests significant iliocaval obstruction; consider CT venography, MR venography, venography or intravascular ultrasound depending on scenario.

May-Thurner/left common iliac vein compression may be underestimated on transabdominal ultrasound; do not exclude it if clinical suspicion is high.

Source: JVS Venous 2016 / ESVS 2022 / ACR venous guidance / Labropoulos

Post aortic/iliac repair — critical points

Scenario	Color	What to document
Sac stable or shrinking, no endoleak	Green	Maximum sac diameter, iliac limb patency and velocities without focal jet.
Type II endoleak without sac growth	Yellow	Probable location, sac flow and comparison with prior examinations; follow local protocol.
Type I/III endoleak, growth ≥5 mm, limb no-flow or migration	Red	Communicate as potentially relevant complication and suggest correlation with CT angiography/vascular service.

Source: SVU aortoiliac duplex / ACC-AHA 2022 / SVS

Vascular Doppler

Measurements and reference values

Measurement	Usual value	Note
Venous reflux — pathologic duration	> 0,5 s	superficial and deep (femoropopliteal may use > 1 s)
DVT — main criterion	—	non-compressible vein (+ absent flow/filling)

Classifications and calculators

Internal carotid stenosis — SRU 2003

Grade	PSV (cm/s)	EDV (cm/s)	ICA/CCA ratio
Normal	< 125	< 40	< 2,0
< 50%	< 125	< 40	< 2,0
50–69%	125–230	40–100	2,0–4,0
≥ 70%	> 230	> 100	> 4,0
Near occlusion	variable	—	—
Occlusion	no flow	—	—

IAC 2023 update raised the 50% threshold to PSV > 180 cm/s and added a distinct Normal category — check your lab's adopted standard.

Source: SRU Consensus 2003 (Radiology) / Radiopaedia

CEAP — clinical classification (venous)

Class	Clinical finding
C0	No visible/palpable signs
C1	Telangiectasias / reticular veins
C2	Varicose veins
C3	Edema
C4	Skin changes (pigmentation, eczema, lipodermatosclerosis)
C5	Healed ulcer
C6	Active ulcer

Source: CEAP (StatPearls)

Breast

The BI-RADS category should remain internationally standardized. Screening, recall, biopsy and follow-up pathways should follow local policy: ACR/United States, CBR/SBM/FEBRASGO in Brazil, EUSOBI/ESR in Europe and equivalent national guidance. With a palpable finding or clinical discordance, management should not be downgraded by negative imaging alone.

Measurements and reference values

Measurement	Usual value	Note
Minimum exam coverage	breasts and axillae when indicated	In Brazil, CBR/SBM/FEBRASGO recommend axillary extension when there is a nodule or suspicious lesion; billing/coding may be separate.complete: breasts documented and axilla evaluated when indicatedacceptable focused exam: focused request with clinical area clearly documentedincomplete: laterality, symptomatic area or indicated axilla not documented
Location of a focal finding	laterality + clock-face position + distance from nipple	For learners, prefer full wording: right breast, 10 o’clock, 35 mm from the nipple.well localized: laterality, clock-face and distanceacceptable in screening: quadrant/region when there is no focal lesionambiguous: no laterality or no relation to palpable area
Mass measurements	3 dimensions in 2 orthogonal planes	Record the largest axis and the plane used; millimetres improve consistency in structured reporting.ideal: three measurements and two planespartial: two measurements when the third is not obtainedinsufficient: no measurement or no plane/location
Background echotexture	fatty, fibroglandular or heterogeneous	Affects lesion conspicuity and should be reported in screening/supplemental ultrasound.described: composition/echotexture documentedcontextual: omitted in a simple focused examlimits interpretation: supplemental screening without echotexture

Classifications and calculators

Quick assistant — ultrasound BI-RADS

Output	Color	Interpretation
BI-RADS 1–2	Green	Consensus normality/benignity when there is no clinical discordance.
BI-RADS 0 ou 3	Yellow	Incomplete assessment, probable benignity or a zone where guidelines may vary.
BI-RADS 4A–4C, 5 ou 6	Red	Suspicious, highly suspicious or biopsy-proven malignancy; usually requires tissue diagnosis or oncology pathway.

Use the assistant as a descriptor checklist. The final category should reflect the most suspicious finding and clinical-imaging concordance.

Source: ACR BI-RADS v2025 / RANZCR SBIR 2023 / StatPearls

ACR BI-RADS — detailed categories for ultrasound

Category	Color	Meaning / management	Risk
0	Yellow	Incomplete: needs additional imaging, comparison or diagnostic evaluation.	—
1	Green	Negative: routine pathway according to age, risk and local policy.	no suspicious finding
2	Green	Benign: simple cyst, typical intramammary node, stable post-operative finding or equivalent.	essentially benign
3	Yellow	Probably benign: short-interval follow-up, often 6 months, if clinical and imaging findings agree.	< 2%
4A	Red	Low suspicion: tissue diagnosis is generally indicated.	> 2–10%
4B	Red	Moderate suspicion: tissue diagnosis is indicated.	> 10–50%
4C	Red	High suspicion, but not yet classic for category 5.	> 50–< 95%
5	Red	Highly suggestive of malignancy: biopsy and oncology planning.	> 95%
6	Red	Biopsy-proven malignancy before definitive treatment.	confirmed

Category 3 should not be used for “doubt”. If there is relevant diagnostic uncertainty, clinical discordance or a suspicious finding, consider category 0 or 4 depending on the scenario.

Source: ACR BI-RADS v2025 / RANZCR SBIR 2023 / StatPearls

Ultrasound BI-RADS lexicon — mass descriptors

Descriptor	Green	Yellow	Red
Shape	oval or round if other findings are benign	isolated round shape or incomplete context	irregular
Orientation	parallel to skin	not described or difficult to assess	not parallel, taller than wide
Margin	circumscribed	indistinct in a possibly benign context	angular, microlobulated or spiculated
Echo pattern	anechoic typical of a simple cyst	isolated hypoechoic or heterogeneous	complex cystic-solid or suspicious solid
Posterior feature	posterior enhancement in a simple cyst	isolated shadowing may occur in benign findings	shadowing with suspicious margin/shape
Echogenic foci and calcifications	clearly benign macrocalcification	best correlated with mammography	foci within the mass or correlated suspicious calcifications
Associated findings	absent	explainable postoperative/inflammatory changes	distortion, skin/nipple retraction, edema or abnormal axillary node
Elasticity	soft as an adjunct finding	intermediate or heterogeneous	stiff as an adjunct finding; does not replace B-mode

The row color reflects the worst listed finding; combine descriptors, comparison with prior exams and indication.

Source: ACR BI-RADS v2025 ultrasound lexicon / Radiology Assistant summary / RANZCR SBIR

Technical protocol — breast and axilla

Situation	What to document	Color
Screening or complete bilateral exam	Quadrants, retroareolar region, composition/echotexture and axillae when indicated.	Green if complete
Focused exam	Document the exact complaint, laterality, position and relation to the palpable finding.	Yellow if justified
Focal finding	Two orthogonal projections, three measurements, laterality, clock-face position, distance from nipple and transducer orientation.	Red if incomplete in a suspicious lesion
Palpable mass with negative imaging	Apply clinical concordance: lack of imaging finding does not exclude biopsy if clinical concern is suspicious.	Yellow/red by clinical concern
Abnormal axillary node	Treat as a significant lesion: side, level/region, morphology, cortex, hilum, vascularity and associated breast lesion if present.	Red if suspicious

Source: ACR whole-breast ultrasound parameter / CBR-SBM-FEBRASGO / RANZCR SBIR

International and regional standards

Region	Practical standard	App application
Global / ACR	BI-RADS v2025 standardizes terminology, structure, categories and recommendations for mammography, ultrasound, MRI and contrast-enhanced mammography.	Use BI-RADS as the common core.
Brazil	Ultrasound is complementary to mammography after age 40 when indicated; before age 30 it is commonly the initial exam for a clinical abnormality. Axillae may require separate request/coding.	Show regional note and avoid omitting indicated axilla.
Europe / EUSOBI-ESR	Uses BI-RADS as common language; screening may be adjusted by density and risk, with specific recommendations for extremely dense breasts.	Keep BI-RADS category separate from local screening policy.
Australia and New Zealand / RANZCR	BI-RADS-based synoptic report, lesion by lesion, with clinical correlation and management recommendation.	Emphasize laterality, distance from nipple, three measurements and clinical concordance.
Other represented countries	When national policy differs, keep the BI-RADS category standardized and adapt only screening, recall, biopsy and follow-up interval.	Do not invent consensus where guidance diverges.

Source: ACR BI-RADS v2025 / CBR-SBM-FEBRASGO / EUSOBI-ESR / RANZCR SBIR / ACR Appropriateness Criteria

BI-RADS summary — breast ultrasound

Category	Meaning / management	Malig. risk
0	Incomplete — needs mammography, MRI, comparison or repeat evaluation	—
1	Negative — routine screening	0%
2	Benign finding	0%
3	Probably benign — 6-month follow-up	< 2%
4	Suspicious — biopsy (4A 2–10% · 4B 10–50% · 4C 50–95%)	2–95%
5	Highly suggestive — biopsy	> 95%
6	Biopsy-proven malignancy	—

Source: ACR BI-RADS / StatPearls

Teaching summary — suspicious signs in a breast mass

Feature	Suspicious finding
Orientation	Not parallel (taller-than-wide)
Margins	Spiculated, angular, microlobulated
Shape	Irregular
Posterior features	Acoustic shadowing
Echo/foci	Markedly hypoechoic; microcalcifications

Source: ACR BI-RADS US léxico

Axillae

Interpret the axilla by context: palpable lump, suspicious breast finding, oncologic staging, postoperative setting, recent vaccination, skin infection or soft-tissue mass. ACR rates axillary ultrasound as usually appropriate for a palpable axillary lump and many breast-cancer scenarios; EUSOBI treats post-vaccine adenopathy as contextual when ipsilateral, recent and without suspicious breast imaging.

Measurements and reference values

Measurement	Usual value	Note
Minimum axillary protocol	high-frequency linear transducer; side, palpable area, skin, subcutaneous tissue, accessory breast tissue, lymph nodes and vessels when relevant	In breast/oncology context, document the axillary level when possible: lateral to pectoralis minor, posterior to pectoralis minor or medial to pectoralis minor.complete: side, location, morphology and Doppler when indicatedacceptable focused exam: symptomatic area only, with limitation clearly describedincomplete: palpable lump or oncology context without nodal/correlated breast assessment
Typical normal axillary lymph node	oval or gently lobulated, thin homogeneous cortex, preserved fatty hilum	Cortex thinner than 3 mm with a central echogenic hilum is the most used normal pattern; size alone is less reliable than morphology.consensus normal: cortex <3 mm, preserved hilum, oval shapeborderline: cortex 3-5 mm, diffuse and with preserved hilumconsensus abnormal: absent/replaced hilum, eccentric focal cortex or suspicious rounded shape
Lymph-node cortex	<3 normal; 3-5 gray zone; >5 suspicious if there is no clear reactive explanation mm	Some studies use 2.3-3 mm thresholds for sensitivity, but this increases false positives. The table therefore keeps isolated thickening with preserved hilum in yellow.normal: <3 mmgray zone: 3–5 mmsuspicious: >5 mm ou espessamento excêntrico
Lymph-node shape	long-axis/short-axis ratio ≥2 favors benignity; <2 suggests rounding	Avoid abbreviations in learner-facing reports: write long axis and short axis. Round shape carries more weight when paired with hilum loss or eccentric cortex.oval: ratio ≥2indeterminate: ratio near 2 with preserved hilumrounded: ratio <2 with associated suspicious findings
Lymph-node Doppler	hilar/central flow is more reassuring; peripheral, mixed or chaotic flow increases suspicion	Doppler is adjunctive: absent flow does not exclude disease, and hyperemia can be reactive with vaccination, infection or hidradenitis.hilar or absent: compatible if morphology is benignreactive increase: central/hilar in an inflammatory contextperipheral/disorganized: especially with lost hilum or suspicious breast mass
Accessory axillary breast tissue	echotexture similar to breast, may contain cysts, fibroadenoma or malignancy like ordinary breast tissue	If there is a true focal lesion in accessory breast tissue, describe it with the breast lexicon and BI-RADS category according to local context.typical accessory tissue: no focal massprobably benign finding: simple cyst or typical fibroadenomasuspicious lesion: irregular mass, not parallel, suspicious calcifications or skin retraction
Hidradenitis, abscess and axillary skin	dermal thickening, tracts/tunnels, collections, debris and peripheral hyperemia	Ultrasound helps separate lymph node, drainable abscess, skin fistula, epidermal cyst and cellulitis. Gas, deep collection or systemic signs increase urgency.normal skin: no collection or tractinflammatory: thickening, hyperemia or superficial tractcomplicated: drainable abscess, gas, deep collection or immunosuppression

Classifications and calculators

Quick assistant — axillary lymph node

Output	Color	Interpretation
Typical normal	Green	Oval, preserved fatty hilum, cortex <3 mm and hilar/absent flow.
Reactive/indeterminate	Yellow	Cortex 3-5 mm, diffuse thickening with preserved hilum, recent vaccination/infection or incomplete context.
Suspicious	Red	Absent/replaced hilum, eccentric focal cortex, round shape, peripheral/chaotic flow or associated breast/oncology finding.

The output is a teaching triage, not a replacement for BI-RADS, local oncology protocol or biopsy decision.

Source: ACR Imaging of the Axilla / Bedi AJR 2008 / EUSOBI 2023

Bedi-like morphologic classification — teaching version

Type	Color	Morphology	Practical reading
1	Green	No visible cortex or extremely thin cortex	Typical benign if context agrees.
2	Green	Thin cortex up to 3 mm, preserved hilum	Consensus normal.
3	Yellow	Diffuse cortical thickening, usually >3 mm, preserved hilum	May be reactive; compare side, vaccination, skin and breast.
4	Yellow	Lobulated or focal cortical thickening with hilum still identifiable	More concerning than type 3; depends on context and biopsy access.
5	Red	Prominent focal cortex or marked partial hilum replacement	Suspicious, especially in breast cancer or melanoma.
6	Red	Absent/replaced hilum, rounded node or nodal mass	Consensus morphologic abnormality.

Publications vary: some group types 1-4 as benign and 5-6 as suspicious; in this reference type 4 is yellow because it is a decision zone.

Source: Bedi et al. AJR 2008 / axillary node reviews

Clinical context — when to raise the color

Scenario	Suggested color	How to use in the report
No breast finding, no prior cancer, typical nodes	Green	Describe as usual-appearing lymph nodes if the symptom area was covered.
Recent vaccine or ipsilateral skin infection, no suspicious breast finding	Yellow	Report as probably reactive when morphology is not frankly suspicious; follow local policy.
Postoperative setting, lymphedema or radiotherapy	Yellow	Compare with prior studies and document scar/seroma/sentinel-node change if applicable.
Suspicious breast finding or known breast cancer	Red	Describe side, axillary level, cortex, hilum, shape, Doppler and consider sampling according to protocol.
Melanoma, lymphoma, known metastasis or non-nodal solid mass	Red	Do not close as reactive without correlation; may need biopsy, MRI or CT according to the hypothesis.

Source: ACR Appropriateness Criteria / EUSOBI vaccination guidance / oncologic axilla reviews

Differential diagnosis of an axillary mass

Ultrasound pattern	Possibilities	Warning
Tissue with breast-like echotexture, no focal mass	Accessory breast tissue	Green only if there is no focal lesion.
Superficial collection with debris or peripheral hyperemia	Abscess, hidradenitis, inflamed epidermal cyst	Red if gas, deep collection, fever or immunosuppression.
Compressible superficial fatty lesion	Lipoma, accessory fat, rare hernia	Yellow if deep, painful, growing or not fully seen.
Non-fatty solid mass or infiltrative margin	Metastasis, lymphoma, nerve-sheath tumor, sarcoma, advanced skin lesion	Requires correlation and planned imaging/sampling.
Vascular, pulsatile or compressible lesion with flow	Varix, vascular malformation, pseudoaneurysm, fistula	Color and spectral Doppler before puncture.

Source: ACR Imaging of the Axilla / soft-tissue ultrasound reviews

Report checklist — axillae

Item	Write clearly
Side and location	Right/left axilla; palpable area; axillary level when relevant; relationship to scar or skin.
Lymph node	Long axis, short axis, cortical thickness, fatty hilum, shape, margins and Doppler.
Breast context	Whether there is suspicious breast lesion, prior surgery, radiotherapy, lymphedema, recent vaccine or skin infection.
Non-nodal mass	Anatomic layer, content, vascularity, relationship to skin/fascia/vessels and whether it was fully seen.
Conclusion	Use abbreviation-free wording: typical normal, probably reactive, indeterminate or suspicious; state the local next step.

Source: ACR / BI-RADS reporting principles / EUSOBI

Pelvic / transvaginal

Female pelvis combines adult, transvaginal, intrauterine-device, fibroid and pubertal follow-up protocols. In adults, document route, bladder status, limitations, local consent, endometrium, myometrium, cervix, ovaries, adnexa and cul-de-sac. When an intrauterine device or fibroid is present, describe its relationship to the fundus, endometrial cavity, myometrium and serosa.

Measurements and reference values

Measurement	Usual value	Note
Prepubertal uterus — length and thickness	<4,0–4,5 cm	thickness usually <1 cm; length ≤3.2 cm lowers the probability of precocious puberty in referred girlsrobust prepubertal: ≤3.2 cm and thickness ≤1 cmgray zone: >3.2–4.5 cm or thickness 1–1.5 cmabnormal in context: >4.5 cm or thickness >1.5 cm under age 8
Pubertal uterus — configuration	5–8 cm	uterine fundus becomes larger than the cervix; the fundus/cervix ratio alone overlaps between groupstubular: fundus/cervix ≤1transition: 1–1,45early pubertal if <8 years: >1.45 or 2:1–3:1
Ovary — volume in pubertal follow-up	<1–3.5 prepubertal; >3.5–4 suggests stimulation cm³	there is substantial overlap; interpret with uterus, symmetry and clinical stagelow: ≤1 cm³divergent: >1–3,5 cm³pubertal if <8 years: >3,5–4 cm³investigate mass/cyst: >20 cm³
Ovarian follicles and cysts	<4 microcysts; 4–9 follicles; >9 macrocystic mm	small follicles may be physiologic; a dominant unilateral cyst changes interpretationusual childhood: <4 mmpubertal transition: 4–9 mmcontextual macrocystic: >9–20 mmdominant/pathologic: >20 mm
Endometrium and uterine artery Doppler	prepubertal: non-visible endometrium and no diastolic flow	Doppler is complementary and pulsatility-index cutoffs vary widelyprepubertal: no endometrium and no diastolic flowtransition: thin line or intermittent diastoleestrogenization if <8 years: cyclic endometrium or continuous diastole
Adult pelvis — preparation and route	transabdominal with bladder filled if needed; transvaginal with bladder preferably empty	more than one route may be necessary; transrectal or transperineal route is an alternative when transvaginal scanning is not appropriatecomplete documentation: route, bladder, uterus, endometrium, ovaries, adnexa and cul-de-sactechnical limitation: endometrium or ovary not adequately seenmanagement-changing finding: solid mass, torsion, infection, postmenopausal bleeding or extrauterine device
Adult uterus — orienting measurements	length 6–10; thickness 3–5; width 4–6 cm	varies with age, parity, cycle, fibroids, adenomyosis and technique; describe shape, orientation and volume when usefulusual in adults: no mass or cavity distortionenlarged/contextual: parity, fibroids or adenomyosis may explain italert: postmenopausal growth, atypical mass or necrosis
Endometrium — reproductive age	thin during menses; proliferative 4–8; secretory 7–14(16) mm	do not use one cutoff without cycle phase, hormones and focal pattern; measure the thickest part, excluding intracavitary fluidphase-concordant: expected thickness and echotextureborderline: unknown phase, hormonal therapy, mild heterogeneityfocal abnormal: polyp/mass, focal vascularity, persistent bleeding
Endometrium — postmenopausal	≤4 if single bleeding episode, low risk and fully seen echo; recurrent bleeding or high risk requires evaluation mm	ACOG 2026 recommends transvaginal ultrasound plus endometrial sampling for most postmenopausal bleeding; incidental thickness without bleeding does not carry the same weightselected low risk: ≤4 mm, well seen echo, single episodegray zone: incidental without bleeding, hormonal therapy, tamoxifen or incomplete echoinvestigate: >4 mm with bleeding, recurrent bleeding or risk factors
Adult ovaries — measurements and follicles	measure in 3 dimensions; follicles up to 25 mm may be physiologic in reproductive age	after menopause ovaries may not be identified; solid mass, papillary projections, thick septa, ascites or suspicious vascularity change interpretationphysiologic: simple follicle compatible with the cyclefollow-up/context: larger simple cyst or nonvisualized ovary in the right contextsuspicious: solid component, papillary projections, ascites, torsion or postmenopausal mass
Intrauterine device — ideal position	central stem, open arms, top near the fundus/cavity; 3D helps see arms and orientation	there is no universal low-lying definition; studies use >3–4 mm, >5 mm or >20 mm from the fundus, so color depends on location, symptoms and device typeadequate: fundal, central, arms opensupracervical low-lying: above the internal cervical os, especially if asymptomaticmalpositioned: cervical/partially expelled, embedded, perforated, extrauterine, arm not open
Fibroids — minimum documentation	number, location, relationship to cavity, largest lesion in ≥2 dimensions and FIGO 0–8 when possible	3D, sonohysterography or MRI may help differentiate FIGO 2 from FIGO 3 and map hybrid fibroidsno fibroid: myometrium without focal noduleintramural/subserosal: FIGO 3–8 depending on symptoms and sizecavity or suspicion: FIGO 0–2, cavity distortion, postmenopausal growth or atypical morphology

Classifications and calculators

Calculator — O-RADS US v2022 (adnexal mass)

Category	Malignancy risk	Usual management
O-RADS 1	n/a (normal ovary)	No follow-up.
O-RADS 2	<1%	Almost certainly benign; follow-up only per type/size.
O-RADS 3	1–<10%	Low risk; specialist US or follow-up.
O-RADS 4	10–<50%	Intermediate; MRI or gynecologic oncology.
O-RADS 5	≥50%	High risk; gynecologic oncology referral.

Requires a standardized exam (transvaginal, cycle timing). Classic benign lesions (hemorrhagic, endometrioma, dermoid) have their own rules. The color score (flow 1–4) raises the category in multilocular and solid lesions.

Source: ACR O-RADS US v2022 (Radiology 2022)

Calculator — IOTA Simple Rules

Rule	Interpretation
Only B features	Benign.
Only M features	Malignant.
B and M, or none	Inconclusive (~20%): use expert examiner or the ADNEX model.

B: unilocular; solid <7 mm; acoustic shadows; smooth multilocular <10 cm; no flow. M: irregular solid; ascites; ≥4 papillae; irregular multilocular-solid ≥10 cm; strong flow.

Source: IOTA Simple Rules — Timmerman, Ultrasound Obstet Gynecol 2008/2016

Interactive calculator — FIGO 0–8 fibroids

Input	How to use	Limitation
No focal fibroid	Use when the myometrium has no defined leiomyomatous nodule.	Does not exclude diffuse adenomyosis or subtle myometrial abnormality.
FIGO 0–2	Submucosal or intracavitary: greater impact on bleeding, fertility and hysteroscopic planning.	Differentiating FIGO 2 from FIGO 3 may require 3D, sonohysterography or hysteroscopy.
FIGO 3–8	Maps contact with endometrium, myometrium and serosa; color depends on symptoms, size, growth and morphology.	The classification is anatomical: it does not replace size, number and vascularity description.

The interactive table below is educational and assistive. The final category must be checked by the physician, especially with multiple, hybrid fibroids, cavity distortion or suspected adenomyosis.

Source: FIGO 2018 PALM-COEIN / Merck Manual / AIUM / MUSA

Adult and transvaginal female pelvis — minimum protocol

Step	What to document	Color
Route and preparation	Transabdominal with bladder filled when it improves the acoustic window; transvaginal with bladder preferably empty.	Green if documented
Uterus and cervix	Size, shape, orientation, myometrium, cervix, endometrium and relevant masses in at least two dimensions.	Green if complete
Incomplete endometrium	If not fully seen or poorly defined, report the limitation and avoid a falsely precise measurement.	Yellow
Ovaries and adnexa	Try to identify ovaries first, measure in three dimensions when needed, and describe masses by composition, septa, papillary projections, vascularity and relationship to uterus/ovary.	Green if complete
Critical finding	Torsion, suspicious solid mass, abscess, perforated/extrauterine device or high-risk postmenopausal bleeding.	Red

Source: AIUM female pelvis parameter / ACR-ACOG-AIUM-SPR-SRU 2024

Intrauterine device — ultrasound location

Finding	Interpretation	Descriptive action
Fundal and central	Stem on the cavity axis, arms open and top near the fundus/cavity.	Describe type if known and whether 3D confirmed the arms.
Low, but above cervix	Divergent zone: there is no universal distance; studies use 3–4 mm, 5 mm or 20 mm.	Report distance to fundus, symptoms, device type and relationship to fibroids/cavity.
Cervical or partially expelled	Higher risk of complete expulsion and contraceptive failure.	Describe component in the cervical canal and suggest gynecologic evaluation.
Embedded, perforated or extrauterine	Arm or stem in the myometrium, through the serosa or outside the cavity.	3D, radiography/CT or hysteroscopy may be needed depending on the case.

Source: AIUM / Connolly-Fox JUM 2021 / JSIM 2024 / Exxcellence 2025

Adult endometrium — context-based reading

Context	Green	Yellow	Red
Reproductive age	Thickness and echotexture compatible with cycle phase.	Unknown phase, hormonal therapy or heterogeneous endometrium without a defined mass.	Focal lesion, focal vascularity or persistent bleeding.
Postmenopausal without bleeding	Thin, regular and well seen endometrium.	Incidental thickness greater than 4 mm is not equivalent to postmenopausal bleeding.	Focal mass, suspicious fluid or important risk factors.
Postmenopausal bleeding	≤4 mm only in a selected low-risk patient, single episode and fully seen echo.	Incomplete echo, hormonal therapy, tamoxifen or barrier to prompt follow-up.	>4 mm, recurrent bleeding or high risk; ACOG 2026 favors sampling in most patients.

Source: AIUM / ACOG Committee Opinion 2018 / ACOG Clinical Practice Update 2026

Fibroids — FIGO 0–8 classification

Type	Anatomic relationship	Practical reading
No fibroid	Myometrium without a defined leiomyomatous nodule.	Green: consensus normality for focal fibroid.
FIGO 0	Pedunculated intracavitary.	Red: submucosal, usually relevant for bleeding and hysteroscopy.
FIGO 1	Submucosal with less than 50% intramural.	Red: distorts the cavity; measure base and intramural component.
FIGO 2	Submucosal with 50% or more intramural.	Red: planning depends on myometrial extension.
FIGO 3	100% intramural, contacting the endometrium.	Yellow: differentiating from FIGO 2 may require 3D or sonohysterography.
FIGO 4	Pure intramural.	Yellow: impact depends on size, symptoms and distortion.
FIGO 5	Subserosal with 50% or more intramural.	Yellow: map serosa, wall and mass effect.
FIGO 6	Subserosal with less than 50% intramural.	Yellow: confirm uterine origin.
FIGO 7	Pedunculated subserosal.	Yellow: pedicle Doppler helps differentiate from adnexal mass.
FIGO 8	Other: cervical, parasitic, ligamentary or special location.	Yellow: specify location.
Hybrid	Two numbers separated by a hyphen; first endometrium, second serosa.	Example 2-5: submucosal and subserosal with measurable components.

FIGO is anatomical and alone does not include size, number, degeneration, vascularity or sarcoma suspicion. These elements should be reported when relevant.

Source: FIGO PALM-COEIN 2018 / Merck Manual / AIUM / MUSA

Calculator — pubertal maturation from female pelvis ultrasound

Input	How the app interprets it	Limitation
Uterine measurements	Length, thickness, width and fundus/cervix ratio estimate estrogenization.	They do not define precocious puberty alone.
Ovarian volumes	They help when combined with uterus, follicles and symmetry.	There is overlap between prepubertal and early pubertal states.
Endometrium and Doppler	Visible endometrium and continuous diastolic flow suggest estrogenization.	They are complementary markers, not single criteria.

Use as a teaching aid. The conclusion must integrate Tanner stage, growth curve, bone age, hormones and endocrine assessment.

Source: Frontiers Endocrinol 2021 / Pediatric Radiology 2024 / ACR-AIUM-SPR-SRU female pelvis parameter

Pubertal maturation — ultrasound signs

Marker	Green	Yellow	Red
Uterine length	≤3,2 cm	>3,2–4,5 cm	>4.5 cm under age 8
Uterine configuration	tubular; fundus/cervix ≤1	fundus/cervix 1–1.45	dominant fundus, 2:1–3:1 in early context
Ovarian volume	≤1 cm³	>1–3,5 cm³	>3.5–4 cm³ under age 8; >20 cm³ investigate
Follicles/cysts	<4 mm	4–20 mm	>20 mm or dominant unilateral lesion
Endometrium	not visible	thin line	cyclic/thickened under age 8
Uterine Doppler	no diastole	intermittent diastole	continuous diastole under age 8

Source: StatPearls 2025 / Radiologia Brasileira / Pediatric Radiology 2024

Precocious puberty versus premature thelarche or pubarche — practical reading

Situation	Reading	Next step
Pubertal signs before age 8	Yellow: alert clinical context.	Correlate with Tanner stage, growth velocity, bone age and hormones.
Uterus >3.2 cm	Raises probability in referred girls, but is not diagnostic.	Compare with uterine volume/configuration and laboratory tests.
Uterus >4.5 cm or pubertal shape under age 8	Red: strong evidence of early estrogenization.	Refer/coordinate with pediatric endocrinology.
Bilaterally enlarged ovaries with follicles	Yellow/red depending on age and uterus.	Consider gonadotropic stimulation if uterus is also pubertal.
Dominant unilateral cyst or adrenal/ovarian mass	Red: may suggest peripheral cause or pathology.	Assess adnexa/adrenals and recommend targeted workup.
Small uterus and small ovaries with isolated thelarche	Green/yellow: may support isolated premature thelarche.	Clinical follow-up if progression is slow and tests agree.

Source: Frontiers Endocrinol 2021 / Radiologia Brasileira / Pediatric Radiology 2024

Technical protocol — pediatric and pubertal female pelvis

Step	What to document
Route	Transabdominal with full bladder as standard; endocavitary route only when clinically appropriate, consented and compatible with age/local context.
Clinical context	Age, menarche, breast development, pubic hair, bleeding and growth velocity when provided.
Uterus	Length, thickness, width, volume, fundus/cervix ratio, shape and endometrium.
Ovaries	Three diameters or volume of each ovary, largest follicle/cyst, symmetry and focal lesions.
Doppler	Uterine diastolic flow if assessed; do not use as an isolated criterion.

Source: ACR-AIUM-SPR-SRU practice parameter / StatPearls 2025

International and regional standards — why use color bands

Source/region	Practical message
ACR, AIUM, SPR and SRU	Standardize female pelvis/adnexal documentation and technique, but do not impose one universal pubertal cutoff.
International pediatric radiology	Published cutoffs for uterine length/volume and ovarian volume vary substantially.
Brazilian radiology	Suggests practical prepubertal limits: uterus <4.5 cm, thickness <1 cm and ovary <3 cm³.
Endocrinology	Ultrasound is adjunctive; final diagnosis depends on clinical findings, bone age and hormone testing.

Source: ACR-AIUM-SPR-SRU / Radiologia Brasileira / Frontiers Endocrinol 2021 / Pediatric Radiology 2024

Prostate

Brazil: abdominal prostate/male pelvis ultrasound includes bladder, prostate, seminal vesicles and post-void residual by CBR. Transrectal ultrasound better evaluates the prostate and periprostatic structures, but does not routinely include bladder/PVR.

Measurements and reference values

Measurement	Usual value	Note
Usual adult prostate volume	15–30 mL	increases with age; >30 mL suggests benign enlargement in many guidelinesusual: 15–30 mLmild/contextual enlargement: >30–40 mLenlarged: >40 mLlarge: >80 mL
Prostate volume calculation	largura × espessura × comprimento × 0,52	ellipsoid formula; g and mL are used almost interchangeably for planning
PSA density	PSA ÷ volume ng/mL/cm³	interpretation depends on age, digital rectal exam, family history and MRIstrong low risk: <0,10low by classic cutoff: 0,10–0,15suspicious/borderline: 0,15–0,20elevated: ≥0,20
Intravesical prostatic protrusion	<5 mm	measure from bladder base to the tip of the protrusion into the bladder lumengrade I: 0–4,9 mmgrade II: 5–10 mmgrade III: >10 mm
Seminal vesicles — anteroposterior diameter	<15 mm	mainly in transrectal/infertility evaluation; >15 mm suggests dilatationusual: <15 mmborderline: 15–20 mmdilated: >20 mm

Classifications and calculators

Calculator — prostate volume, PSA density and intravesical protrusion

Input	Calculation	How to interpret
Volume	largura × espessura × comprimento × 0,52	15–30 mL is commonly the usual adult range.
PSA density	PSA ÷ volume	0.10–0.20 is context-dependent on MRI, age, digital rectal exam and family history.
Intravesical protrusion	distance in mm into bladder lumen	>10 mm is ICS grade III and suggests higher obstruction likelihood.

Assistive calculator: it does not replace serial PSA, digital rectal exam, MRI, urinary symptoms and urologic assessment.

Source: AIUM / AUA benign prostate enlargement / EAU prostate cancer / ICS

Prostate size — benign enlargement planning

Range	Reading	Practical use
<30 mL	Small / usual	Below classic benign enlargement cutoff.
30–40 mL	Mild enlargement	Above 30 mL, but progression depends on symptoms, PSA and residual.
>40–80 mL	Enlarged	EAU uses >40 mL as an example of higher progression risk for considering 5-alpha-reductase inhibitors.
>80–150 mL	Large	Important category for surgical technique selection.
>150 mL	Very large	AUA category for treatment planning.

Source: AUA benign prostate enlargement guideline / EAU male urinary symptoms

Intravesical prostatic protrusion — ICS

Grade	Measure	Interpretation
I	0–4,9 mm	Small protrusion.
II	5–10 mm	Intermediate; correlate with urinary flow and residual.
III	>10 mm	Associated with higher chance of bladder outlet obstruction.

Source: International Continence Society glossary

Scrotum / testis with Doppler

Scrotal ultrasound should always answer three questions: is there a vascular/infectious emergency, is there an intra- or extratesticular mass, and is there varicocele/reflux affecting volume or fertility. In acute pain, comparative intratesticular Doppler and active search for a twisted cord are central parts of the exam.

Measurements and reference values

Measurement	Usual value	Note
Minimum protocol	bilateral + comparative + Doppler when indicated	Measure both testes in three axes; assess epididymides, tunics, fluid, scrotal wall, spermatic cord and inguinal canal if pain, mass, hernia or varicocele are suspected.
Transducer and Doppler	linear ≥12 MHz; Doppler optimized for low flow	Adjust scale, wall filter and gain to detect slow intratesticular flow; always compare with the contralateral side in acute pain.
Testis — adult volume by ellipsoid	length × width × height × 0.52 mL	Ranges vary by population. Use green for 15-25 mL, yellow for 10-14.9 mL or contextual >25 mL, red for <10 mL in adults/postpubertal patients when technique is reliable.usual adult range: 15–25 mLlow-normal / borderline: 10–14,9 mLreduced: <10 mL
Volume in varicocele — Lambert formula	length × width × height × 0.71 mL	ESUR-SPIWG prefers Lambert for varicocele assessment and recommends reporting which formula was used.
Testicular asymmetry	<20 %	A difference ≥20% is an important yellow zone in adolescents/varicocele; it affects follow-up and clinical decision-making.
Epididymis — head	≤12 mm	An enlarged, hypoechoic and hypervascular head supports epididymitis when painful; isolated enlargement may be cyst/spermatocele.
Varicocele — largest vein standing with Valsalva	≥3 mm	ESUR considers 3 mm or more diagnostic when measured standing during Valsalva, especially with Doppler reflux.usual: <2 mmborderline: 2–2,9 mmvaricocele: ≥3 mm + refluxo
Varicocele — reflux duration	>2 s	The essential parameter is spectral-Doppler reflux duration; ESUR suggests >2 s standing during Valsalva.no pathologic reflux: <1 sgray zone: 1–2 spathologic: >2 s
Isolated testicular microlithiasis	no routine follow-up	Without a solid mass and risk factors, AUA/ESUR do not recommend routine workup or serial ultrasound.

Classifications and calculators

Interactive assistant — scrotum, testes and Doppler

Input	How to interpret	Limitation
Functional normality	Volumes in usual range, symmetric intratesticular flow, no mass, no pathologic reflux and no complication signs.	Always depends on clinical indication and bilateral comparison.
Gray zone	Volume 10-14.9 mL, asymmetry ≥20%, vein 2-2.9 mm, reflux 1-2 s, uncomplicated epididymitis, typical extratesticular lesion or microlithiasis with risk.	Requires context, position, Valsalva and selective follow-up.
Abnormal or urgent	Reduced/absent flow, whirlpool sign, solid intratesticular mass, abscess/pyocele, rupture, complicated hernia or recent isolated right varicocele.	Rapid clinical communication may be required.

Use as educational triage. Torsion may retain some residual flow; a solid intratesticular mass should be treated as malignant until proven otherwise.

Source: AIUM-ACR-SPR-SRU 2025 / ACR acute scrotum / AUA testicular cancer / ESUR-SPIWG

Varicocele — ESUR-SPIWG documentation

Item	Report	Color
No varicocele	Veins <2 mm, no pathologic reflux and no relevant asymmetry.	Green
Borderline/subclinical	Vein 2-2.9 mm, short reflux or finding in only one position.	Yellow
Ultrasound varicocele	Largest vein ≥3 mm standing with Valsalva and reflux >2 s on spectral Doppler.	Red: consensus abnormal.
Adolescent or infertility	Measure both testicular volumes and asymmetry; report the formula used.	Yellow if no atrophy; red if marked atrophy.
Isolated right-sided or recent onset	Consider abdominal/renal extension, especially if it does not reduce supine.	Red because secondary causes must not be missed.

Report position, vein level, diameter, Valsalva, reflux duration and whether standing and supine positions were assessed.

Source: ESUR-SPIWG / Royal College of Radiologists audit template / EAU Paediatric Urology

Acute scrotum — Doppler and critical signs

Finding	Interpretation	Reporting action
Absent or reduced intratesticular flow	Torsion or ischemia until proven otherwise.	Urgent communication.
Whirlpool sign in the cord	Direct sign of torsion, including partial/intermittent torsion.	Describe knot location and residual flow.
Epididymal/testicular hyperemia	Favors epididymitis, orchitis or epididymo-orchitis.	Look for abscess, pyocele and infarction.
Abscess, pyocele, necrosis or infarction	Relevant infectious/vascular complication.	Communicate and suggest urologic correlation.
Trauma with tunica rupture	Risk of testicular loss if delayed.	Describe discontinuity, hematoma and Doppler viability.

Source: ACR acute scrotum / AIUM-ACR-SPR-SRU 2025 / BMUS acute epididymo-orchitis complications

Masses, cysts and microlithiasis

Pattern	Interpretation	Comment
Simple intratesticular or tunica cyst	Anechoic, thin wall, posterior enhancement, no solid component and no flow.	Green if all typical criteria are present.
Solid intratesticular mass	Manage as malignant until proven otherwise.	AUA: tumor markers before treatment; Doppler helps, but absent flow does not exclude tumor.
Typical extratesticular lesion	Epididymal cyst, spermatocele, appendage, lipoma or adenomatoid tumor may be benign.	Describe origin and relationship to epididymis, cord and tunics.
Solid extratesticular mass	More often benign than intratesticular, but not automatically benign.	Consider MRI/referral if indeterminate.
Isolated microlithiasis	No mass and no risk factors: no routine follow-up required.	AUA/ESUR guidance.
Microlithiasis with risk factor	Cryptorchidism/orchidopexy, personal/family history of germ-cell tumor, atrophy or infertility.	Individualized follow-up.

Source: AUA testicular cancer guideline / ESUR microlithiasis guideline / ACR palpable scrotal abnormality

Main differentials

Condition	Useful findings	Pitfall
Testicular torsion	Reduced/absent flow, cord whirlpool, high-riding or horizontal testis, reactive edema.	Residual flow may persist in partial torsion.
Torsion of testicular appendage	Small avascular nodule near upper pole, peripheral reactive hyperemia.	May mimic epididymitis.
Epididymitis/orchitis	Enlarged epididymis, hyperemia, reactive hydrocele and skin thickening.	Infarction/abscess makes it red.
Testicular tumor	Solid intratesticular mass, usually hypoechoic and vascular; calcification/scar may indicate burned-out tumor.	Do not routinely biopsy through the scrotum.
Hydrocele, hematocele or pyocele	Simple fluid, internal echoes, septa, debris, clots or gas depending on etiology.	Complex pyocele/hematocele with symptoms changes urgency.
Inguinoscrotal hernia	Fat or bowel content, peristalsis, Valsalva and reducibility.	Nonreducible bowel or ischemia is urgent.

Source: AIUM-ACR-SPR-SRU / ACR acute scrotum / AUA / ESUR

Penis / penile Doppler

Penile ultrasound does not have a single universal system like TI-RADS or BI-RADS. Safety comes from separating the clinical question: trauma, plaque/fibrosis, priapism, superficial venous thrombosis, mass/infection, or vascular erectile dysfunction. In dynamic Doppler, thresholds vary: European guidance accepts peak systolic velocity above 30 cm/s as normal, while radiology reviews use above 35 cm/s to exclude significant stenosis. Therefore, 30-35 cm/s is yellow, not absolute green.

Measurements and reference values

Measurement	Usual value	Note
Minimum anatomic protocol	high-frequency linear transducer; transverse and longitudinal planes	Assess corpora cavernosa, corpus spongiosum, glans, penile urethra when relevant, tunica albuginea, deep fascia, cavernosal arteries, dorsal arteries, and superficial/deep dorsal veins according to the clinical question.
Normal B-mode anatomy	two dorsolateral corpora cavernosa + ventral corpus spongiosum	The tunica albuginea appears as a thin echogenic line around the erectile bodies; the cavernosal artery is usually seen in the center of each corpus cavernosum.
Penile fracture	tunica albuginea discontinuity + hematoma	A snap, sudden pain, detumescence, and bruising make the clinical diagnosis likely; ultrasound localizes the tear and measures hematoma. Hematuria, urinary retention, or air in the erectile bodies suggest urethral injury and change urgency.continuous tunica: no deep hematomahematoma with intact tunica: fracture mimic differentiallikely fracture: tunical defect
Peyronie disease — plaque	focal tunical thickening, fibrosis, or calcification	Report location, side, length, thickness, calcification/acoustic shadowing, relationship to septum and neurovascular bundle, curvature during induced erection when performed, and Doppler flow around the plaque if active phase is suspected.noncalcified plaque: may be active phasecalcification: affects treatment planningmass or atypical erosion: do not assume Peyronie
Ischemic priapism	markedly reduced or absent cavernosal flow	This is a urologic emergency, especially with a painful erection lasting more than 4 hours. Doppler should be performed before aspiration when possible, because intervention may create reactive hyperemia and confuse interpretation.emergency: pain + rigidity + little/no flowindeterminate: correlate with corporal blood gas
Nonischemic / high-flow priapism	high/turbulent flow, fistula, or pseudoaneurysm	Often follows perineal/penile trauma and is less painful. It is not the same emergency as ischemic priapism, but it is abnormal and Doppler localizes the fistula for guided compression, follow-up, or embolization.
Superficial dorsal vein thrombosis	noncompressible vein + echogenic thrombus + absent flow	Also called penile Mondor disease. It is usually benign/self-limited, but Doppler helps distinguish it from Peyronie disease, sclerosing lymphangitis, mass, and hematoma.usually self-limited abnormality: confirm compressibility and flowsystemic signs or mass: look for another cause
Dynamic Doppler — technique	measure cavernosal arteries at the base every 5 min up to 20-30 min	Record drug and dose, injection side, time, rigidity grade, peak systolic velocity, end-diastolic velocity, resistive index, and side-to-side difference. Doppler angle should be kept below 60 degrees.
Post-stimulation peak systolic velocity	strong green >35; divergent 30-35; abnormal <25 cm/s	European guidance considers above 30 cm/s usually normal; radiology reviews use above 35 cm/s to exclude significant stenosis. Between 25 and 35 cm/s, interpret as a gray zone with rigidity, dose, anxiety, and timing.strong normality: >35 cm/snormal in some sources: 30–35 cm/sindeterminate: 25–29 cm/slikely arterial insufficiency: <25 cm/s
End-diastolic velocity	<3 by European guidance; >5 suggests venous leak if arterial inflow is adequate cm/s	Veno-occlusive interpretation is reliable only when arterial response and rigidity are sufficient; anxiety and low dose may mimic venous leak.strict normal: <3 cm/sgray zone: 3–5 cm/slikely venous leak: >5 cm/s com boa resposta arterial
Resistive index	>0.8 usually normal	Below 0.8 together with elevated end-diastolic velocity suggests veno-occlusive dysfunction; use cautiously if arterial response was poor.normal: >0,8borderline: 0,75–0,80suspicious: <0,75 ou <0,8 com diástole elevada

Classifications and calculators

Interactive assistant — penis and penile Doppler

Green	Peak systolic velocity above 35 cm/s on both sides, low end-diastolic velocity, resistive index above 0.8, adequate rigidity, and no critical anatomic findings.
Yellow	Peak systolic velocity 25-35 cm/s, diastole 3-5 cm/s, incomplete rigidity, technique without vasoactive injection, plaque/calcification, superficial dorsal thrombosis, or nonischemic priapism.
Red	Peak systolic velocity below 25 cm/s, diastole above 5 cm/s with good arterial inflow, low resistive index, ischemic priapism, high-flow fistula, fracture, suspicious mass, abscess, gas, or urethral sign.

This tool is educational: it does not replace urologic evaluation, corporal blood gas in priapism, or treatment decisions. In prolonged painful priapism or penile fracture, communication should be immediate.

Source: EAU / AUA-SMSNA / RadioGraphics / Radiologia Brasileira

Dynamic Doppler — hemodynamic reading

Parameter	Green	Yellow	Red
Peak systolic velocity	>35 cm/s	25–35 cm/s	<25 cm/s
Cavernosal artery side difference	<10 cm/s	>10 cm/s with preserved velocities	>10 cm/s with lower side <25 cm/s
End-diastolic velocity	<3 cm/s	3–5 cm/s	>5 cm/s persistent if arterial inflow is adequate
Resistive index	>0,8	0,75–0,8	<0.75 or <0.8 with elevated diastole
Rigidity	complete or sufficient rigidity	tumescence or partial rigidity	no response despite adequate technique

Source: EAU Erectile Dysfunction / RadioGraphics 2024 / EPOS ECR 2024

Emergencies and differentials

Condition	Ultrasound findings	Practical message
Penile fracture	Focal tunica albuginea defect, adjacent hematoma, sometimes urethra/corpus spongiosum involved.	Surgical emergency in most cases; localize the tear.
Ischemic priapism	Absent or high-resistance cavernosal flow, rigid and painful corpora cavernosa.	Emergency; do not delay treatment.
High-flow nonischemic priapism	Arteriocavernosal fistula, pseudoaneurysm, turbulence and low-resistance flow.	Usually not ischemic, but abnormal and may need embolization.
Penile Mondor disease	Noncompressible superficial dorsal vein with thrombus and absent flow.	Usually self-limited; distinguish from plaque, mass, and lymphangitis.
Peyronie disease	Tunica albuginea plaque, thickening, fibrosis, calcification, or acoustic shadowing.	Measure and map; Doppler helps if erectile dysfunction is also present.
Deep infection or abscess	Collection, hyperemia, gas, skin/fascial thickening, or perineal extension.	May be an emergency, especially with gas or suspected Fournier disease.
Suspicious mass	Irregular solid lesion, glans/foreskin, local invasion, vascularity, or suspicious nodes.	Do not label as plaque; refer for workup.

Source: Radiologia Brasileira / RadioGraphics / AUA / EAU

Structured report checklist

Block	What to report	Why it matters
Technique	Transducer, planes, ventral/dorsal approach, color/spectral Doppler and Doppler angle.	Avoids wrong measurements from angle or sampling.
Dynamic Doppler	Drug, dose, injection side, timing of measurements and rigidity grade.	Without this, velocity and venous leak can be false.
Plaques/fibrosis	Location by surface/third, size, calcification, shadowing and septal relationship.	Helps urology plan treatment.
Trauma	Tunica integrity, hematoma, corpus spongiosum, urethra and cavernosal vascularity.	Defines urgency and surgical map.
Priapism	Ischemic versus nonischemic, cavernosal flow, fistula/pseudoaneurysm and whether it was before aspiration.	Completely changes management.

Source: EAU / AUA-SMSNA / RadioGraphics

Obstetric — 1st trimester

Measurements and reference values

Measurement	Usual value	Note
Gestational sac visible (TV)	≈ 5,0 wk	2–3 mm sac
Yolk sac visible	MSD ≤ 10 mm	≈ 5.5–6 wk
Embryo with heartbeat	≈ 6 wk	usually by MSD 25 mm
Embryonic HR — poor prognosis	< 90 bpm	in embryo < 8 wk

Classifications and calculators

Calculator — nuchal translucency (11–13+6 wk)

NT	Reading
< 3.0 mm (CRL 45–84 mm)	Within expected; integrate into combined risk.
3,0–3,4 mm	Above the 95th percentile for most CRLs; weigh in risk.
≥ 3,5 mm	Increased risk (aneuploidy, cardiac, syndromes): counseling + diagnostic testing + fetal echo.

Only measure in the CRL 45–84 mm window, mid-sagittal plane, neutral fetus, adequate magnification. Secondary markers: absent nasal bone, tricuspid regurgitation, ductus venosus reversed a-wave.

Source: Fetal Medicine Foundation (FMF) / ISUOG guidelines

Criteria for NONVIABLE pregnancy (2012 consensus)

Finding	Conclusion
CRL ≥ 7 mm with NO heartbeat	Nonviable
MSD ≥ 25 mm with NO embryo	Nonviable
No embryo w/ HB ≥ 2 wk after sac without yolk sac	Nonviable
No embryo w/ HB ≥ 11 days after sac with yolk sac	Nonviable

Diagnostic (definitive) criteria from the 2012 SRU consensus. "Suspicious" findings warrant a follow-up scan.

Source: SRU Consensus 2012 (Doubilet et al.)

Carotid arteries — Doppler / plaque

Brazil: the main reference adopted here is the 2023 DIC/SBC + Brazilian College of Radiology + Brazilian Society of Angiology and Vascular Surgery update, using NASCET grading. United States: IAC 2023 recommends raising the internal carotid systolic velocity threshold to 180 cm/s for 50% stenosis. When standards diverge, the interface marks yellow and names the source.

Measurements and reference values

Measurement	Usual value	Note
Peak systolic velocity — internal carotid artery	<140 in the Brazilian standard for <50% cm/s	IAC 2023 uses <180 cm/s for normal or <50%; 140–179 cm/s is a yellow zone if other parameters do not confirm stenosis.Green — no plaque and low velocity: <125–140 cm/sYellow — SRU/Brazil/IAC divergence: 125–179 cm/sRed — likely hemodynamic stenosis: ≥180 cm/s com placa/razão elevada; >230 cm/s alto grau
End-diastolic velocity — internal carotid artery	<40 cm/s	Helps confirm the stenosis range when systolic velocity is not representative.Green: <40 cm/sRed — 50% or more: ≥40 cm/sRed — high grade: >100 cm/s; >140 cm/s sugere 80–89% no padrão brasileiro
Internal carotid / common carotid systolic ratio	<2,0	Use the highest internal carotid systolic velocity at the stenosis and the common carotid systolic velocity in a representative segment away from plaque.Green: <2,0Red — 50–69%: 2,0–4,0Red — 70% or more: >4,0
Intima-media thickness	≤0,9 mm	Operational cutoff; the Brazilian recommendation prefers age-, sex- and ethnicity-specific percentiles when available and does not recommend routine measurement in the general population.Green — usual: ≤0,9 mmYellow — thickened: >0,9 mmRed — plaque by thickness: >1,5 mm se focal
Carotid plaque — definition	protrusion ≥0.5 mm or >50% of adjacent wall or >1.5 mm	Any one criterion is enough; plaque should not be called only intima-media thickening.Green: no focal protrusionYellow: smooth/calcified plaque without relevant stenosisRed: ulcerated, predominantly echolucent plaque or stenosis ≥50%
Doppler angle for velocities	≤60 degrees	The angle should be corrected and no greater than 60 degrees whenever velocity is measured.

Classifications and calculators

Quick calculator — carotid stenosis by Doppler

Color	Result	How to interpret
Green	No hemodynamically significant stenosis	Low velocities, internal/common ratio <2.0 and no relevant plaque.
Yellow	Borderline or divergent zone	Plaque without relevant stenosis, intima-media thickening, or velocity 125–179 cm/s without confirmation by ratio/plaque.
Red	Abnormal stenosis or high risk	Stenosis of 50% or more, near occlusion, occlusion, ulcerated plaque or predominantly echolucent plaque.

The calculator cross-checks DIC/SBC-CBR-SBACV 2023, IAC 2023 and SRU 2003. The final result must consider technique, Doppler angle, arrhythmia, tandem stenoses, contralateral occlusion and clinical correlation.

Source: DIC/SBC-CBR-SBACV 2023 / IAC 2023 / SRU 2003

Plaque-RADS — carotid plaque morphology classification

Category	Main criterion	Subtype / detail	Color reading
1	No atherosclerotic plaque.	Wall without detectable plaque.	Green — consensus morphologic normality.
2	Plaque present with maximum wall thickness <3 mm.	No intraplaque hemorrhage, cap rupture or intraluminal thrombus.	Yellow — low-risk plaque, but not a normal wall.
3a	Maximum wall or plaque thickness ≥3 mm.	Thick/intact fibrous cap; no complicated feature.	Yellow — intermediate risk.
3b	Maximum thickness ≥3 mm with suspected thin fibrous cap.	Ultrasound may suggest it; MRI better assesses a thin cap.	Yellow — possible vulnerability; confirm in context.
3c	Ulcerated plaque.	Cavity/ulcerated surface communicating with the lumen.	Red — abnormal risk morphology.
4a	Intraplaque hemorrhage.	Complicated feature; ultrasound may be limited.	Red — complicated plaque.
4b	Fibrous cap rupture.	Complicated feature.	Red — complicated plaque.
4c	Intraluminal thrombus.	Complicated feature.	Red — complicated plaque.

Plaque-RADS complements, but does not replace, stenosis percentage. When multiple plaques are present, record the highest category and describe the dominant plaque.

Source: Saba et al., JACC Cardiovascular Imaging 2024 / QIMS 2026 ultrasound validation

Internal carotid stenosis — Brazil 2023 (NASCET)

Stenosis	Internal systolic velocity	Internal diastolic velocity	Internal/common systolic ratio	Comment
<50%	<140	<40	<2,0	Not hemodynamically significant; if plaque is present, describe morphology.
50–59%	140–230	40–69	2,0–3,1	Range where there is divergence from IAC 2023 when systolic velocity is below 180 cm/s.
60–69%	no own cutoff	70–100	3,2–4,0	Use diastolic velocity and ratio as confirmation.
70–79%	>230	>100	>4,0	High-grade stenosis; differentiate from near occlusion.
80–89%	no own cutoff	>140	no own cutoff	Very high diastolic velocity supports high grade.
>90%	>400	no own cutoff	>5,0	Velocity may paradoxically fall if near occlusion is present.
Near occlusion	variable — threadlike flow	variable	variable	Diagnosis is morphologic/color Doppler-based; it does not depend on a fixed cutoff.
Occlusion	absence of flow	absence of flow	not applicable	No detectable patent lumen.

Use the NASCET method for the reported percentage. Systolic velocity is the primary criterion; diastolic velocity and ratios confirm when velocity is affected by hemodynamic factors.

Source: DIC/SBC + CBR + SBACV 2023

IAC 2023 — modified internal carotid criteria

Category	Internal systolic velocity	Plaque estimate	Internal/common systolic ratio	Internal diastolic velocity
Normal	<180	none	<2,0	<40
<50%	<180	<50%	<2,0	<40
50–69%	180–230	>50%	2,0–4,0	40–100
>70% up to before near occlusion	>230	>50%	>4,0	>100
Near occlusion	high, low or undetectable	visible	variable	variable
Total occlusion	undetectable	visible, no detectable lumen	not applicable	not applicable

IAC recognizes that 125–180 cm/s with ratio ≥2.0, significant plaque and post-stenotic turbulence may also be 50–69%.

Source: IAC Vascular Testing Communication 2023

SRU 2003 — classic criterion still found in services

Category	Internal systolic velocity	Internal diastolic velocity	Internal/common systolic ratio
Normal	<125	<40	<2,0
<50%	<125	<40	<2,0
50–69%	125–230	40–100	2,0–4,0
70% or more up to near occlusion	>230	>100	>4,0
Near occlusion	variable	variable	variable
Occlusion	no flow	no flow	not applicable

Kept for historical comparison; when used, state the standard adopted by the service.

Source: SRU Consensus Conference 2003

Plaque morphology and surface

Item	Finding	Color reading
No plaque	No focal protrusion and no focal thickening >1.5 mm.	Green if velocities are normal.
Echogenic or calcified plaque	Type III–V; calcification may cast shadow and limit measurement.	Yellow if no stenosis ≥50%; red if it limits assessment or accompanies stenosis.
Predominantly echolucent plaque	Type I–II; associated with greater vulnerability in several classifications.	Red for morphologic risk.
Irregular surface	Irregularity 0.4 to 2.0 mm deep.	Yellow; describe in the report.
Ulceration	Concavity/extension >2.0 mm by the de Bray criterion.	Red; high morphologic risk.

Plaque-RADS 2024 reinforces that plaque morphology/composition complements stenosis percentage, but does not yet replace hemodynamic grading.

Source: DIC/SBC-CBR-SBACV 2023 / Plaque-RADS 2024

Technical checklist — carotid and vertebral arteries

Step	Record	Reason
Longitudinal B-mode	Intima-media thickness when indicated and plaque at bulb/bifurcation.	Defines plaque and anatomic limitations.
Color or power Doppler	Bulb, bifurcation, internal and external carotid arteries.	Locates turbulence, near occlusion and residual flow.
Spectral Doppler	Common carotid systolic velocity; internal carotid systolic and diastolic velocities.	Allows ratio and NASCET grading.
Doppler angle	Correct and keep at or below 60 degrees.	Above this, velocity loses reliability.
Vertebral arteries	Flow direction, spectral pattern and asymmetry; no universal numeric cutoffs in the Brazilian document.	Assessment is qualitative and contextual.

Avoid abbreviations in teaching text: write internal carotid, common carotid, systolic velocity, diastolic velocity and internal/common ratio.

Source: CBR technical ultrasound guideline / ACR-AIUM-SPR-SRU extracranial cerebrovascular parameter

Musculoskeletal / soft tissue

Soft-tissue ultrasound should work as safe triage: confirm whether there is a lesion, localize the anatomic layer, measure in three planes, assess relationship with fascia, muscle, tendon, joint, vessels and nerves, and separate typical benign findings from indeterminate or suspicious masses. Do not promise benignity when there is doubt.

Measurements and reference values

Measurement	Usual value	Note
Soft-tissue mass — minimum documentation	three measurements, layer, fascia, margins, composition and Doppler	include history, growth, pain, trauma, anticoagulation, punctum/discharge, reducibility and comparison when usefulcomplete: two projections, three planes and Dopplerincomplete: no layer, no fascia or no Dopplerunsafe: calling benign without typical criteria
Mass size	<5 versus ≥5 cm	5 cm is a classic trigger for MRI/specialist assessment, but smaller masses may still be malignant if deep, growing or atypicalsmall typical: <5 cm and typical benignitynot decisive: <5 cm but solid/indeterminatealert: ≥5 cm
Relationship to fascia and depth	superficial, contacts fascia, crosses fascia or intramuscular/deep	below superficial fascia, intramuscular or not fully accessible by ultrasound favors MRItypical superficial: entirely subcutaneous and fully seenfascial contact: broad base or difficult deep margindeep: crosses fascia, intramuscular or not fully seen
Typical cyst, ganglion or bursa	anechoic, thin-walled, posterior enhancement, no solid component and no internal vascularity	if there are internal echoes, thick wall, nodularity or vascularity, it becomes indeterminatetypical: pure avascular cysticcomplex: debris, thin septa or inflammatory contextsolid/nodular: vascularized component
Typical superficial lipoma	oval/elliptic, well-defined, compressible, parallel to skin, echogenic or striated, without relevant vascularity	deep, large, heterogeneous, painful or growing lipoma should not be treated as simpletypical: superficial and stableatypical: heterogeneous or symptomaticnot simple: deep, ≥5 cm or rapid growth
Collection, hematoma or abscess	context + compressibility + internal echoes + peripheral Doppler	hematoma should decrease on follow-up; abscess often has pain, redness, fever or peripheral hyperemiaclear trauma: regressing hematomacomplex collection: follow-up or drainage by clinical contextinfection/expansion: fever, gas, severe pain or growth
Median nerve — wrist cross-sectional area	<9–10 mm²	≥10 mm² suggests carpal tunnel; interpret with symptoms and proximal/distal comparisonusual: <9–10 mm²borderline: 10–12 mm²enlarged: >12 mm²
Achilles tendon — thickness	4–6 mm	>7 mm suggests tendinopathy when associated with fibrillar-pattern loss, pain or hyperemia

Classifications and calculators

Interactive assistant — soft tissue, differential and next steps

Input	How the app interprets it	Limitation
Typical benign	Simple cyst/ganglion, typical superficial lipoma, foreign body with compatible history or clear dynamic hernia.	Use only if all typical criteria are present.
Indeterminate	Nonlipomatous solid, complex collection, small but atypical mass, vascularity or nonconclusive anatomic relationship.	Ultrasound should not close the diagnosis when there is overlap.
Suspicious or urgent	Deep, larger than 5 cm, growing, fixed, invasive margins, disorganized vascularity, recurrence after excision or severe infectious signs.	MRI/specialist referral according to local pathway.

Use as educational triage. The result lists possibilities, not a definitive diagnosis.

Source: SRU Radiology 2022 / BMUS 2024 / ESSR 2015 / ACR 2022

Differential by ultrasound pattern

Pattern	Common possibilities	Sign that changes management
Pure avascular cystic	Simple cyst, ganglion, distended bursa, synovial cyst.	Solid component, mural nodule or internal vascularity.
Typical superficial fatty	Superficial lipoma.	Deep, ≥5 cm, heterogeneous, painful or growing.
Nonlipomatous solid	Fibroma, nerve sheath tumor, giant cell tumor of tendon sheath, lymph node, scar endometriosis, fibromatosis.	Infiltrative margins, growth or disorganized vascularity.
Complex collection	Hematoma, seroma, abscess, Morel-Lavallée, complicated bursitis.	Fever, redness, gas, severe pain, expansion or no regression.
Vascular or compressible	Venous/lymphatic malformation, varix, pseudoaneurysm, hemangioma.	Pulsatile arterial flow, fistula, thrombus or high flow.
Dynamic with Valsalva	Hernia, muscle herniation, expansile varix.	Entrapment, marked pain, nonreducible or compromised bowel loop.
Echogenic with shadow or foreign body	Foreign body, granuloma, calcification, myositis ossificans, tophus.	Intramuscular calcification or associated mass: radiography/MRI depending on context.
Deep or invasive mass	Sarcoma and other aggressive tumors enter the differential until proven otherwise.	MRI and oncology/sarcoma referral pathway.

Source: SRU 2022 / BMUS 2024 / ESSR 2015

Warning signs — when not to close as benign

Sign	Why it matters	Color
Larger than 5 cm	Classic trigger for additional workup, especially if solid.	Red
Deep, intramuscular or crosses fascia	Ultrasound may not see full extent; MRI is preferred.	Red
Rapid growth or post-excision recurrence	Increases suspicion and changes biopsy/referral pathway.	Red
Invasive margins or disorganized vascularity	Morphologic sign of aggressiveness, although not specific alone.	Red
Isolated pain	May be inflammatory/traumatic, but is also a clinical warning sign if associated with a solid mass.	Yellow
Calcification	Occurs in benign and malignant lesions; if in an extremity or within muscle, radiography helps.	Yellow

Source: ESSR 2015 / BMUS 2024 / ACR 2022

Technical checklist — soft-tissue ultrasound

Step	Report	Reason
Targeted history	Duration, growth, pain, trauma, anticoagulation, fever/redness, punctum/discharge, reducibility and prior surgery/cancer.	Changes the differential.
Anatomic location	Side, exact point, layer: skin, subcutaneous, fascia, muscle, tendon, joint, vessel or nerve.	Avoids a generic report.
Images and measurements	Two orthogonal projections, three measurements, depth, image of deep margin and contralateral comparison if useful.	Enables follow-up.
B-mode and Doppler	Composition, echogenicity, margins, enhancement/shadowing, calcification, compressibility, peripheral/internal flow.	Separates cystic, solid, inflammatory and vascular.
Dynamic maneuvers	Compression, tendon/muscle motion, Valsalva, standing position when hernia/varix is a hypothesis.	Shows functional relationship.
Safe conclusion	Typical benign, indeterminate or suspicious; if indeterminate, clearly state that correlation/additional imaging is needed.	Protects patient and physician.

Source: BMUS 2024 / ESSR 2015 / SRU 2022

Wrist / hand (with and without Doppler)

Wrist ultrasound should separate anatomic technique, tendon assessment, peripheral nerves and joint inflammation. Doppler is not an “extra”: when synovitis, tenosynovitis, rheumatoid arthritis, infection or vascular mass is suspected, it changes interpretation.

Measurements and reference values

Measurement	Usual value	Note
Minimum protocol without Doppler	dorsal + volar + dynamic	Assess tendons in short and long axis, retinacula, radiocarpal/intercarpal joints, carpal tunnel, Guyon canal and painful point.
Protocol with Doppler	low scale and high gain without artifact	Use for synovitis, tenosynovitis, inflammatory arthritis, peritendinous hyperemia, vascular mass and infection; avoid excessive compression.
Median nerve — cross-sectional area at the carpal tunnel	<10 mm²	Fixed cutoffs vary; 10–12 mm² is a gray zone and >12 mm² is more consistent with compressive neuropathy when symptoms match.usual: <10 mm²borderline: 10–12 mm²enlarged: >12 mm²
Median nerve — wrist/forearm ratio	<1,4	Ratio ≥1.4 increases suspicion and reduces body-habitus variation; use wrist area divided by proximal forearm area.usual: <1,4suspicious: ≥1,4
Median nerve — wrist-circumference adjusted limit	0.88 × circumference − 4 mm²	Alternative described to adjust the upper normal limit by wrist circumference in centimeters.
Ulnar nerve in Guyon canal	no universal cutoff	Compare caliber, fascicles, compression, mass/cyst, ulnar artery, bifurcation into superficial sensory branch and deep motor branch.
Synovitis — OMERACT/EULAR scale	0–3 B-mode and Doppler	B-mode measures synovial hypertrophy; Doppler measures active vascularity. Interpret separately and with clinical context.

Classifications and calculators

Interactive assistant — wrist, nerves and synovitis

Input	How to interpret	Limitation
No synovitis and usual median nerve	Nerve area <10 mm², no synovial Doppler, no tenosynovitis and no erosion.	Correlate with symptoms; ultrasound does not exclude every neuropathy.
Gray zone	Nerve 10–12 mm², isolated ratio ≥1.4, grade 1 synovitis, mild Doppler or tenosynovitis without aggressive signs.	Needs clinical correlation, contralateral comparison and sometimes nerve conduction or rheumatology.
Relevant abnormal	Nerve >12 mm² with high ratio/symptoms, Doppler grade 2–3, B-mode synovitis grade 2–3, erosion, tendon rupture or motor deficit.	Do not close as incidental.

Use as educational triage. The final impression must integrate symptoms, physical exam, symptom distribution and clinical hypothesis.

Source: ESSR / AIUM / EULAR-OMERACT / Frontiers Neurology

Wrist extensor compartments — anatomic map

Compartment	Tendons	Tips and common pathology
1	Abductor pollicis longus + extensor pollicis brevis.	De Quervain tenosynovitis; look for vertical septum and accessory tendons.
2	Extensor carpi radialis longus + extensor carpi radialis brevis.	Crossing point with the first compartment in the distal forearm: intersection syndrome.
3	Extensor pollicis longus.	Use Lister tubercle as landmark; rupture risk in rheumatoid arthritis or attrition.
4	Extensor digitorum + extensor indicis proprius.	Inflammatory tenosynovitis is common; dynamic maneuver separates tendons.
5	Extensor digiti minimi.	Small and ulnar; assess tenosynovitis and rupture in inflammatory arthritis.
6	Extensor carpi ulnaris.	Assess dynamic subluxation, tendinopathy, tenosynovitis and gout/crystal deposition.

Source: ESSR wrist technical guideline / Radiopaedia anatomy

Volar side — carpal tunnel and Guyon canal

Structure	Content / landmark	What to look for
Proximal carpal tunnel	Radial scaphoid and ulnar pisiform; median nerve superficial to flexor tendons.	Median nerve area, fascicular edema, retinaculum, persistent median artery and bifid nerve.
Distal carpal tunnel	Radial trapezium and ulnar hook of hamate.	Flattening, retinacular bowing, cysts, flexor tenosynovitis and masses.
Flexor tendons inside the tunnel	Four flexor digitorum superficialis, four flexor digitorum profundus and flexor pollicis longus.	Flexor tenosynovitis, adhesion, partial tear and inflammatory trigger.
Guyon canal	Ulnar artery radial to ulnar nerve; divide into superficial sensory and deep motor branches.	Cyst/ganglion, ulnar artery thrombosis/aneurysm, compression at hamate hook and deep motor branch lesion.
Flexor carpi radialis tendon	Radial, over scaphoid/trapezium, outside the main carpal tunnel.	Tenosynovitis, tendinopathy and volar radial pain.
Flexor carpi ulnaris tendon	Inserts on pisiform; reference for Guyon canal.	Enthesopathy, calcification, crystal deposition and ulnar pain.

Source: ESSR wrist technical guideline / AIUM MSK parameter

Synovitis and rheumatoid arthritis — OMERACT/EULAR teaching scale

Grade	B-mode: synovial hypertrophy	Doppler: vascularity
0	Absent: no synovial hypertrophy.	Absent: no Doppler signal.
1	Minimal: mild thickening without major bulging.	Minimal: up to a few isolated spots/signals.
2	Moderate: hypertrophy bulges beyond the bone line with flat or concave surface.	Moderate: vascular signals in less than half of the synovial area.
3	Severe: marked hypertrophy with convex surface.	Severe: vascular signals in half or more of the synovial area.

In rheumatoid arthritis, report scanned joints, B-mode grade, Doppler grade, erosions, tenosynovitis and tendon rupture. Persistent Doppler may indicate activity even when clinical disease seems controlled.

Source: EULAR-OMERACT / SONAR recommendations / AIUM

Main wrist differentials

Condition	Useful ultrasound findings	Comment
Carpal tunnel syndrome	Enlarged median nerve, high wrist/forearm ratio, fascicular edema, distal flattening, retinacular bowing, intraneural hypervascularity.	Correlate with sensory territory and nerve conduction when needed.
De Quervain tenosynovitis	First-compartment sheath thickening, fluid, hyperemia and pain on dynamic compression.	Look for septum between abductor pollicis longus and extensor pollicis brevis.
Intersection syndrome	Friction/tenosynovitis where first-compartment tendons cross radial extensors in distal forearm.	Pain is usually more proximal than De Quervain.
Ganglion/synovial cyst	Cystic lesion with posterior enhancement, sometimes visible articular stalk, no internal flow.	If complex, vascularized or solid, reclassify as indeterminate.
Inflammatory arthritis / rheumatoid arthritis	B-mode synovitis, synovial Doppler, marginal erosions, flexor/extensor tenosynovitis and possible ruptures.	Doppler and erosion make suspicion more relevant; integrate with serology and rheumatology.
Gout or crystal disease	Heterogeneous tophi, shadowing, erosions, double contour on cartilage when visible, crystal tenosynovitis.	May mimic infection or inflammatory arthritis.
Infection	Collection, intense hyperemia, suspected purulent tenosynovitis, gas, cellulitis and marked pain.	Clinical urgency; ultrasound helps locate collection and guide aspiration.
Ligament injury/triangular fibrocartilage complex	Ultrasound partially assesses dorsal scapholunate ligament and ulnar triangular complex; use maneuvers and compare.	MRI/MR arthrography may be needed.

Source: ESSR / AIUM / EULAR-OMERACT / MSK reviews

Ankle and foot

Targeted category for pain, trauma, tendons, ligaments, plantar fascia, forefoot and inflammatory Doppler. There is no single universal system for every ankle and foot finding; therefore the reading uses green for clearly usual measurements and pattern, yellow for borderline or pain/dynamic-dependent findings, and red for tear, instability, infection, neurovascular compression, complicated diabetic foot or structurally abnormal findings.

Measurements and reference values

Measurement	Usual value	Note
Regional protocol	anterior + medial + lateral + posterior + plantar + forefoot	Use a high-frequency linear transducer; assess long and short axis, painful point, dynamic maneuvers, contralateral comparison and Doppler when inflammatory pain, mass, tenosynovitis or infection is suspected.
Achilles tendon — anteroposterior thickness	up to about 6 mm	The limit varies by sex, age, sports load and measurement site. Thickness alone does not diagnose tendinopathy; values above 6 mm, hypoechogenicity, fibrillar loss, Doppler or focal pain increase suspicion.usual if echotexture is normal: ≤6 mmborderline/contextual: >6–8 mmlikely abnormal if symptomatic: >8 mm ou defeito
Plantar fascia — thickness at calcaneal origin	<4 mm	Below 4 mm favors normality. Many studies use 4 mm as a sensitive cutoff; others find higher specificity with 4.5 to 5 mm. For safety, 4 to 4.9 mm is yellow and 5 mm or more is red when typical pain is present.strong normality: <4 mmborderline: 4–4,9 mmthickened if pain matches: ≥5 mm
Morton interdigital neuroma — largest axis	size alone does not decide mm	Lesions larger than 5 mm are more likely clinically relevant, but small symptomatic neuromas and asymptomatic lesions exist. Pain, Mulder click, dynamic compression and relation to intermetatarsal bursa matter more than size alone.less specific if isolated: <4 mmcorrelate with pain: 4–5 mmprobably relevant if symptomatic: >5 mm
Synovitis and tenosynovitis — Doppler	0–3 B-mode and Doppler	Use low scale, high gain without artifact and minimal compression. Grade 1 may be contextual; Doppler or synovial hypertrophy grades 2-3 are abnormal in inflammatory context.absent: 0mild/contextual: 1active/abnormal: 2–3
When ultrasound is not enough	focal bone pain, inability to bear weight, occult fracture, osteomyelitis or surgical planning	Radiography, CT or MRI may be needed depending on trauma, diabetic foot, bone concern, surgical plantar plate concern or complex tear.

Classifications and calculators

Interactive assistant — ankle and foot

Input	How to use	Limitation
Green	Achilles up to 6 mm, plantar fascia <4 mm, no defect, no synovial Doppler and no warning sign.	Only valid if technique and clinical context agree.
Yellow	Achilles >6-8 mm, fascia 4-4.9 mm, neuroma 4-5 mm, partial sprain, tenosynovitis or grade 1 synovitis.	Compare, test dynamically and correlate with the painful point.
Red	Tendon tear, dynamic instability, fascia ≥5 mm with typical pain, symptomatic neuroma >5 mm, synovitis/Doppler grade 2-3, infection, complicated diabetic foot or neurovascular compression.	Do not close as a variant; describe extent and guide correlation/referral.

The calculator is educational. It helps organize findings, but the final impression depends on the clinical question, physical examination, technique and contralateral comparison.

Source: AIUM / ESSR / ACR Appropriateness Criteria / EULAR-OMERACT

Anatomic map by compartments

Region	Main structures	Do not forget
Anterior	Tibialis anterior, extensor hallucis longus, extensor digitorum longus, deep peroneal nerve and dorsalis pedis artery.	Retinacula, tenosynovitis, dorsal ganglion and anterior impingement.
Medial	Posterior tibial tendon, flexor digitorum longus, posterior tibial vessels, tibial nerve and flexor hallucis longus.	Tarsal tunnel, posterior tibial tendinopathy, tenosynovitis and deltoid ligament.
Lateral	Anterior talofibular ligament, calcaneofibular ligament, peroneus brevis and longus tendons.	Sprain, tear, dynamic instability, peroneal subluxation and retinacular injury.
Posterior	Achilles tendon, paratenon, retrocalcaneal bursa, subcutaneous bursa and calcaneal insertion.	Insertional/non-insertional tendinopathy, partial/complete tear, bursitis and enthesopathy.
Plantar	Plantar fascia, fat pad, aponeurosis, plantar muscles and superficial foreign body.	Measure at the calcaneal origin; look for fibroma, tear, perifascial edema and spur without overvaluing it alone.
Forefoot and intermetatarsal spaces	Plantar plates, bursae, interdigital neuroma, flexor/extensor tendons and metatarsophalangeal joints.	Dynamic compression, Mulder sign, plantar plate and synovitis are essential.

Source: ESSR ankle and foot technical guideline / AIUM MSK parameter

Tendon and ligament injury — color reading

Finding	Interpretation	Report action
Continuous fibers, preserved echotexture and no dynamic pain	Usual pattern.	Report assessed structures and limitation if present.
Thickening or hypoechogenicity without defect	Tendinopathy/sprain; depends on pain, sport activity and comparison.	Localize, measure and mention Doppler if present.
Tenosynovitis	Fluid and/or synovial thickening of the sheath; Doppler weighs toward activity.	State which tendon and extent of involved sheath.
Partial defect	Partial tear or split; residual fibers still present.	Measure length, thickness, estimated percentage and dynamic function.
Complete discontinuity or gap	Complete tear until proven otherwise.	Measure gap/retraction and communicate if acute or functionally relevant.
Dynamic subluxation of peroneal tendons	Suggests superior retinaculum injury or lateral instability.	Report position, maneuver and involved tendons.

Source: AIUM MSK parameter / ESSR ankle-foot guideline / foot and ankle ultrasound reviews

Heel and forefoot pain — useful differentials

Condition	Ultrasound findings	Watch for
Normal plantar fascia	Thickness <4 mm, preserved fibrillar pattern, no marked perifascial edema.	Green if pain and technique agree.
Early plantar fasciopathy	4-4.9 mm, mild hypoechogenicity, focal pain or perifascial edema.	Compare with the opposite side.
Typical plantar fasciopathy or tear	≥5 mm at origin with typical pain, or focal defect/hematoma/retraction.	Measure and describe extent.
Morton interdigital neuroma	Fusiform hypoechoic nodule in the intermetatarsal space, moves with compression and may reproduce pain/click.	Size alone is not enough.
Plantar plate tear	Hypoechoic defect, dynamic instability, phalangeal subluxation or joint fluid.	MRI may help if surgical planning is considered.
Diabetic foot or infected foreign body	Collection, gas, sinus tract, foreign body, infectious tenosynovitis or bone contact.	Prioritized communication.

Source: Plantar fasciitis ultrasound reviews / AIUM / ACR foot trauma

Report checklist — ankle and foot

Item	How to report	Why it matters
Clinical question	Focal pain, trauma, instability, mass, metatarsalgia, fasciopathy, tendon or arthritis.	Defines protocol and dynamic maneuver.
Precise location	Side, region, structure, distance from landmark and relation to joint/tendon/nerve/vessel.	Avoids a generic report.
Measurements and comparison	Measure thickness, largest axis, gap, retraction, collection and compare with opposite side when useful.	Enables follow-up and treatment decision.
Dynamic assessment	Dorsiflexion, plantar flexion, eversion, inversion, interdigital compression, weight-bearing or directed maneuver according to hypothesis.	Shows instability and reproduces pain.
Doppler	Low scale, high gain without artifact, little compression and recording of hyperemia when present.	Changes synovitis, tenosynovitis and infection reading.
Limitations and referral	State when bone, occult fracture, osteomyelitis, complex injury or surgical planning requires another modality.	Protects patient and physician.

Source: AIUM / ESSR / ACR Appropriateness Criteria

Pediatric female pelvis

Normal female pelvic measurements change substantially with age, so reading is age-banded. In the neonate (<3 months), maternal estrogen makes the uterus prominent, with a cervix larger than the body (body/cervix ratio ~1:2) and a visible echogenic endometrium — this is NORMAL and involutes within weeks. In prepubertal childhood (≈4 months to 8 years) the uterus is tubular (≤4 cm, thickness <1 cm), the body/cervix ratio is ~1:1, the ovary is <1–2 cm³ and the endometrium is not visible. At puberty the fundus becomes dominant (body/cervix 2:1–3:1), the uterus reaches 5–8 cm in a pear shape, the ovary exceeds ~3.5–4 cm³ and the endometrium becomes visible/cyclic. Colors: green = within the range for age; yellow = borderline/overlap zone; red = a pubertal finding under age 8 (suspected early estrogenization) or a measurement clearly outside the band. No single measurement is diagnostic — combine uterus, ovaries, endometrium, Tanner stage and growth curve.

Measurements and reference values

Measurement	Usual value	Note
Neonate (<3 months) — estrogenized uterus	length ~2.5–3.5 cm; body/cervix ratio ~1:2; visible endometrium cm	maternal estrogen effect; involutes over the first weeks/months. A visible endometrium and small ovarian cysts are physiologic at this stage.neonatal pattern: cervix-dominant, visible endometrium, expected involutionpersistent: prominent uterus not involuting on follow-upmass/obstruction: hydrometrocolpos, complicated or large ovarian cyst
Uterus — length by age	prepubertal ≤4 cm; pubertal 5–8 cm cm	grows slowly until ~7–8 years and accelerates at puberty (Dixit: ~2.6 cm at 5y → 4.0 cm at 10y → 6.9 cm at 15–16y). Length >4–4.5 cm or a pubertal shape under age 8 favors early estrogenization.prepubertal: ≤4 cm and thickness <1 cm (tubular)borderline: 4–4.5 cm or thickness 1–1.5 cmadolescent (pubertal): 5–8 cm with fundal dominancepubertal under 8 years: >4.5 cm or thickness >1.5 cm
Body/cervix ratio (fundus/cervix)	neonate ~1:2; childhood ~1:1; pubertal 2:1–3:1	estrogenization marker: the fundus becomes dominant over the cervix with puberty. The ratio alone overlaps — combine with length, ovary and endometrium.tubular prepubertal: ≤1.2 (~1:1)transition: 1,2–1,4adolescent (pubertal): >1.4 (2:1–3:1)fundal dominance under 8 years: >1.4 (2:1–3:1)
Ovary — volume by age	prepubertal <1–2 cm³; pubertal >3.5–4 cm³ cm³	volume = 0.523 × L × W × D. Kelsey model: ~0.7 cm³ at age 2 → ~2.5 cm³ at 10 → ~7.7 cm³ at 20. There is substantial overlap between prepubertal and early pubertal.prepubertal: <1–2 cm³divergent: >2–3,5 cm³adolescent (pubertal): >3.5–4 cm³ (up to ~20 cm³)pubertal under 8 years: >3,5–4 cm³investigate mass/cyst: >20 cm³
Pediatric endometrium	prepubertal: not visible; pubertal: visible/cyclic	a visible endometrium is a specific estrogenization marker (~100% specificity, lower sensitivity). Visible in the neonate and at puberty is normal; under age 8 outside the neonatal period it is a warning sign.prepubertal: not visiblethin line: early transition — correlatepubertal/neonate: visible/cyclic expectedvisible under 8 years: cyclic/thickened outside the neonatal period
Ovarian follicles and cysts	small follicles/microcysts are physiologic at any pediatric age mm	small follicles do not indicate puberty; a dominant unilateral cyst changes interpretation and may be functional.usual childhood: <9 mmcontextual macrocystic: 9–20 mmdominant/complex: >20 mm or complex content/torsion

Classifications and calculators

Calculator — pediatric female pelvis by age

Structure	Green (normal for age)	Red (alert)
Uterine length	≤4 cm prepubertal; grows with age up to 5–8 cm in adolescence (see table)	>4.5 cm or pubertal shape under 8 years
Body/cervix ratio	~1:1 in childhood; 2:1–3:1 at puberty	>1.4 (fundal dominance) under 8 years
Ovarian volume	<1–2 cm³ prepubertal; rises with age to >3.5 cm³ in adolescence (see table)	>3.5–4 cm³ under 8 years; >20 cm³ investigate
Endometrium	not visible in childhood; visible at puberty/neonate	visible/cyclic under 8 years (outside neonate)

The calculator reads each structure by age and flags early estrogenization when a pubertal finding appears under age 8. No single criterion is diagnostic — correlate with Tanner stage, growth curve and bone age, coordinating with pediatric endocrinology.

Source: Gilligan (Pediatric Radiology 2019) / Dixit 2021 / Kelsey 2013/2016 / Herter (AJR 2002) / Radiologia Brasileira 2009

Normal by age — uterus, ovary and body/cervix ratio

Age	Uterine length (cm)	Mean ovarian volume (cm³)	Body/cervix ratio
Neonate	2,5–3,5	~1,0	~1:2
1–4 years	<3,0	~0,7–1,0	~1:1
5–6	2,6	0,5	0,9
6–7	3,1	0,6	1,0
7–8	3,3	0,8	1,1
8–9	3,5	1,3	1,3
9–10	3,8	1,8	1,3
10–11	4,0	2,0	1,3
11–12	4,6	2,1	1,3
12–13	5,5	3,0	1,5
13–14	6,1	3,5	1,5
14–15	6,5	4,4	1,7
15–16	6,9	4,6	1,8

Mean values (backbone Dixit 2021, cohort 5–16 years; neonate and 1–4 years from Radiologia Brasileira/Kelsey). These are means — use the green/yellow/red bands above and the clinical context; there is substantial overlap at early puberty.

Source: Dixit (Pediatr Endocrinol Diabetes Metab 2021) / Kelsey (PLoS ONE 2013) / Radiologia Brasileira 2009

Pediatric

Measurements and reference values

Measurement	Usual value	Note
Pylorus — muscle thickness (HPS)	> 3 mm	small infants may have HPS with lower values
Pylorus — canal length (HPS)	≥ 14–16 mm
Pylorus — diameter (HPS)	> 12 mm
Appendix — outer diameter	≤ 6 mm	≥ 6 mm and non-compressible = appendicitis (peds ~≥ 6.5 mm)

Classifications and calculators

Calculator — hypertrophic pyloric stenosis

Measure	Cutoff	Reading
Muscle thickness	≥ 3 mm	Main criterion (≥2.5 mm in preterm/<3 weeks).
Channel length	≥ 15–17 mm	Supports the diagnosis.
Pyloric diameter	≥ 13 mm	Supportive finding.
Functional	No relaxation	Observe 10–20 min in real time.

Correlate with non-bilious projectile vomiting and hypochloremic alkalosis. Borderline measurements → reassess in real time and repeat.

Source: Hernanz-Schulman (Radiology) / ACR-SPR practice parameter

Calculator — intussusception

Finding	Reading
Target <20 mm	Probably transient ileo-ileal; observe.
Target 20–25 mm	Indeterminate — reassess.
Target ≥25 mm (ileocolic)	Usually requires enema reduction.
No flow / trapped fluid / lead point	Ischemia or lower reduction success; caution.

Reduction (hydrostatic/pneumatic enema) if the child is stable and without perforation/peritonitis; otherwise surgery. A pathologic lead point warrants workup.

Source: ACR-SPR / Applegate (RadioGraphics)

Graf — hip dysplasia (infant)

Type	Alpha angle	Interpretation
I	≥ 60°	Normal/mature
IIa	50–59°	Physiologically immature (< 3 months)
IIb	50–59°	Delayed ossification (> 3 months)
IIc	43–49°	Dysplastic
III–IV	< 43°	Eccentric / dislocated

Also assess the beta angle and femoral head coverage.

Source: Graf method / Radiology Assistant

Infant hip

Infant hip ultrasound depends strongly on age, technique, and local screening policy. In the United States, selective screening for risk factors or abnormal physical examination predominates; in some European countries universal screening is used. For international safety, this reference uses colors: green for mature stable hips, yellow for physiologic immaturity or divergent thresholds, and red for dysplasia, decentering, dislocation, persistent instability, or a technically inadequate examination.

Measurements and reference values

Measurement	Usual value	Note
Ideal age and modality choice	6 weeks to 4 months is usually the most useful window	Before 6 weeks physiologic laxity increases false positives unless the physical examination is abnormal. When femoral head ossification limits visualization of the relationship with the triradiate cartilage, pelvic radiography becomes preferred.
Main indications	Abnormal or equivocal physical examination, breech presentation, family history, neuromuscular condition, or treatment follow-up	Oligohydramnios, intrauterine postural molding, asymmetric thigh creases, and leg-length discrepancy are relative indications.
Standard coronal plane	Straight iliac line + labrum + ilium/triradiate cartilage transition	The plane is reliable only when it shows a straight ilium, the labral tip, and the transition from ilium to triradiate cartilage; the acetabulum should be shown at its deepest point.
Alpha angle — bony roof	Normal: >= 60°	It is the angle between the iliac baseline and the acetabular bony roof line. It measures bony roof depth/ossification and is the main angle for Graf classification.mature: ≥60°immature/age-dependent: 50–59° antes de 13 semanasdysplastic: <50° ou 50–59° após 13 semanas
Beta angle — cartilaginous roof/labrum	Helps separate Ia/Ib and IIc/D	It is the angle between the iliac baseline and the cartilaginous roof line, drawn from the acetabular bony rim to the labrum. Beta greater than 77° with alpha from 43° to 49° suggests decentering type D.Ia when alpha is normal: <55°Ib if alpha is normal: ≥55°type D if alpha 43–49°: >77°
Femoral head coverage	Practical consensus: >= 50% well covered	Some management criteria consider 45% or higher normal; therefore 45–49% is yellow. Less than 35% is dysplastic in appropriate-use criteria.consensus normal: ≥50%normal in some sources / borderline: 35–49%dysplastic: <35%
Dynamic stability	Femoral head centered at rest and under gentle stress	In the transverse flexion view, assess ultrasound Barlow/Ortolani. More than 50% of the head should remain covered; below 45% suggests instability.

Classifications and calculators

Teaching calculator — infant hip

Green	Alpha >=60°, centered head, coverage >=50%, stable, and adequate standard plane.
Yellow	Alpha 50–59° before 13 weeks, coverage 35–49%, borderline beta, transient neonatal instability, or incomplete technique.
Red	Alpha <50°, alpha 50–59° after 13 weeks, coverage <35%, decentering/dislocation, persistent instability, or inadequate plane for conclusion.

Source: Graf method / ACR-AIUM-SPR-SRU / AAOS AUC / IHDI

Graf classification — complete reading

Type	Criterion	Practical reading
I	Alpha >=60°. Ia if beta <55°; Ib if beta >=55°.	Mature hip; no imaging follow-up if clinical examination and context agree.
IIa	Alpha 50–59° before 13 weeks.	Physiologic immaturity. Follow local protocol; IIa− or worsening requires attention.
IIb	Alpha 50–59° at 13 weeks or older.	Dysplasia due to delayed maturation; coordinate with pediatric orthopedics according to protocol.
IIc	Alpha 43–49° and beta <=77°, head still centered.	Critical dysplasia even if centered; do not treat as simple immaturity.
D	Alpha 43–49° and beta >77° or signs of decentering.	Decentering hip; alert for treatment/referral.
III–IV	Alpha <43° with eccentric or dislocated head; labrum displaced or interposed.	Severe dislocation/subluxation. Priority communication.

Source: Graf / Radiology Assistant / ACR Appropriateness Criteria

How to draw the angles

Element	How to draw it	Common error
Iliac baseline	Straight line tangential to the lateral iliac cortex in the standard coronal plane.	Using an oblique image or curved ilium; this distorts alpha and beta.
Bony roof line	Line from the acetabular bony rim to the inferior bony roof point, forming the alpha angle with the iliac line.	Choosing the wrong rounded rim or measuring away from the deepest acetabulum.
Cartilaginous roof line	Line from the acetabular bony rim to the functional center/tip of the labrum, forming the beta angle.	Drawing from the bony roof instead of the bony rim; beta becomes artificial.
Inadequate plane	If the labrum, straight ilium, or triradiate cartilage is not shown, classification should be withheld.	Classifying despite no standard plane; this creates false normal or false dysplastic results.

Source: ACR-AIUM-SPR-SRU Practice Parameter / Graf method

Coverage and dynamic stability

Finding	Color	Interpretation
Coverage >=50%	Green	Well covered by the international practical rule.
Coverage 45–49%	Yellow	Normal in some management criteria, but below the classic 50% cutoff.
Coverage 35–44%	Yellow	Borderline range in appropriate-use criteria; integrate with alpha and stability.
Coverage <35%	Red	Dysplastic in AAOS appropriate-use criteria.
Subluxable, dislocatable, or dislocated	Red	Stability weighs as much as morphology; communicate and correlate with physical examination.

Source: IHDI / AAOS AUC / ACR-AIUM-SPR-SRU

Minimum technical protocol

Step	What to record	Color if absent
Both hips	Right and left, even when the concern is unilateral.	Red if only one side was assessed without justification.
Standard coronal neutral	Morphology, femoral head position, and alpha angle.	Red: do not assign Graf classification.
Transverse flexion view	Femoral head on the ischium, position at rest and with gentle stress.	Yellow/red according to clinical concern.
Dynamic maneuver	Ultrasound Barlow; Ortolani if the head is subluxated/dislocated to assess reducibility.	Yellow if omitted; acceptable to omit in Pavlik/splint.
Documentation	Side, orientation, age, whether stress was applied, alpha, beta/coverage when used, stability, and limitations.	Yellow if incomplete.

Source: ACR-AIUM-SPR-SRU Practice Parameter 2023

Teaching pitfalls

Situation	Risk	Practical action
Younger than 6 weeks	Physiologic laxity can mimic instability.	If physical examination is normal, follow local screening policy; if abnormal, scan and describe context.
Stable Graf IIa	Many mature spontaneously, but some are IIa− or have low coverage.	Do not call fully normal; recommend follow-up according to age/protocol.
Normal alpha with instability	Mature morphology does not exclude dynamic subluxability.	Report instability and correlate with orthopedics/physical examination.
Nonstandard plane	Can change alpha and beta by several degrees.	Repeat acquisition; if still limited, report as limited.
Using Pavlik harness or splint	Stress should not be routinely applied.	Document femoral head position in the device and omit stress.

Source: ACR-AIUM-SPR-SRU / Radiology Assistant / Children’s Colorado

Adult hip

Adult hip ultrasound is a region-based targeted examination. It is very useful for anterior effusion, synovium, iliopsoas bursa, gluteal tendons, peritrochanteric bursae, dynamic snapping, collections, superficial masses and guided procedures. It does not reliably exclude labrum, deep cartilage, femoroacetabular impingement and deep bone; radiographs and MRI remain important in those scenarios. Colors separate consensus normality, gray-zone/divergent findings and abnormal or high-risk findings.

Measurements and reference values

Measurement	Usual value	Note
Minimum adult hip protocol	anterior, lateral, medial, posterior and dynamic when indicated	Anteriorly, align the transducer with the femoral neck for the anterior recess and iliopsoas. Laterally, assess the greater trochanter, gluteus medius, gluteus minimus, fascia lata and bursae. Medially, assess adductors/distal iliopsoas. Posteriorly, assess proximal hamstrings and sciatic nerve.
Transducer and depth	highest frequency that penetrates adequately	Deep hip, obesity and arthroplasty may require a curvilinear or lower-frequency transducer. Use low-scale Doppler and light compression when the question is synovitis, infection or collection.
Hip effusion — anterior capsule/femoral neck distance	5–7 mm	There is divergence: practical protocols use >5 mm or a 2 mm side difference; classic musculoskeletal literature uses 7 mm or more, and some osteoarthritis studies use 8 mm. Measure along the femoral neck axis and compare with the opposite side when possible.Green: <5 mm and no relevant asymmetryYellow: 5-6.9 mm or 1-1.9 mm side differenceRed: >=7 mm or >=2 mm side difference; urgency depends on fever, trauma, prosthesis or complex fluid
Iliopsoas bursa	normally collapsed/not visible	When visible, look for communication with the joint, pelvic extension, relation to femoral vessels and femoral nerve compression.Green: not visibleYellow: simple distention or associated tendinopathyRed: complex, bulky, infected, hemorrhagic or with neural/vascular compression
Peritrochanteric bursae	normally not visible	Lateral hip pain is rarely just bursitis; greater trochanteric pain syndrome often involves gluteus medius or minimus tendinopathy, with or without bursa.Green: bursa not visible and tendons preservedYellow: simple bursa, tendinopathy or calcificationsRed: complete tear, retraction, complex collection or possible infection
Gluteus medius and minimus tendons	fibrillar and continuous	Assess at the greater trochanter in long- and short-axis. Describe which tendon/facet is involved, thickening, hypoechogenicity, calcification, cleft, gap, retraction and Doppler.
Snapping hip — dynamic maneuver	reproduce the movement causing the snap	Internal snapping usually involves iliopsoas over the iliopectineal/femoral prominence; external snapping involves fascia lata or gluteus maximus over the trochanter. If labral/intra-articular snapping is suspected, ultrasound is limited.
Osteoarthritis — ultrasound-accessible signs	osteophytes, superficial deformity and effusion/synovitis	Ultrasound can show anterior osteophytes and deformity, but it does not replace radiography for osteoarthritis grading or MRI when cartilage/labrum are the question.
Painful hip arthroplasty	effusion, collection, mass, pseudotumor and tendons	Ultrasound helps detect collections and guide aspiration when periprosthetic infection is suspected, but an isolated finding does not replace laboratory, radiographic and orthopedic correlation.

Classifications and calculators

Interactive assistant — adult hip ultrasound

Input	Output	How to use
Normal measurements, nonvisible bursae, continuous tendons and no alert	Green	Use when the question is soft tissue/effusion and the regional protocol was documented.
5-6.9 mm recess, mild asymmetry, tendinopathy, simple bursitis or reproduced snapping	Yellow	Describe as contextual, compare with the opposite side and suggest complementary imaging if the question is deep.
>=7 mm, >=2 mm difference, complex fluid, arthroplasty collection, complete tear, fracture, deep mass or possible infection	Red	Communicate the relevant finding and route to guided aspiration, radiograph, CT, MRI or specialist assessment according to context.

Fill measurements, fluid quality, Doppler, iliopsoas, lateral tendons, bursa, visible bone, posterior region, arthroplasty and alerts to generate a color reading.

Source: AIUM-ACR-SPR-SRU / ESSR / Ann Rheum Dis / AJR / GTPS review

Anatomic roadmap by region

Region	What to assess	Pitfalls
Anterior	Hip recess, capsule, visible anterior labrum, iliopsoas, iliopsoas bursa, femoral vessels and femoral nerve when indicated.	Do not call capsular thickness synovitis without seeing fluid/synovium; compare sides.
Lateral	Greater trochanter, gluteus medius, gluteus minimus, fascia lata, gluteus maximus and bursae.	Lateral pain is often gluteal tendinopathy with or without bursa, not just “bursitis”.
Medial	Adductors, pubis, distal iliopsoas, pectineus and groin structures when the complaint allows.	Hernia and athletic pubalgia may mimic hip-joint pain.
Posterior	Proximal hamstrings, ischial tuberosity, gluteus maximus, sciatic nerve and deep masses.	Deep window may be limited; do not exclude neural compression from an incomplete exam.
Dynamic	Reproduce the movement causing snapping/pain: flexion, extension, rotation, abduction or adduction according to complaint.	If the snap is intra-articular, labrum and loose bodies are better assessed by MRI.

Source: AIUM-ACR-SPR-SRU / ESSR hip technical guideline

Hip effusion and synovitis — color reading

Finding	Green	Yellow	Red
Capsule/femoral neck distance	<5 mm	5-6.9 mm	>=7 mm; some studies use 8 mm
Contralateral comparison	<1 mm difference	1-1.9 mm	>=2 mm in practical protocols; >=1 mm in some studies
Fluid quality	no fluid or simple trace	simple effusion	debris, septa, gas, pus, blood or suspicious postoperative setting
Synovial Doppler	no flow	mild/moderate	intense with fever, prosthesis, wound or disabling pain

In adults, ultrasound detects distention and guides aspiration, but small effusion may be difficult and etiology is not defined by ultrasound alone.

Source: Ann Rheum Dis 2000 / AJR 2003 / Emory Emergency Ultrasound

Lateral hip pain — greater trochanteric pain syndrome

Structure	Normal/low risk	Caution	High risk
Gluteus medius/minimus	fibrillar and continuous	thickening, hypoechogenicity, calcification or partial cleft	complete tear, retraction or important atrophy
Trochanteric bursa	not visible	small simple distention	complex, hyperemic or possible infection
Fascia lata/gluteus maximus	smooth gliding	reproduced external snapping	disabling pain, associated tear or mass

Clinical review emphasizes that lateral trochanteric pain should not be reduced to “bursitis”; gluteal tendinopathy is common.

Source: Br J Gen Pract 2017 / ESSR / AIUM

Anterior pain, iliopsoas and snapping

Pattern	Ultrasound clue	Practical reading
Normal iliopsoas	striated muscle, echogenic tendon and nonvisible bursa	Green if pain is not reproduced and no collection is present.
Iliopsoas tendinopathy	thickening, hypoechogenicity, focal pain or Doppler	Describe along the course and relation with bursa.
Internal snapping	iliopsoas tendon snaps dynamically during the maneuver	Record movement used and whether it reproduced pain.
Complex/bulky bursa	deep collection between iliopsoas and capsule, possibly extending to pelvis	Assess infection, bleeding, joint communication and femoral compression.

Source: ESSR / IJSPT iliopsoas review / AJR dynamic snapping hip

Painful arthroplasty and priority-changing findings

Scenario	Ultrasound finding	Teaching action
Possible infection	effusion/collection, complex fluid, hyperemia, wound or fever	Communicate and consider guided aspiration according to local protocol.
Mass or pseudotumor	periprosthetic mass, deep extension or neurovascular relation	Measure, map extent and suggest complementary imaging.
Trauma or fracture	cortical step, avulsion, deep hematoma or inability to bear weight	Radiograph/CT or orthopedic assessment according to scenario.
Arthroplasty limitation	artifact, shadowing, depth or pain prevents complete assessment	Do not exclude deep complication; record limitation.

Source: AIUM-ACR-SPR-SRU / AJR prosthetic hip infection sonography

Useful adult hip differential diagnoses

Complaint	Ultrasound possibilities	When to remember another modality
Anterior/groin pain	effusion, synovitis, iliopsoas, bursa, adductors, hernia or lymph node	Labrum, cartilage, impingement and avascular necrosis require MRI/radiograph.
Lateral pain	gluteal tendinopathy, bursa, external snapping, calcification or mass	Lumbar/radicular pain may mimic trochanteric pain.
Posterior pain	proximal hamstrings, sciatic nerve, hematoma or deep mass	Neurologic deficit, deep mass or avulsion requires complementary imaging.
Fever or inability to bear weight	effusion, synovitis, collection, abscess or complicated prosthesis	Do not delay aspiration/urgent assessment when clinical concern is strong.

Source: AIUM / ESSR / Ann Rheum Dis / GTPS review

Adult hip report checklist

Item	Question the report should answer
Technique	Were side, transducer, assessed region, position, contralateral comparison and dynamic maneuver when indicated described?
Measurements	Were anterior recess, asymmetry, bursa, collection, mass or tendon gap measured when present?
Limitations	Does the report state that labrum, deep cartilage, impingement and deep bone are not well excluded by ultrasound?
Alert	Is there communication for possible infection, arthroplasty collection, complete tear, fracture, deep mass or neural compression?

Source: Best-practice synthesis from AIUM / ESSR / AJR / clinical reviews

Arterial Doppler — limbs and arteriovenous fistula

Integrated category for lower-limb arterial Doppler, upper-limb arterial Doppler, pre-creation mapping for arteriovenous fistula and evaluation of a working arteriovenous fistula. Stenosis cutoffs by velocity ratio are practical and widely used, but may vary by laboratory, segment, graft, stent, Doppler angle and collateral circulation.

Measurements and reference values

Measurement	Usual value	Note
Abdominal aorta — diameter	< 3 cm	≥ 3 cm = aneurysm
Common iliac artery — diameter	≈ 8–10 mm
Common femoral artery — diameter	≈ 5–9 mm
Lower-limb arterial protocol	aorta, iliac, femoral, popliteal, tibial and dorsalis pedis arteries	Document peak systolic velocity, spectral waveform, color/aliasing and comparison with a normal proximal segment. When there is a focal jet, calculate the velocity ratio.
Upper-limb arterial protocol	subclavian, axillary, brachial, radial, ulnar and palmar arch when indicated	For arteriovenous fistula planning, assess dominance, patency, calcification, diameter, reactive hyperemia and radial-ulnar/palmar communication according to local protocol.
Pre-fistula mapping — donor artery	> 2,0 mm	Arterial diameter above 2.0 mm is a common target for native arteriovenous fistula; below that, decisions depend on pulse, calcification, reactive hyperemia and surgical strategy.good candidate: >2.0 mm and no limiting calcificationgray zone: 1,5–2,0 mmhigh technical risk: <1.5 mm, occlusion or marked calcification
Pre-fistula mapping — superficial vein	> 2,5 mm	Vein above 2.5 mm is a common target for arteriovenous fistula; for grafts, many protocols use vein above 4.0 mm. Compressibility, continuity and depth are as important as diameter.favorable for fistula: >2.5 mm, compressible and continuousborderline: 2,0–2,5 mm ou profundidade > 6 mmunfavorable: <2.0 mm, thrombosis or noncompressible
Working arteriovenous fistula — access flow	interpret with trend and clinical context mL/min	Older practical rules use 600 mL/min as a maturation target, but modern guidance emphasizes physical examination, dialysis performance, flow trend and focal stenosis findings.

Classifications and calculators

Interactive assistant — stenosis, waveform and arteriovenous fistula

Input	Output	How to use
Velocity ratio <1.5 and multiphasic waveform	Green	Favors no hemodynamically relevant stenosis in the analyzed segment.
Ratio 1.5-1.99 or isolated biphasic/monophasic waveform	Yellow	Borderline zone: confirm angle, sampling at the jet, proximal reference segment and contralateral comparison.
Ratio >=2, distal tardus-parvus waveform, absent flow or thrombosis	Red	Treat as abnormal until proven otherwise; document location, highest velocity, ratio and distal waveform.

Fill the cells below to obtain velocity ratio, likely stenosis grade, waveform reading, tardus-parvus suspicion and arteriovenous fistula triage.

Source: StatPearls/NCBI / Society for Vascular Medicine / SVU-SVM / KDOQI

Peripheral arterial stenosis by velocity ratio

Interpretation	Velocity ratio	Note
No relevant stenosis	< 1,5	Multiphasic waveform and no focal aliasing favor normality in the segment.
Likely mild stenosis	1,5–1,99	Often estimated as 30-49%; confirm technique and avoid overcalling in isolation.
Hemodynamically significant stenosis	2,0–4,0	Compatible with at least 50% stenosis in many protocols; look for focal jet, turbulence and distal change.
Severe stenosis	> 4,0	Suggests greater than 75-80% stenosis when sampling is correct and morphology agrees.
Occlusion	no demonstrable flow	Confirm gain, scale, angle and collaterals before concluding; distal waveform may be reconstituted by collaterals.

Ratio = peak systolic velocity at the jet or suspicious point divided by peak systolic velocity in the normal proximal segment. Specific segments, stents and grafts may require their own criteria.

Source: StatPearls/NCBI Bookshelf / Society for Vascular Medicine / IAC

Peripheral arterial waveform patterns

Pattern	Color	Practical meaning
Multiphasic with rapid systolic upstroke	Green	Expected pattern in healthy peripheral arteries, especially at rest.
Biphasic with preserved amplitude	Yellow	May be acceptable in some older patients or after vasodilation, but deserves comparison and context.
Low-resistance monophasic with still rapid upstroke	Yellow	May occur distally after exercise, inflammation, hyperemia or fistula; it is not always proximal stenosis.
Damped monophasic or tardus-parvus	Red	Slow upstroke, rounded peak and low amplitude suggest inflow disease or proximal stenosis.
Absent flow where flow should be present	Red	Consider occlusion, thrombosis, severe spasm or technical error; confirm with color, power Doppler and spectral Doppler.

Source: SVU-SVM peripheral arterial waveform consensus / IAC

Arteriovenous fistula — pre-creation and follow-up

Scenario	Green	Yellow	Red
Donor artery	>2.0 mm, patent, adequate pulse and no limiting calcification	1.5-2.0 mm or weak reactive hyperemia	<1.5 mm, occlusion, severe calcification or relevant steal
Candidate superficial vein	>2.5 mm, compressible, continuous and favorable depth	2.0-2.5 mm, depth >6 mm or short segment	<2.0 mm, thrombosis, sclerosis or noncompressible
Working fistula — access flow	Functional, stable trend and usually >600 mL/min	400-600 mL/min, progressive drop or very high flow without symptoms	<400-500 mL/min with dysfunction, thrombosis, nonmaturation or very high flow with cardiac impact
Fistula stenosis	No focal jet, no critical turbulence and favorable physical examination	Focal jet with ratio 2-3 or isolated finding without flow drop	Ratio >3, marked jet, post-stenotic change, thrombus, aneurysm/pseudoaneurysm or clinical change

Intervention decisions in hemodialysis access should not depend on a single velocity: integrate physical examination, cannulation difficulty, dialysis venous pressure, flow decline, arm swelling and access history.

Source: KDOQI 2019 / AIUM postoperative hemodialysis access / ACR-AIUM-SRU

Salivary glands

Brazil and other regions: parotid, submandibular and sublingual glands should be assessed as a dedicated examination when requested. Ultrasound is strong for superficial parenchyma, stones, dilated duct, collection, lymph nodes and guided sampling; it is limited for the deep parotid lobe, perineural spread, skull base and deep staging, where computed tomography or magnetic resonance may be needed.

Measurements and reference values

Measurement	Usual value	Note
Minimum protocol	high-frequency linear transducer; transverse, longitudinal and anteroposterior planes; bilateral comparison; color/power Doppler in lesions	Assess parenchyma, echogenicity, ducts, stone, collection, mass, cervical lymph nodes and relationship with skin, masseter, mandible, oral floor and vessels. Every focal lesion should be measured in three axes.
Parotid — approximate cut-surface area	≈ 3–4 cm²	Teaching value, not universal. Comparison with the opposite side, atrophy, post-treatment change, inflammation and body habitus matter more than an isolated cutoff.teaching range: 3–4 cm²contextual: outside range or asymmetry
Submandibular — approximate cut-surface area	≈ 1–2 cm²	Teaching value. A small/atrophic gland may occur with age, chronic obstruction, Sjögren, radioiodine or radiation therapy; enlargement may be inflammatory/obstructive.teaching range: 1–2 cm²contextual: outside range or asymmetry
Main salivary duct	normally not visible	A visible, dilated duct or transition point suggests obstruction/stenosis when associated with meal-related pain, stone, gland swelling or purulent secretion.usual: duct not visible and no obstructive symptomsgray zone: isolated visible duct or suspected stenosis without stoneabnormal: dilated duct with stone, meal pain, pus or collection
Sialolithiasis	intraductal echogenic focus with shadow/twinkle + proximal dilatation	Ultrasound sensitivity varies with stone size/location and ductal dilatation; a small stone without a dilated duct can be false negative. Calcification outside the duct may be a calcified node, phlebolith or vascular calcification.suspicious: calcification without clear ductal continuityconsensus abnormal: intraductal stone with shadow/twinkle and dilated duct
Focal salivary lesion	measure three axes + Doppler + lymph nodes	Size alone does not define benignity. Irregularity, infiltration, extraglandular extension, facial palsy, suspicious nodes, rapid growth or progressive pain increase risk.indeterminate: solid/cystic mass without aggressive signshigh risk: infiltrative margins, extension, facial nerve or suspicious nodes

Classifications and calculators

Interactive assistant — salivary glands

Source: ACR-AIUM-SPR-SRU Head and Neck / Iowa / OMERACT / AJR

Sjögren — OMERACT 0-3 per gland

Grade	Finding	Teaching color
0	Normal/homogeneous parenchyma	Green
1	Mild inhomogeneity without defined hypoechoic/anechoic areas	Yellow
2	Moderate change with focal hypoechoic/anechoic areas surrounded by preserved parenchyma	Yellow/Red by context
3	Severe change: diffuse hypo/anechoic areas involving the gland, fibrosis or fatty replacement	Red when concordant with clinical/serologic context

OMERACT is a structural per-gland scale. Recent studies explore 0-12 sum and 0-6 ordinal scores; high thresholds have higher specificity, but ultrasound does not replace clinical criteria, serology, sialometry or biopsy when needed.

Source: OMERACT / RMD Open 2021 / Arthritis Res Ther 2026

Salivary obstruction — color reading

Finding	Green	Yellow	Red
Duct	not visible	isolated visibility or salivary stimulation changes caliber	dilated with transition point, stone, pus or collection
Stone	absent	calcification without clear ductal continuity	intraductal focus with shadow/twinkle and proximal dilatation
Infection	no hyperemia/collection	painful/hypervascular gland without collection	abscess, gas, cellulitis, fever or purulent secretion

Absence of a stone on ultrasound does not exclude treatable duct stenosis; duct dilatation has high predictive value for stenosis in sialendoscopy series.

Source: Iowa Head and Neck Protocols / AJR 2013

Salivary mass — differential and risk signs

Pattern	Useful differentials	What changes priority
Well-defined solid	pleomorphic adenoma, Warthin tumor, intraparotid lymph node, oncocytoma	measure 3 axes, Doppler and nodes; sampling according to local protocol
Cystic	ranula, sialocele, lymphoepithelial cyst, cystic node, abscess, cystic tumor	complex content, hyperemia, gas or fever increase urgency
Infiltrative/aggressive	primary malignancy, metastasis, lymphoma, carcinoma ex pleomorphic adenoma	irregular margins, extraglandular extension, facial palsy, rapid growth or suspicious nodes
Bilateral/multifocal	Warthin, Sjögren, HIV, IgG4-related disease, sarcoidosis, lymphoma	integrate age, smoking, sicca, serology, HIV and distribution

Source: ACR-AIUM-SPR-SRU Head and Neck / StatPearls / salivary tumor imaging reviews

Teaching report checklist

Item	Safety question
Coverage	Which gland and side were assessed? Was contralateral comparison performed?
Duct/stone	Was the duct seen? Is there dilatation, transition point, stone with shadow/twinkle or meal-related pain?
Focal lesion	Was the lesion measured in three axes, with margins, content, Doppler, deep plane and nodes?
Sjögren	Were the four major glands scored when the question is sicca/Sjögren?
Communication	Were abscess/gas, facial palsy, extraglandular extension, suspicious nodes or infiltrative mass highlighted?

Source: SonoAI synthesis from cited sources

Shoulder / rotator cuff

Shoulder ultrasound should be read by structures, not by a single measurement. The examination is strong for rotator cuff, long head of biceps, subacromial-subdeltoid bursa, superficial acromioclavicular joint, posterior recess and dynamic assessment; it is limited for deep labrum, cartilage, bone marrow and complex instability. The colors below separate consensus normality, borderline or context-dependent zones and consensus abnormal findings.

Measurements and reference values

Measurement	Usual value	Note
Minimum shoulder protocol	biceps, subscapularis, supraspinatus, infraspinatus, teres minor, bursa, acromioclavicular joint, posterior recess and dynamic maneuvers when indicated	Examine seated when possible, adapt to pain and range of motion, document in short and long axis and measure abnormalities in two orthogonal planes.
Technique and positioning	high-frequency linear transducer; forearm supinated for biceps; external rotation for subscapularis; hand in back pocket for supraspinatus; posterior sweep for infraspinatus and teres minor	Avoid anisotropy and remember that forced internal rotation may overestimate supraspinatus tear size.
Subacromial-subdeltoid bursa — thickness/fluid	<2 mm	Normal fluid is rarely thicker than 2 mm and tends to be posterior; greater than 3 mm, fluid medial to the acromioclavicular joint or anterior to the humerus is abnormal.Green: up to 2 mm, posterior, without hyperemia and without focal painYellow: >2 to 3 mm or small context-dependent fluidRed: >3 mm, anterior/medial fluid, complex content or hyperemia with inflammatory/infectious concern
Partial rotator cuff tear — Ellman depth	<3 / 3–6 / >6 mm	Also classify as articular-sided, bursal-sided or intrasubstance; measure depth and extent. Greater than 6 mm usually represents more than half tendon thickness.Green: no focal defect and continuous fibersYellow: Ellman I <3 mm or Ellman II 3-6 mmRed: Ellman III >6 mm or more than 50% thickness
Full-thickness tear — essential measurements	width in short axis + retraction in long axis	Describe involved tendons, communication with the bursa, retraction, width, muscle bulk and fatty infiltration when visible; compare with the opposite side when useful.Green: no tendon discontinuityRed: full-thickness defect, retraction or large/massive tear
Long head of biceps	centered in the groove, fibrillar, without relevant sheath distention	Assess in short and long axis. Fluid, synovitis or hyperemia suggest tenosynovitis; subluxation/dislocation should raise concern for subscapularis or rotator interval injury.Green: centered, fibrillar, without hyperemiaYellow: tenosynovitis, tendinopathy or mild fluidRed: subluxation, dislocation or tear
Shoulder Doppler	bursa, biceps sheath, joint synovium and painful tendon	Color or power Doppler helps detect hyperemia in bursitis, tenosynovitis, synovitis, calcific crisis, postoperative repair or infection.Green: no hyperemia in the right contextYellow: mild or moderate hyperemia without systemic signsRed: intense hyperemia with fever, wound, postoperative status, complex bursa or collection
Important limitations	deep labrum, cartilage, bone marrow, complex instability and occult fracture	When the clinical question is deep or osseous, ultrasound should guide but not replace radiographs, MRI or CT according to context.

Classifications and calculators

Interactive assistant — shoulder ultrasound

Color	How to interpret
Green	Thin bursa, continuous tendons, centered biceps, no effusion, no hyperemia and no critical limitation in completed fields.
Yellow	Gray zone: tendinopathy, superficial/intermediate partial tear, small bursa, hyperemia without systemic signs, dynamic impingement or deep labral question.
Red	Consensus abnormal or high-impact finding: bursa above 3 mm, full-thickness tear, Ellman III, biceps dislocation, muscle atrophy, pseudoparalysis, fever/infection, suspected fracture/dislocation.

Fill measurements and structures in the panel to generate color, critical points and next step. The assistant does not replace medical judgment or integration with radiographs/MRI.

Source: AIUM-ACR-SPR-SRU / ESSR / PubMed / Ellman

Anatomic structure-by-structure checklist

Structure	How to examine	Do not forget
Long head of biceps	Forearm supinated; short axis in the bicipital groove and long axis to the myotendinous junction.	Confirm position in the groove, sheath fluid, hyperemia, subluxation, dislocation or tear.
Subscapularis	Elbow at the side, external rotation; sweep from myotendinous junction to lesser tuberosity insertion.	Dynamic maneuver helps detect biceps instability and subcoracoid impingement.
Supraspinatus	Hand in back pocket or modified position according to pain; assess long and short axis while keeping the beam perpendicular.	Compress the tendon to reveal a nonretracted tear; measure depth, extent and retraction when a defect is present.
Infraspinatus and teres minor	Posterior sweep below the scapular spine, with internal and external rotation when useful.	Look for atrophy, fatty infiltration, posterior tear and paralabral cyst at the spinoglenoid notch.
Bursa and dynamic impingement	Assess the bursa at rest and during abduction in internal rotation if symptoms suggest impingement.	Pain with bursal/tendon bunching is contextual; bursa above 3 mm is abnormal.
Acromioclavicular joint and posterior recess	Transducer at the shoulder apex for the acromioclavicular joint; posterior transverse plane at the glenohumeral joint space.	Describe osteoarthritis, synovitis, trauma, posterior effusion, paralabral cyst and indirect labral signs.

Source: AIUM-ACR-SPR-SRU / ESSR shoulder guideline

Rotator cuff — color reading

Finding	Green	Yellow	Red
Tendon and echotexture	continuous fibers, compatible thickness/echotexture, no focal pain	tendinopathy, calcification, hypoechogenicity or compression pain	complete discontinuity, retraction or large defect
Partial tear	no focal defect	Ellman I <3 mm or Ellman II 3-6 mm; state articular, bursal or intrasubstance side	Ellman III >6 mm or more than 50% thickness
Full-thickness tear	not present	suspicion limited by pain, anisotropy or incomplete window	defect crossing full thickness, communication with bursa, retraction or massive tear
Rotator cuff muscles	preserved and symmetric bulk	mild atrophy or difficult comparison	evident atrophy/fatty infiltration, especially with tear

Source: AIUM-ACR-SPR-SRU / Ellman

Bursa, biceps and Doppler — practical interpretation

Structure	Green	Yellow	Red
Subacromial-subdeltoid bursa	up to 2 mm, posterior, without hyperemia	>2-3 mm or small context-dependent fluid	>3 mm, anterior/medial fluid, complex content or marked hyperemia
Long head of biceps	centered, fibrillar, without relevant fluid	tenosynovitis, tendinopathy or mild fluid	subluxation, dislocation or tear
Doppler	no hyperemia in the right context	mild/moderate hyperemia without systemic signs	intense hyperemia with fever, wound, postoperative status, complex bursa or collection
Acromioclavicular joint	no focal pain or distention	osteoarthritis, osteophytes or capsulitis/synovitis	suspected separation/dislocation or infection

Source: PubMed PMID 16628056 / AIUM-ACR-SPR-SRU

Useful shoulder differential diagnoses

Presentation	Consider	Role of ultrasound
Lateral pain and painful arc	supraspinatus tendinopathy, bursitis, subacromial impingement, calcific tendinopathy	assess cuff, bursa and dynamic maneuver; Doppler helps in active phase
Anterior pain	biceps, subscapularis, rotator interval, acromioclavicular joint	confirm biceps in groove, fluid, hyperemia, subluxation and subscapularis tendon
Global stiffness	adhesive capsulitis, arthropathy, pain limitation, postoperative state	ultrasound may show synovitis/bursa, but diagnosis is clinical and may require MRI
Acute trauma or sudden strength loss	complete tear, avulsion, occult fracture, dislocation, biceps injury	measure tear and retraction; radiographs/MRI according to bone or surgical concern
Neurologic weakness or atrophy	suprascapular nerve compression, paralabral cyst, neuropathy, chronic tear	look for cyst at the suprascapular/spinoglenoid notch and compare muscles
Fever, wound or painful postoperative state	infection, abscess, septic bursa, collection, retear	Doppler, complex content and guided aspiration may change management

Source: AIUM-ACR-SPR-SRU / ESSR / MSK ultrasound reviews

Teaching checklist for the shoulder report

Item	Safety question
Structure-based protocol	Were biceps, subscapularis, supraspinatus, infraspinatus/teres minor, bursa, acromioclavicular joint and posterior recess documented?
Measurements	Does a partial tear have depth and side? Does a full-thickness tear have width and retraction?
Doppler and dynamics	Was hyperemia documented when there was pain, bursa, fluid, postoperative state or inflammatory concern? Was impingement tested when indicated?
Priority-changing findings	Were full-thickness tear, Ellman III, bursa above 3 mm, biceps dislocation, fever, collection, pseudoparalysis or suspected fracture/dislocation highlighted?
Limitations	Was it stated when labrum, cartilage, deep bone, pain or mobility limited the examination?

Source: AIUM-ACR-SPR-SRU / ESSR

Knee

Knee ultrasound is a compartment-based targeted examination. It is strong for effusion, synovium, bursae, tendons, superficial collateral ligaments, Baker cyst and periarticular masses; it is limited for deep cartilage, cruciate ligaments and the central menisci. The colors below separate consensus normality, borderline/divergent zones and abnormal or high-risk findings.

Measurements and reference values

Measurement	Usual value	Note
Minimum knee protocol	anterior, medial, lateral, posterior and dynamic	Document the suprapatellar recess, patellar and quadriceps tendons, collateral ligaments, accessible menisci, bursae, Baker cyst, popliteal fossa and dynamic comparison when useful.
Effusion — suprapatellar recess	3,6–6,0 mm	There is no single cutoff: 3.6 mm increases sensitivity, 6 mm increases specificity; some services use 4 mm. Prefer longitudinal measurement with the knee around 30 degrees flexed.Green: <2 mm without inflammatory contextYellow: 2-5.9 mm or cutoff disagreementRed: ≥6 mm with fever, trauma, postoperative status or complex fluid
Patellar tendon — thickness	4–5 mm	Thickness alone does not diagnose tendinopathy; correlate with hypoechogenicity, fibrillar loss, Doppler, enthesis and focal pain.Green: 4-5 mm with preserved echotextureYellow: >5 mm or focal thickening
Quadriceps tendon — thickness	no universal cutoff	Measurements vary with technique, sex, activity and measurement point. Use the calculator as a contextual alert, not as a standalone diagnosis.Green: continuous fibers and no focal painYellow: thickening, hypoechogenicity or DopplerRed: complete discontinuity or retraction
Meniscal extrusion	3 mm	Three millimeters is a practical but not absolute cutoff; loading, age, osteoarthritis, technique and MRI change interpretation.Green: <2 mmYellow: 2-4.9 mm or degenerative contextRed: ≥5 mm, especially with root-tear concern or advanced osteoarthritis
Medial collateral ligament — thickness	3,3–5,6 mm	Range described at the femoral attachment. Thickening is more meaningful with edema, focal pain, fibrillar loss or instability.Green: up to 5.6 mm at the femoral point with preserved fibersYellow: >5.6 mm or edema without tearRed: complete discontinuity or avulsion
Iliotibial band — thickness	~1,1 mm	Values above 2-3 mm, with edema or deep fluid near the lateral femoral condyle, favor iliotibial band syndrome.Green: ≤2 mm without edemaYellow: >2-3 mm or dynamic lateral painRed: >3 mm with typical deep edema/fluid
Baker's cyst	neck between semimembranosus and medial gastrocnemius	A posterior cyst may drain knee fluid; absence of suprapatellar fluid does not exclude effusion when a Baker cyst is present.Yellow: simple or septated, without rupture signsRed: ruptured, dissecting into calf or mimicking thrombosis
Prepatellar and pes anserine bursae	normally not visible	Simple distension is usually contextual; complex content, gas, intense hyperemia or wound raises priority.

Classifications and calculators

Interactive assistant — knee ultrasound

Input	Output	How to use
Measurements in range and no clinical alert	Green	Use when the minimum protocol was documented and a deep structure is not the main question.
Small effusion, mild synovitis, tendinopathy, simple bursitis or borderline meniscal extrusion	Yellow	Describe as contextual, compare with the opposite side when useful and suggest clinical correlation or MRI if the question is internal.
Possible infection, complete tear, fracture/avulsion, thrombosis/aneurysm, ruptured cyst or significant effusion in a risk context	Red	Communicate priority and route to orthopedics, rheumatology, vascular care or emergency according to the dominant pattern.

Fill measurements, synovium, tendons, menisci, ligaments, Baker cyst, posterior region and warning signs to generate a color reading.

Source: ESSR / EULAR-OMERACT / J Diagn Med Sonogr / RadioGraphics

Anatomic roadmap by compartment

Compartment	What to assess	Pitfalls
Anterior	Suprapatellar recess, quadriceps tendon, patellar tendon, Hoffa fat pad and prepatellar bursa.	Fluid redistributes with flexion; also scan medial and lateral to the quadriceps tendon.
Medial	Medial collateral ligament, peripheral medial meniscus, pes anserine region and osteophytes.	Meniscal extrusion depends on loading, osteoarthritis and technique; do not diagnose root tear by ultrasound alone.
Lateral	Iliotibial band, lateral complex, peripheral lateral meniscus, fibular head and common peroneal nerve.	Anisotropy may mimic ligament injury; use long- and short-axis views.
Posterior	Baker cyst, popliteal fossa, artery, vein, tibial nerve and common peroneal nerve.	Ruptured cyst may mimic thrombosis; with calf swelling, perform compression venous assessment.

Source: ESSR knee technical guidelines / RadioGraphics

Effusion and synovitis — color reading

Finding	Green	Yellow	Red
Suprapatellar recess	<2 mm and no synovitis	2-5.9 mm or divergent cutoff	≥6 mm with fever, trauma, postoperative status or complex fluid
Greyscale synovium	no hypertrophy	grade 1-2	grade 3 or exuberant synovial mass
Synovial Doppler	no flow	few signals or moderate flow	intense flow or associated infection concern

Effusion and synovitis are not synonyms: fluid may be mechanical/traumatic; synovial hypertrophy with Doppler suggests inflammatory activity.

Source: J Diagn Med Sonogr 2020 / EULAR-OMERACT

Simplified EULAR-OMERACT synovitis score

Grade	Greyscale	Doppler	Practical reading
0	no synovial hypertrophy	no Doppler signal	no active synovitis by score
1	minimal hypertrophy	few punctate signals	mild or early activity
2	moderate hypertrophy	confluent flow in less than half of synovium	probable inflammatory activity
3	marked hypertrophy	flow in more than half of synovium	important activity; correlate with inflammatory arthritis or infection according to context

Source: EULAR-OMERACT / RMD Open

Extensor mechanism and tendons

Structure	Normal/low risk	Caution	High risk
Patellar tendon	4-5 mm, fibrillar and no Doppler	>5 mm, hypoechogenicity, enthesopathy or Doppler	complete tear or avulsion
Quadriceps tendon	continuous fibers	thickening or partial tear	complete discontinuity, retraction or extension inability
Hoffa fat pad and prepatellar bursa	no distension or hyperemia	edema, simple bursitis or anterior impingement	complex content, gas, wound or possible infection

Source: RadioGraphics knee US / AJR patellar tendon

Menisci, collateral ligaments and iliotibial band

Structure	Green	Yellow	Red
Meniscal extrusion	<2 mm	2-4.9 mm; 3 mm is practical, not absolute	≥5 mm or root-tear/advanced osteoarthritis concern
Medial collateral ligament	continuous fibers; up to 5.6 mm at the described femoral point	thickening, edema or partial tear	complete tear or avulsion
Lateral complex	continuous fibers and no focal pain	sprain, thickening or partial tear	complete tear, avulsion or posterolateral instability
Iliotibial band	≤2 mm without deep edema	>2-3 mm or dynamic pain	>3 mm with typical deep edema/fluid

Source: Orthopedic Reviews / Skeletal Radiology / RadioGraphics

Posterior knee and differential diagnoses

Finding	Ultrasound clue	Teaching action
Baker's cyst	typical neck between semimembranosus and medial gastrocnemius	measure, describe simple/complex and look for effusion/synovitis
Ruptured Baker's cyst	fluid dissecting into calf	differentiate from thrombosis, hematoma and cellulitis
Popliteal thrombosis	noncompressible vein or thrombus	activate venous protocol; do not treat as isolated cyst
Aneurysm or pseudoaneurysm	pulsatile mass, yin-yang flow or arterial neck	use Doppler and communicate vascular finding
Ganglion or intraneural cyst	relationship with common peroneal or tibial nerve	document neural course and relation to fibular head

Source: ESSR / RadioGraphics knee US

Knee report checklist

Item	Question the report should answer
Technique	Were transducer, compartments assessed, position/flexion and dynamic maneuvers described?
Measurements	Were effusion, tendons, meniscal extrusion, ligament thickening or cyst measured when present?
Limitation	Does the conclusion avoid excluding central meniscus, deep cartilage and cruciate ligaments when not assessable?
Alert	Is there a communication phrase for possible infection, complete tear, thrombosis/aneurysm or fracture/avulsion?

Source: Best-practice synthesis from ESSR / EULAR-OMERACT / RadioGraphics

Abdominal wall / hernias

Measurements and reference values

Measurement	Usual value	Note
Technique — dynamic maneuver	—	Valsalva / standing increase sensitivity (detect occult hernia)
Transducer	7,5–10 MHz	linear; sens. 86–96%, spec. 77–96% (inguinal)

Classifications and calculators

Hernia types — US location

Type	Finding
Indirect inguinal	Antero-lateral to the spermatic cord
Direct inguinal	Medial/posterior to the cord; conjoint tendon bulge on Valsalva
Femoral	Medial to the femoral vein
Umbilical / epigastric / incisional	Midline / scar defect, with sac and contents

Diagnosis = contents (fat/bowel) crossing the fascial defect; measure the defect.

Source: AJR 2006

Inguinal regions

Category for targeted groin ultrasound: hernia, lymph node, mass, collection, vascular complication and postoperative assessment. There is no single universal system for all these findings; therefore the reading uses green for a complete dynamic exam without abnormality, yellow for small/indeterminate findings or divergent references, and red for complicated hernia, relevant femoral hernia, morphologically suspicious node, pseudoaneurysm, thrombosis or infection.

Measurements and reference values

Measurement	Usual value	Note
Minimum groin protocol	high-frequency linear + rest + dynamic maneuver	Use a high-frequency linear transducer and scan the painful point, inguinal canal, femoral region, femoral vessels and contralateral side when the finding is equivocal. Valsalva, coughing and upright scanning increase sensitivity for occult hernia.
Mandatory anatomic landmarks	inferior epigastric vessels, inguinal ligament, femoral vein	Avoid abbreviations in teaching reports: write inferior epigastric vessels, inguinal canal, Hesselbach triangle, inguinal ligament, femoral vein and deep inguinal ring.
Indirect inguinal hernia	lateral to the inferior epigastric vessels	The neck is usually at the deep inguinal ring and the contents may course through the inguinal canal toward the scrotum or labia majora.
Direct inguinal hernia	medial to the inferior epigastric vessels	Occurs in Hesselbach triangle, above the inguinal ligament; posterior-wall bulging with Valsalva may precede an evident direct hernia.
Femoral hernia	inferior to the inguinal ligament and medial to the femoral vein	It has a higher complication risk than inguinal hernia; bowel, pain, nonreducibility, sac fluid or obstruction signs should be communicated with priority.Small reducible fat: real finding, but management depends on symptomsBowel, pain or nonreducible: risk of incarceration/strangulation
Hernia defect or neck	measure in millimeters	There is no universal normal cutoff: measure neck/defect, sac, contents, reducibility and behavior at rest/Valsalva/upright position. A small ultrasound-only hernia may not indicate surgery if minimal or asymptomatic.
Inguinal lymph node — short axis	<10 usual; up to 15 may be contextual mm	CT in asymptomatic patients found a mean of 5.4 mm and two standard deviations at 8.8 mm; Node-RADS accepts up to 15 mm for the inguinal region. On ultrasound, morphology matters more than size alone.Green: ≤8.8 mm, oval, fatty hilum, thin cortexYellow: 9-15 mm with preserved morphologyRed: >15 mm or suspicious morphology
Inguinal lymph node — benign morphology	oval, central hilum, cortex <4 mm	Useful criteria: long-axis/short-axis ratio greater than 2, preserved fatty hilum, homogeneous cortex smaller than 4 mm and hilar or absent flow.
Femoral pseudoaneurysm	arterial neck + bidirectional flow	The yin-yang color Doppler sign helps, but the more specific finding is to-and-fro flow in the neck communicating with the artery.Red: neck with to-and-fro flow
Canal of Nuck / female hydrocele	anechoic cyst in the female inguinal canal	May mimic hernia or lymph node. A cystic avascular lesion with posterior enhancement and no bowel continuity favors canal of Nuck hydrocele; look for peritoneal communication and complication.

Classifications and calculators

Interactive assistant — inguinal region

Input	Output	How to use
Complete dynamic exam without finding	Green	Use only when rest, Valsalva/cough and, when needed, upright scanning were documented.
Small, fat-only or equivocal hernia	Yellow	Describe as real/possible finding, measure the neck and correlate symptoms; management may vary.
Femoral hernia, nonreducible bowel or compromise signs	Red	Communicate clinical priority: risk of incarceration, strangulation or obstruction.

Fill in the fields below to generate color reading, differentials and a next-step phrase.

Source: HerniaSurge 2018/2023 / RadioGraphics 2016 / ACR-AIUM-SPR-SRU

Anatomic map of groin hernia

Type	Ultrasound location	Points to report
Indirect inguinal	Lateral to the inferior epigastric vessels; enters through the deep inguinal ring and follows the canal.	Side, neck, content, reducibility, extension to scrotum/labia majora.
Direct inguinal	Medial to the inferior epigastric vessels, in Hesselbach triangle, above the inguinal ligament.	Posterior-wall bulge, neck, content and whether it appears only with strain.
Femoral	Inferior to the inguinal ligament, usually medial to the femoral vein.	Prioritize if pain, bowel, nonreducibility or sac fluid is present.
Recurrent / postoperative	Scan mesh margins and the inferomedial region with dynamic maneuver.	Differentiate recurrence from seroma, hematoma, fibrosis, plug/mesh and lymph node.

Source: RadioGraphics 2016 / EPOS ECR 2023 / AJR 2006

Inguinal lymph node — color reading

Color	Finding	Interpretation
Green	Short axis up to 8.8 mm, oval, long-axis/short-axis ratio >2, fatty hilum, homogeneous cortex <4 mm.	Compatible with reactive/benign node if clinical context matches.
Yellow	Short axis 9-15 mm with preserved hilum, diffuse cortical thickening or inflammatory context.	Common groin gray zone; size alone does not establish malignancy.
Red	Short axis >15 mm, round, absent hilum, eccentric cortex, necrosis/cystic change, interrupted capsule or peripheral/disorganized flow.	Suspicious, especially in skin, vulvar, penile, anal-canal cancer, melanoma, lymphoma or soft-tissue mass.

The inguinal region accepts larger nodes than other territories; therefore morphology and bilateral comparison are decisive.

Source: Bontumasi AJR 2014 / VITA consensus / EPOS ECR 2023

Practical differential diagnosis of a groin mass

Pattern	Possibilities	Alert
Increases with Valsalva or standing	Hernia, round-ligament varices, spermatic-cord varicocele, postoperative recurrence.	Confirm trajectory and relation to vessels/inguinal ligament.
Simple avascular cystic	Canal of Nuck hydrocele, spermatic-cord cyst, simple seroma.	Yellow if septated, painful, infected or with uncertain communication.
Solid oval with hilum	Reactive node, lower-limb dermatopathy, genital/perineal inflammation.	Do not use size alone; follow morphology.
Pulsatile vascular	Femoral pseudoaneurysm, arteriovenous fistula, thrombosed varix.	Spectral Doppler is mandatory before puncture.
Irregular or deep solid	Metastasis, lymphoma, sarcoma, inguinal-canal endometriosis, nerve-sheath tumor.	Consider additional imaging and local oncology pathway.

Source: JSCR 2022 / RadioGraphics 2016 / superficial lymph node ultrasound reviews

Report checklist — inguinal region

Item	Why it matters
Side and pain point	Avoids a generic report when the finding is focal or contralateral.
Rest, Valsalva/cough and upright position when needed	Without dynamic maneuver, an occult hernia may be missed.
Relation to inferior epigastric vessels and femoral vein	Classifies direct, indirect or femoral without difficult abbreviations.
Content and reducibility	Reducible fat, bowel, bladder/ovary, fluid and pain change priority.
Complication	Nonreducible content, thickened bowel, fluid, absent peristalsis, pseudoaneurysm, thrombosis or infection require explicit conclusion.

Source: ACR-AIUM-SPR-SRU / HerniaSurge / RadioGraphics

Cervical region

Brazil: according to the Brazilian College of Radiology scope standard, cervical region includes central and lateral cervical lymph nodes, thyroid bed only after total thyroidectomy, parathyroid beds and main cervical muscle groups. Thyroid, salivary glands and cervical vessels have separate examinations when requested.

Measurements and reference values

Measurement	Usual value	Note
Cervical lymph node — short axis	≤8–10 with benign morphology mm	Size alone is weak: use together with shape, fatty hilum, cortex, necrosis, calcifications, vascularity and clinical context.Green — practical benign consensus: ≤8 mm, oval, preserved hilum, no suspicious signsYellow — borderline or divergent: 8–10 mm or >10 mm with reactive morphologyRed — abnormal/suspicious: >15 mm or any size with necrosis, calcifications, associated absent hilum, peripheral vascularity or growth
Short-axis / long-axis ratio	<0,5	An oval node favors benignity; rounding increases suspicion, especially when combined with loss of hilum or peripheral vascularity.Green: <0.5 and preserved hilumYellow: ≈0.5 in isolationRed: >0.5 with suspicious signs
Suspicious node in thyroid cancer context	≥8–10 mm in the smallest axis	The American Thyroid Association recommends fine-needle aspiration of a suspicious lymph node from 8–10 mm in the smallest axis when the result changes management.Yellow — smaller than 8 mm: may be follow-up if it does not change managementRed — suspicious ≥8–10 mm: consider fine-needle aspiration if clinically relevant
Normal parathyroid gland	usually not visible	When an enlarged parathyroid gland is seen, document location, three measurements, relationship with the thyroid and Doppler if requested.Green: not identified and no focal lesionYellow: compatible hypoechoic lesion, but without laboratory contextRed: compatible lesion in hyperparathyroidism or documented growth
Focal cervical mass	measure in three axes	Describe compartment, side, relationship to skin, muscle, thyroid, salivary glands and vessels; Doppler only when indicated/requested.

Classifications and calculators

Quick calculator — cervical lymph node

Color	Interpretation	Practical criteria
Green	Benign morphology	Short axis ≤8 mm, oval, preserved fatty hilum, thin cortex and hilar or absent vascularity.
Yellow	Gray zone	Short axis 8–10 mm, isolated rounding, poorly seen hilum, reactive enlargement or disagreement between size and morphology.
Red	Suspicious/abnormal	Intranodal necrosis/cyst, calcifications, peripheral or chaotic vascularity, associated absent hilum, irregular margins, conglomerate or growth.

The calculator is assistive. Painful/inflammatory node, age, known cancer, previous thyroidectomy and laterality change the weight of findings.

Source: Ahuja & Ying AJR 2005 / ATA 2015 / AIUM head and neck

Cervical region — examination scope in Brazil

Structure	How to handle in the report	Practical color
Central and lateral cervical lymph nodes	Included; describe location, size and morphology when seen or abnormal.	Green if benign morphology
Thyroid bed after total thyroidectomy	Included only in this context; assess residual tissue, local recurrence and suspicious lymph nodes.	Green if no focal lesion
Parathyroid beds	Assess; report parathyroid gland or muscle group mainly when detectable pathology is present.	Yellow if the finding depends on laboratory tests
Thyroid and salivary glands	In the Brazilian standard, they have separate codes/exams; mention if assessed by specific request or relevant finding.	Yellow because of scope
Doppler and cervical vessels	Doppler is not automatically part of the cervical region; carotid and jugular vessels require their own request/code.	Yellow because of scope

This table avoids mixing cervical region with thyroid, salivary glands or vascular Doppler when the request does not include those items.

Source: Colégio Brasileiro de Radiologia — Normatização de ultrassonografia

Cervical mass or cyst — priority signs

Color	Finding	Communication approach
Green	Typical benign superficial finding, small, without vascular solid component and without documented growth.	Describe and correlate with physical examination.
Yellow	Probable congenital cyst, inflammatory process or indeterminate mass without aggressive signs.	Suggest clinical correlation and cross-sectional imaging/follow-up according to persistence.
Red	Persistent mass in an adult, cystic mass in an adult, vascular solid component, invasion of planes, abscess or pulsatile mass.	Communicate as suspicious/urgent according to context; consider CT, MRI or specialist evaluation.

Ultrasound is useful, but persistent adult neck masses often require specialist clinical evaluation and/or cross-sectional imaging.

Source: ACR Appropriateness Criteria Neck Mass/Adenopathy / AAO-HNS adult neck mass guideline

Documentation checklist — cervical region

Item	Record	Why
Location	Side, level/compartment and relationship to anatomic landmarks.	Allows comparison and planning for aspiration or surgery.
Measurements	Three axes of the mass or lymph node; in a lymph node, emphasize the short axis.	Standardizes follow-up and reduces ambiguity.
Morphology	Shape, hilum, cortex, echogenicity, cystic/necrotic content, calcifications and margins.	More important than size alone.
Doppler	Use for vascularity of localized masses when requested or clinically needed.	Helps, but does not replace B-mode or clinical context.

Avoid short abbreviations in reference reports; prefer “short axis”, “long axis”, “fatty hilum” and “peripheral vascularity”.

Source: AIUM head and neck / ACR-AIUM-SPR-SRU practice parameter

Lymph nodes (general)

Measurements and reference values

Measurement	Usual value	Note
Short axis (normal cervical)	≤ 10 mm	varies by level/region

Classifications and calculators

Lymph node — benign vs suspicious

Sign	Benign	Suspicious/malignant
Shape (short/long)	Oval (< 0.5)	Round (≥ 0.5)
Fatty hilum	Present	Absent
Cortex	Thin and uniform	Thickened/eccentric
Vascularity	Hilar	Peripheral/chaotic

Combine signs; microcalcifications and cystic necrosis raise suspicion (e.g., papillary carcinoma metastasis).

Source: Radiology Key / PubMed (critérios sonográficos)

Obstetric — 2nd/3rd trimester

Measurements and reference values

Measurement	Usual value	Note
Amniotic fluid index (AFI)	5–25 cm	single deepest pocket normal: 2–8 cm
Biometry (BPD, HC, AC, FL)	—	use gestational-age tables (Hadlock/FMF) — no single value

Classifications and calculators

Calculator — amniotic fluid (AFI / deepest pocket)

Range	AFI	Deepest pocket
Oligohydramnios	≤ 5 cm	< 2 cm
Normal	8–18 cm (5–24)	2–8 cm
Polyhydramnios	≥ 24 cm	≥ 8 cm

SMFM prefers the single deepest pocket (fewer false-positive oligohydramnios). Correlate with gestational age, growth and membrane integrity.

Source: Phelan/Moore (AFI) / SMFM / ISUOG

Calculator — fetal Doppler (umbilical/MCA/CPR)

Finding	Reading
Normal umbilical, normal MCA	Routine surveillance.
Umbilical PI >95th or MCA <5th or CPR <5th	Redistribution/resistance: increase surveillance.
Absent umbilical diastole (AEDF)	Advanced placental insufficiency.
Reversed umbilical diastole (REDF)	Severe: fetal medicine; ductus venosus/delivery per GA.

Indices are gestational-age specific (FMF references). Absent/reversed umbilical diastole is the most severe sign.

Source: ISUOG Doppler guidelines / Delphi FGR consensus 2016

Placenta previa and accreta spectrum (PAS)

Situation	Definition/sign	Management
Normally sited placenta	Edge ≥2 cm from internal os.	No restriction by location.
Low-lying placenta	Edge <2 cm from os, not covering.	Reassess in the 3rd trimester.
Placenta previa	Covers the internal os.	Cesarean; plan delivery.
Accreta spectrum (PAS)	Lacunae, loss of clear zone, hypervascularity, bulging (prior cesarean + previa).	Referral center; multidisciplinary team.

Accreta risk rises sharply with previa over a cesarean scar. Document edge-to-os distance and invasion signs.

Source: FIGO PAS 2019 / ISUOG placenta previa & PAS guideline

Cervical length (preterm birth)

Cervix (transvaginal)	Reading
≥ 25 mm	Low preterm birth risk.
15–24 mm	Shortened: consider progesterone/follow-up.
< 15 mm or funneling	High risk: refer; discuss cerclage/pessary.

Measure transvaginally, empty bladder, no excess pressure; use the shortest of 3. 25 mm cutoff in the 2nd trimester.

Source: FMF / SMFM / ISUOG cervical assessment

Fetal Doppler — alert thresholds

Vessel/index	Abnormal	Meaning
Umbilical artery — PI	> 95th centile	increased placental resistance
Middle cerebral artery — PI	< 5th centile	redistribution (brain-sparing)
Cerebroplacental ratio (CPR)	< 10th centile	early placental insufficiency

Indices are gestational-age specific (FMF references). Absent/reversed umbilical end-diastole = severe.

Source: FMF (Ciobanu 2019, UOG)

Elbow

Elbow ultrasound should be read by compartments: anterior, lateral, medial, posterior, nerves and dynamic maneuvers when indicated. Numeric tendon cutoffs vary across series; therefore isolated thickening is yellow, while tear, avulsion, infection, neuropathy with deficit, deep mass and instability are red.

Measurements and reference values

Measurement	Usual value	Note
Minimum elbow protocol	anterior + lateral + medial + posterior	add ulnar nerve, radial nerve, Doppler and dynamic maneuvers when clinically indicated
Technique and comparison	high-frequency linear transducer	scan in long and short axis; compare with the opposite side when measurement, pain or morphology is borderline
Common extensor tendon — thickness	< 4,2 mm	green if fibrillar and without focal pain; 4.2 mm or more is yellow because it is a practical cutoff, not a universal standalone consensus
Common extensor tendon — cross-sectional area	< 32 mm²	32 mm² or more supports lateral epicondylalgia when there is hypoechogenicity, fissure, calcification, cortical irregularity or pain
Common flexor-pronator tendon	no universal cutoff	use thickness, echotexture, residual fibers, enthesopathy, Doppler and contralateral comparison
Ulnar nerve at cubital tunnel — cross-sectional area	< 8 verde · 8–9,9 amarelo · ≥10 vermelho mm²	10 mm² or more is a widely used practical cutoff; confirm with symptoms, morphology, elbow-to-forearm ratio and nerve conduction when needed
Elbow-to-forearm ulnar nerve area ratio	< 1,3 verde · 1,3–1,49 amarelo · ≥1,5 contextual	do not use alone; it supports focal swelling when absolute area and symptoms agree
Olecranon bursa	normally collapsed or not visible	any distension is contextual; thick wall, debris, gas, hyperemia, wound or fever raise it to red
Elbow effusion/synovitis	no single universal number	effusion is yellow; with trauma, mechanical locking, fever, crystals, inflammatory arthritis or intense Doppler it may be red
Distal biceps and triceps	assess continuity, gap and retraction	complete tear, avulsion or traumatic gap is red; tendinopathy/partial tear is yellow
Elbow ligaments	dynamic stress when indicated	assess the lateral complex and ulnar collateral ligament; dynamic opening, avulsion or clinical instability is red

Classifications and calculators

Interactive assistant — elbow ultrasound

Color	When to use	Teaching action
Green	Measurement below practical cutoff and preserved morphology	Record the compartment protocol and comparison when performed
Yellow	Thickening, small effusion, tendinopathy, simple bursitis, mild Doppler or finding without universal numeric consensus	Describe morphology, pain, opposite side and limitation; avoid absolute conclusion from an isolated number
Red	Complete tear, avulsion, infection, neuropathy with deficit, deep mass, mechanical locking or dynamic instability	Measure extent/gap/retraction, document Doppler/dynamics and recommend urgent correlation according to context

The assistant uses colors to separate consensus normality, gray zone and clearly abnormal findings. It does not replace clinical judgment, radiographs, MRI or electrodiagnostic testing when the question is bone, deep intra-articular or neurophysiologic.

Source: AIUM/ACR/SPR/SRU 2017; ESSR; peripheral nerve ultrasound consensus

Anatomic roadmap by compartment

Compartment	Required structures	Attention point
Anterior	Anterior recess, humeroradial/humeroulnar joint, distal biceps, brachialis, vessels and nerves when indicated	Effusion, synovitis, loose body, bicipitoradial bursa and distal biceps tear
Lateral	Lateral epicondyle, common extensor tendon, lateral ligament complex, radial head/neck and radial nerve	Lateral epicondylalgia, partial/complete tear, calcification, fissure and varus instability
Medial	Medial epicondyle, common flexor-pronator tendon, ulnar collateral ligament and ulnar nerve at cubital tunnel	Assess nerve flexion/extension and valgus stress when indicated
Posterior	Triceps, olecranon, olecranon bursa and posterior recess	Bursitis, triceps tear, posterior impingement, osteophyte and loose body
Nerves and dynamics	Ulnar nerve, radial nerve and posterior interosseous branch according to symptoms	Cross-sectional area, proximal/distal caliber, focal compression, subluxation and snapping triceps

Source: AIUM/ACR/SPR/SRU 2017; ESSR elbow technical guideline

Tendons and ligaments — color reading

Structure	Green	Yellow	Red
Common extensor tendon	fibrillar, thin, no focal pain	thickness ≥4.2 mm, area ≥32 mm², hypoechogenicity, calcification or small fissure	high-grade/complete tear, avulsion or traumatic gap
Common flexor-pronator tendon	fibrillar and symmetric	tendinopathy, enthesopathy, calcification or partial tear	high-grade/complete tear or medial avulsion
Distal biceps	continuity to radial tuberosity	tendinopathy, bicipitoradial bursitis or partial tear	complete tear, retraction or avulsion
Triceps	fibrillar, preserved insertion	tendinopathy, enthesophyte or partial tear	complete tear, avulsion or extensor deficit
Ulnar collateral ligament and lateral complex	continuous and without dynamic opening	thickening, pain and mild/contextual laxity	avulsion, dynamic opening, symptomatic throwing athlete or clinical instability

Source: ESSR; AIUM/ACR/SPR/SRU 2017

Nerves, Doppler and dynamic maneuvers

Item	Green	Yellow	Red
Ulnar nerve — cross-sectional area	<8 mm² and fascicular	8-9.9 mm² or elevated ratio without deficit	≥10 mm², focal compression, hourglass or motor deficit
Ulnar nerve dynamics	stable during flexion/extension	asymptomatic subluxation or mild snapping	symptomatic dislocation, painful snapping triceps or neurologic deficit
Doppler	no hyperemia	mild/moderate hyperemia in tendinopathy, bursa or synovitis	intense hyperemia with fever, wound, complex bursa or possible septic arthritis
Radial nerve or posterior interosseous branch	fascicular, no compression	enlargement or pain without deficit	motor deficit, compression by mass/cyst or suspected denervation

Source: ESSR; peripheral nerve ultrasound consensus

Useful elbow differential diagnoses

Dominant symptom	Common possibilities	What ultrasound should look for
Lateral pain	lateral epicondylalgia, lateral complex injury, radiocapitellar osteoarthritis, radial nerve	common extensor tendon, calcifications, cortex, ligament and posterior interosseous branch
Medial pain	medial epicondylalgia, ulnar collateral ligament, ulnar nerve, throwing athlete	common flexor-pronator tendon, valgus stress, ulnar nerve area and dynamics
Posterior pain or swelling	olecranon bursitis, gout, infection, triceps, posterior impingement	bursa, wall, debris, Doppler, triceps and posterior recess
Trauma with pop	distal biceps tear, triceps tear, avulsion, occult fracture	tendon continuity, gap, retraction, effusion and cortex; radiograph if bone concern
Paresthesia or weakness	ulnar neuropathy, radial neuropathy or compression by mass/cyst	cross-sectional area, caliber, focal compression, dynamics, mass and denervated muscles
Stiffness, locking or effusion	synovitis, loose body, crystals, osteoarthritis, infectious arthritis	recesses, Doppler, erosions, visible loose body and systemic warning signs

Source: AIUM/ACR/SPR/SRU 2017; ESSR

Teaching checklist for the elbow report

Step	Record
1. Indication and side	lateral, medial, posterior or anterior pain, trauma, neuropathy, rheumatology, postoperative setting or procedure
2. Compartments	anterior, lateral, medial and posterior; state if any was not assessed
3. Tendons and ligaments	thickness, echotexture, residual fibers, calcification, gap, retraction, enthesis and dynamic stress
4. Nerves and Doppler	ulnar nerve, radial nerve/posterior interosseous branch, cross-sectional area, dynamics and hyperemia
5. Limitations	ultrasound does not replace radiographs/MRI for deep bone, cartilage, deep intra-articular loose body or complex instability

Source: AIUM/ACR/SPR/SRU 2017; ESSR

Skin / subcutaneous

Classifications and calculators

Superficial lesions — typical appearance

Lesion	US appearance
Lipoma	Oval, compressible, iso/hyperechoic, linear septa parallel to skin, minimal vascularity
Epidermal/sebaceous cyst	Well-defined subcutaneous, variable content (anechoic→solid), "submarine sign", posterior enhancement

US for lipoma: sens. ~95% / spec. ~94%; epidermal cyst: sens. ~80% / spec. ~95%. Red flags (solid > 5 cm, chaotic vascularity, growth) → work up for tumor.

Source: SRU Consensus 2021 (Radiology) / KJR

Lipedema / lymphedema

Ultrasound does not establish the diagnosis of lipedema (which is clinical), but it measures the subcutis, shows the fat pattern and helps differentiate from lymphedema (fluid/cobblestone) and edema of other causes. Always compare both sides and the thigh→ankle gradient.

Measurements and reference values

Measurement	Usual value	Note
Subcutaneous thickness — thigh (comparison)	no universal cutoff mm	Highly BMI-dependent; what matters is symmetry and the thigh→ankle gradient. In lipedema the subcutis is disproportionately thick, symmetric and without fluid.
Dermal thickness	≤ ~2 mm	Dermal thickening with subcutaneous fluid favors lymphedema, not pure lipedema.usual: ≤2 mmborderline: 2–3 mmthickened (lymphatic component): >3 mm
Subcutaneous fluid (anechoic clefts/lakes)	absent in pure lipedema	"Cobblestone" or anechoic lakes pattern indicates a lymphatic component (lymphedema or lipolymphedema).

Classifications and calculators

Calculator — lipedema support (clinical + US)

Color	Practical reading
Green	Pattern consistent with lipedema: diffuse symmetric hypoechoic fat, no fluid; foot spared; negative Stemmer.
Yellow	Probable but with overlap/advanced stage — document and correlate clinically.
Red	Fluid/lymphedema signs (clefts, lakes, foot involvement, positive Stemmer): lipolymphedema — refer for lymphatic therapy.

Lipedema is a clinical diagnosis. There is no single validated ultrasound classification; US documents the subcutis and rules out lymphedema.

Source: Consenso europeu de lipedema 2020 (Phlebology) / Diretriz S1 alemã 2017

Clinical stages of lipedema

Stage	Skin surface	Subcutis
I	Smooth, regular	Thickened and uniform, homogeneous hypoechoic fat
II	Uneven, "mattress", palpable nodules	More evident nodules and septa
III	Deforming fat lobules	Large lobules, contour distortion
IV	Lipedema + lymphedema (lipolymphedema)	Fat + fluid/fibrosis; foot may be involved

Clinical stage refers to skin/tissue; pain, fatigue and functional impact do not necessarily follow the stage. Types 1–5 describe distribution (hip, thigh, calf, arms).

Source: Consenso europeu 2020 / Wold-Allen 1951

Calculator — lymphedema staging (ISL)

Color	Practical reading
Green	No US signs of lymphedema (no fluid, normal dermis).
Yellow	Early/reversible edema: fine clefts, positive Stemmer, still pitting.
Red	Established: anechoic lakes, thickened dermis, fibrosis (non-pitting).

US complements the clinical exam; lymphoscintigraphy remains the standard to confirm lymphatic dysfunction.

Source: ISL Consensus 2020 (Lymphology)

ISL lymphedema stages

Stage	Clinical	Typical US
0	Latent/subclinical (no visible edema)	No fluid; may show mild thickening
I	Edema reducing with elevation (pitting)	Fine subcutaneous clefts
II	Does not reduce spontaneously; increasing fibrosis	Anechoic lakes, thickened dermis
III	Elephantiasis, skin changes	Dense fibrosis, variable fluid

ISL staging is clinical; US helps grade fluid/fibrosis and monitor decongestive therapy.

Source: ISL Consensus 2020

Lipedema vs lymphedema — how to tell apart

Feature	Lipedema	Lymphedema
Symmetry	Bilateral and symmetric	Often asymmetric/unilateral
Foot/dorsum	Spared (cuff sign)	Involved
Stemmer sign	Negative	Positive
Pressure pain	Typical	Less common
Subcutaneous fluid on US	Absent	Present (cobblestone/lakes)
Dermal thickening	Absent/mild	Present

Coexistence (lipolymphedema) is common in advanced stages. When in doubt, combine findings and consider lymphoscintigraphy.

Source: Consenso europeu 2020 / ISL 2020

Echocardiography (transthoracic)

Measurements and reference values

Measurement	Usual value	Note
LV ejection fraction (LVEF)	≥ 53 %	normal M 52–72 · F 54–74
LV end-diastolic diameter	M 42–58 · F 38–52 mm
Septum / posterior wall (diastole)	6–10 mm
Left atrium — diameter	M ≤ 40 · F ≤ 38 mm	indexed volume ≤ 34 mL/m²
Aortic root (sinuses of Valsalva)	M ≤ 40 · F ≤ 36 mm	ideally index to body surface area

Transcranial Doppler / ONSD

Measurements and reference values

Measurement	Usual value	Note
MCA — mean velocity	< 120 cm/s	> 120 suggests vasospasm; > 200 critical
Optic nerve sheath diameter (ONSD)	≤ 5 mm	> 5.8 mm suggests raised ICP

Classifications and calculators

Lindegaard ratio (MCA/ICA) — vasospasm

Ratio	Interpretation
< 3	Hyperemia / normal
3–4,5	Mild vasospasm
4,5–6	Moderate vasospasm
> 6	Severe vasospasm

Source: J Vasc Surg / StatPearls

Ocular / ophthalmic

Use a no-pressure technique, abundant gel and an ocular preset when available. If open globe is suspected, do not compress the eye and prioritize ophthalmology or emergency care; this section is teaching support and does not replace ophthalmologic examination.

Measurements and reference values

Measurement	Usual value	Note
Safe technique — scan through the eyelid	abundant gel, linear probe, no direct pressure, ocular preset	The probe should float on the gel. In trauma, severe pain or suspected perforation, the priority is not to compress the globe.safe: no pressure + ocular presettechnical limitation: no ocular preset or poor windowdo not compress: suspected open globe
Minimum sweep to learn anatomy	transverse and longitudinal planes, resting eye and gentle eye movements	Identify the lens, vitreous, retina, posterior wall, optic nerve and retrobulbar space before searching for disease.
Optic nerve sheath — adult	≤ 5,0 mm	Measure 3 mm behind the retina/posterior globe wall; ideally measure both eyes and interpret with the neurologic context.consensus normal: ≤5,0 mmborderline or divergent: >5,0–5,7 mmhigh risk for raised intracranial pressure: ≥5,8 mm
Optic nerve sheath — child	≤4.5 in 1–15 years; ≤4.0 under 1 year mm	Pediatric thresholds vary; use as screening, not as a standalone diagnosis of raised intracranial pressure.consensus normal: ≤4.5 mm child; ≤4.0 mm infantborderline: up to ~0.5 mm above cutofflikely abnormal: clearly above cutoff + clinical context
Optic disc elevation	≤ 0,6 mm	Elevation above 0.6 mm favors papilledema in the right context; optic disc drusen can mimic pseudopapilledema.no relevant elevation: <0,4 mmgray zone: 0,4–0,6 mmsuspicious for papilledema: >0,6 mm
Adult ocular axial length	~22–24,5 mm	Varies with refraction, population and method. Very long values suggest axial myopia; short values may occur in hyperopia or small eyes.usual adult range: 22–24,5 mmoutside mean, correlate refraction: 20,5–21,9 ou 24,6–26,4 mmmarkedly outside range: <20,5 ou ≥26,5 mm
Normal posterior segment	anechoic vitreous; thin continuous retina on posterior wall; optic disc as reference	Dynamic eye movement helps separate true membranes from mobile vitreous echoes.
Intraocular mass — required measurements	base, height, location, reflectivity, shadowing and vascularity when indicated	Solid mass, growth, calcification in a child or associated detachment requires specialist ophthalmologic evaluation.no mass: regular wallindeterminate lesion: document and comparehigh risk: solid vascular mass, calcified lesion in a child, or growth

Classifications and calculators

Interactive assistant — ocular ultrasound

Output	Color	Reading
Likely normal	Green	No warning sign, measurements within range and posterior segment without pathologic membranes.
Caution / indeterminate	Yellow	Borderline measurement, mobile vitreous echoes, posterior vitreous detachment, limited technique or trauma indication without open-globe signs.
Urgent	Red	Suspected open globe, retinal detachment, foreign body, absent central retinal artery flow, retrobulbar hematoma, lens dislocation or likely raised intracranial pressure.

The Clear button resets the calculation. The output is a teaching triage to standardize reasoning and communication; ocular emergencies still require specialist evaluation.

Source: StatPearls / ACEP Sonoguide / EyeWiki

Anatomic map for patients and learners

Structure	How it appears	Why it matters
Lens	Biconvex structure just behind the iris; normally centered.	Subluxation or dislocation may occur in trauma and affect vision.
Vitreous	Dark/anechoic content filling most of the eye.	Mobile echoes suggest blood, inflammation or vitreous degeneration.
Retina	Thin line along the posterior wall; when detached, it becomes a thicker membrane tethered to the optic disc.	Retinal detachment is an emergency, especially if the macula is still attached.
Choroid	Deep vascular layer; detachments are often convex and do not cross the optic disc.	Helps differentiate choroidal detachment from retinal detachment.
Optic nerve and its sheath	Dark structure behind the globe; the sheath is measured 3 mm behind the posterior wall.	Enlargement may accompany raised intracranial pressure.
Central retinal artery	Doppler flow within the optic nerve entering the eye.	Absent or markedly reduced flow in the right context suggests arterial occlusion.

Source: EyeWiki / StatPearls / ACEP Sonoguide

Safe technique step by step

Step	Do	Avoid
Before touching	Ask about penetrating trauma, recent surgery, severe pain or globe deformity.	Pressure if open globe is suspected.
Prepare	Thick gel layer over the closed eyelid and linear probe.	Dry contact or compression to “improve” the image.
Set up	Ocular preset/low mechanical and thermal indices when available.	Unnecessary high output.
Sweep	Horizontal and vertical planes, with gentle eye movements to assess mobility.	Concluding without quadrant assessment or dynamic motion.
Measure	Optic nerve sheath 3 mm behind the retina; axial length along the visual axis when indicated.	Oblique measurement or off-axis image.

Source: ACEP Sonoguide / University of Iowa EyeRounds / StatPearls

Retina, vitreous and choroid — how to differentiate

Finding	Ultrasound clue	Suggested action
Normal posterior segment	Dark vitreous, no membrane; retina attached to wall.	Correlate with clinical examination.
Vitreous hemorrhage	Heterogeneous mobile echoes, more evident with high gain and eye movement.	Assess hidden retina; guide ophthalmology according to context.
Posterior vitreous detachment	Thin very mobile membrane, not tethered to the optic disc and may cross the midline.	Differentiate from retina; urgent return if flashes, dark curtain or worsening.
Retinal detachment	Thicker membrane, tethered to the optic disc, often V-shaped or funnel-shaped.	Urgent ophthalmologic evaluation; macula-on is more time-sensitive.
Choroidal detachment	Thick convex membranes, may appear “kissing”, spare the optic disc.	Correlate trauma, surgery, hypotony or inflammation; specialist evaluation.

Source: ACEP Sonoguide / StatPearls / EyeWiki

Emergencies and warnings in ocular ultrasound

Situation	Useful findings	Practical message
Open globe / globe rupture	Irregular contour, abnormal anterior chamber, extruded contents; foreign body may be present.	Do not compress. Stop scanning if suspicion is high.
Intraocular foreign body	Very echogenic focus with shadowing or reverberation.	Treat as penetrating trauma until proven otherwise.
Lens dislocation	Lens displaced into vitreous or anterior chamber, outside the expected axis.	Associate with trauma, connective-tissue disorder or surgery.
Retrobulbar hematoma	Collection behind the globe, proptosis; globe may look “pointed”.	Orbital emergency if pain, proptosis or vision loss is present.
Central retinal artery occlusion	Absent or markedly reduced flow; sometimes an echogenic embolic focus near the disc.	Short therapeutic window; immediate communication.
Orbital cellulitis / abscess	Soft-tissue thickening, collection, restricted motion, pain.	Ultrasound helps, but computed tomography/ophthalmology may be needed.

Source: ACEP Sonoguide / StatPearls

Optic nerve sheath and papilledema — color reading

Measurement	Green	Yellow	Red
Adult	≤5,0 mm	>5,0–5,7 mm	≥5,8 mm
Child 1–15 years	≤4,5 mm	4,6–5,0 mm	>5,0 mm + clínica
Under 1 year	≤4,0 mm	4,1–4,5 mm	>4,5 mm + clínica
Optic disc elevation	<0,4 mm	0,4–0,6 mm	>0,6 mm

These cutoffs do not replace neurologic evaluation. Hydration, hypercapnia, technique, image axis and ocular disease may change the measurement.

Source: ACEP Sonoguide / StatPearls / revisão de bainha do nervo óptico

Biometry and masses — what to document

Use	Document	Watch for
Ocular biometry	Axial length, method, right/left eye and measurement quality.	Inter-eye difference and refraction.
Opaque media	Dense cataract, hemorrhage or opacity blocking fundoscopy.	Ultrasound assesses the hidden retina but does not replace complete examination.
Melanocytic or solid mass	Base, height, shape, reflectivity, shadowing, subretinal fluid and vascularity.	Growth or activity signs require a specialist.
Child with mass/calcification	Echogenic intraocular mass, calcification or associated detachment.	Consider retinoblastoma until proven otherwise.

Source: EyeWiki / Ophthalmologic ultrasound reviews

Teaching checklist for the ocular report

Item	Question the report should answer
Safety/technique	Was it transpalpebral, no pressure, with limitation from pain/trauma?
Globe	Are contour, volume and anterior chamber preserved?
Lens	Is it centered or is there subluxation/dislocation?
Vitreous	Is it anechoic or are there mobile echoes compatible with blood/inflammation?
Retina/choroid	Is there a membrane? Is it tethered to the optic disc or does it spare the disc?
Optic nerve	Were sheath and disc measured when there was a neurologic indication?
Doppler	Was central retinal artery flow assessed when acute vision loss was present?
Conclusion	Does the conclusion separate normal, indeterminate and urgent, with an objective recommendation?

Source: StatPearls / ACEP Sonoguide / EyeWiki

Bedside POCUS / ICU / emergency

POCUS answers focused bedside questions and should be integrated with physical exam, vital signs, laboratory data, evolution and local protocol. Green = reassuring finding in completed fields; yellow = borderline, incomplete or context-dependent; red = critical finding, especially with instability, trauma or cardiac arrest.

Measurements and reference values

Measurement	Usual value	Note
Inferior vena cava — diameter and respiratory variation	≤2,1 cm + >50%	Echocardiographic pattern for estimating right atrial pressure during spontaneous breathing; do not use alone to decide fluids, especially with mechanical ventilation, athletes, pulmonary hypertension or right ventricular dysfunction.low or normal right-sided pressure: ≤2,1 cm e colapso >50%intermediate or context-dependent: discordant diameter and collapseprobable congestion in the acute setting: >2,1 cm e colapso <50% + clínica
Inferior vena cava — distensibility with positive pressure	≥18 %	With positive-pressure ventilation, high variation may suggest fluid responsiveness in some studies, but depends on rhythm, tidal volume, pressure, lung compliance, abdominal pressure and right ventricular function.low variation: <18%possible responsiveness: ≥18%do not use alone in severe shock: integrate heart and lung
FAST/eFAST — minimum windows	pericardium, right upper quadrant, left upper quadrant, pelvis, pleurae and lung sliding	The goal is to detect pericardial, pleural or intraperitoneal free fluid and pneumothorax. In unstable trauma, any positive finding changes resuscitation and team priorities.complete and negative: all windows assessed without fluid or pneumothoraxincomplete or serial: poor window, equivocal finding or repeatpositive with instability: free fluid, hemothorax, pneumothorax or pericardium
Pericardial effusion — diastolic thickness	<1 / 1–2 / >2 cm	Teaching classification: small, moderate and large. Severity is not determined by thickness alone: right-chamber collapse, plethoric inferior vena cava, exaggerated respiratory variation and instability suggest tamponade.no effusion: pericardium without fluidsmall or moderate and stable: <2 cm sem colapsohigh risk: >2 cm, hemopericárdio ou sinais de tamponamento
Lung — B-lines	≥3 per intercostal space or zone	Fewer than three B-lines in one space is usually normal. Diffuse bilateral pattern favors edema; focal pattern favors pneumonia, contusion, infarction, atelectasis or pleural disease.aerated lung: 0–2interstitial syndrome: ≥3diffuse edema with respiratory failure: bilateral pattern + clinical context
Pneumothorax — main signs	absent sliding, absent B-lines, barcode sign and lung point	Present lung sliding excludes pneumothorax at that point. Lung point is highly specific in the correct context; absent sliding alone is not specific.sliding present: pneumothorax excluded at that pointisolated absent sliding: may be atelectasis, apnea, mainstem intubation or adhesionprobable pneumothorax: lung point or barcode sign + clinical context
Abdominal free fluid in trauma	any free fluid is FAST positive	FAST is most useful in unstable patients. In stable patients, a negative FAST does not exclude abdominal injury; consider computed tomography, observation and serial exam according to protocol.no fluid in assessed windows: FAST negative in completed fieldstrace or limited window: repeat or complementfree fluid with instability: activate trauma/shock protocol
Abdominal aorta in POCUS — largest outer diameter	<3,0 cm	Measure outer wall to outer wall, sweeping proximal, mid and distal aorta to the bifurcation. Aneurysm is defined from 3.0 cm; 2.5–2.9 cm remains ectatic/borderline.no aneurysm if complete exam: <2,5 cmectasia or comparison zone: 2,5–2,9 cmabdominal aneurysm: ≥3,0 cm
Proximal venous compression for thrombosis	walls should touch	Common femoral, femoral/deep femoral junction and popliteal veins should fully collapse with perpendicular compression. A noncompressible proximal vein is abnormal; incomplete exam should be repeated or complemented according to risk.compressible: walls touch at assessed pointsindeterminate: pain, obesity, oblique compression or incomplete windownoncompressible: compatible with proximal deep venous thrombosis
Semiquantitative lung ultrasound score	0–36	When the service uses 12 zones, each zone receives 0 to 3: A-lines or up to two B-lines, three or more B-lines, coalescent B-lines and consolidation. Severity cutoffs vary by population; use mainly for trend and loss of aeration.low in completed fields: 0–5intermediate / follow trend: 6–15high in respiratory context: >15 + clínica
Bedside guided procedures	safe window + depth + vessels	For vascular access, thoracentesis, paracentesis, pericardiocentesis and drainage, record target, depth, needle path, structures to avoid, Doppler when useful and immediate complications.

Classifications and calculators

Calculator — diaphragm function (POCUS)

Parameter	Normal	Dysfunction
Thickening fraction	≥ 30%	< 20%
Expiratory thickness	≥ 1,5 mm	< 1,5 mm (atrofia)
Excursion (quiet breathing)	≥ 10–15 mm	< 10 mm

TF% = (inspiratory − expiratory thickness)/expiratory. Useful in difficult weaning, unexplained dyspnea and suspected phrenic palsy. Low effort on mechanical ventilation reduces TF without disease.

Source: Boon (Muscle Nerve) / ATS diaphragm US reviews

Trauma — FAST/eFAST and AAST grading

Item	Reading
Negative FAST	No free fluid in windows; does not exclude injury — repeat/serial if unstable.
Positive FAST + unstable	Free fluid → laparotomy; changes resuscitation priority.
AAST I–II (spleen/liver/kidney)	Superficial laceration/small hematoma; often non-operative management.
AAST IV–V	Deep laceration, devascularization or hilar injury; high surgical/embolization risk.

US does not grade parenchymal injury well — AAST grading is CT/surgical. eFAST detects free fluid and pneumothorax; use CEUS/CT to characterize solid organs.

Source: AAST Organ Injury Scale (rev. 2018) / ACEP eFAST

Interactive assistant — acute POCUS, FAST/eFAST, inferior vena cava, thorax, aorta and thrombosis

Output	Color	Reading
POCUS without critical finding in completed fields	Green	Lung sliding present, FAST negative in assessed windows, aorta below 3.0 cm if scanned, compressible veins if tested and no selected alert.
Borderline, incomplete or context-dependent POCUS	Yellow	Intermediate inferior vena cava, unassessed window, trace fluid, small/moderate stable pericardial effusion, focal B-lines, ectatic aorta, indeterminate venous compression or need for serial repeat.
POCUS with critical or relevant abnormal finding	Red	Free fluid in trauma/shock, hemothorax, probable pneumothorax, tamponade, markedly reduced cardiac function, absent cardiac activity, overloaded right ventricle, aorta >=3.0 cm or noncompressible proximal vein.

The calculator organizes findings for rapid communication. In emergency care, the result must be confirmed on the monitor, in the patient and in the institutional protocol before any invasive decision.

Source: ACEP POCUS guidelines / ACEP Sonoguide / ASE POCUS nomenclature

Interactive calculator — pleural effusion in POCUS

Method	How to measure	Formula / use
Balik — supine	Maximum pleural separation in millimeters, in the largest free pocket.	Estimated volume = 20 × separation in millimeters. Useful at bedside; meaningful average error, does not replace measured drainage.
Goecke 1 — sitting	Craniocaudal effusion height in centimeters.	Estimated volume = height × 90. Simple, but less complete than adding the subpulmonary distance.
Goecke 2 / Hassan — sitting	Lateral height + distance between lung base and diaphragm, in centimeters.	Estimated volume = (height + distance) × 70. Good correlation in drainage studies, still an estimate.
Do not use formula alone	Septations, internal echoes, pleural nodules, trauma, fever or marked dyspnea.	Color should be driven by complexity and clinical context; large volume does not define etiology.

Document side, patient position, window used, measurement used by the formula, and whether the fluid is free or loculated.

Source: Balik 2006 / Ibitoye 2018 / Hassan 2017 / EFSUMB / ERS

FAST/eFAST — protocol and color reading

Window	What to look for	Color reading
Pericardium	Fluid between heart and pericardium, mainly in subxiphoid or parasternal window.	Green if absent; red with penetrating trauma, instability or tamponade signs.
Right upper quadrant	Hepatorenal space, inferior liver tip and right subdiaphragmatic/pleural region.	Free fluid is positive; in shock/trauma it should be communicated immediately.
Left upper quadrant	Perisplenic, left subdiaphragmatic and left pleural regions.	More difficult window; fluid around the spleen or above the diaphragm is relevant.
Pelvis	Fluid posterior to bladder, cul-de-sac or rectovesical space.	May be the first positive window; empty bladder reduces sensitivity.
eFAST thorax	Hemothorax above the diaphragm and pneumothorax by absent sliding, barcode sign or lung point.	Lung point or hemothorax in unstable trauma is red.
Serial exam	Repeat after deterioration, intervention, repositioning or initially limited window.	Yellow when incomplete; green or red depends on repeat exam.

Source: ACEP FAST Sonoguide / trauma POCUS reviews

Inferior vena cava — teaching interpretation

Finding	Color	How to use
≤2,1 cm + colapso >50%	Green	Suggests low/normal right atrial pressure during spontaneous breathing if image and context are adequate.
Discordant or intermediate	Yellow	Do not decide fluids by the inferior vena cava alone; look for hyperdynamic/reduced heart, B-lines, perfusion, lactate and clinical response.
>2,1 cm + colapso <50%	Red if unstable	Suggests elevated right-sided pressure/congestion; in shock consider obstruction, tamponade, right failure, pulmonary embolism or fluid overload.
Distensibilidade ≥18% em pressão positiva	Yellow	May suggest fluid responsiveness in some conditions; loses reliability with low tidal volume, arrhythmia, abdominal hypertension or right-sided dysfunction.

Source: ASE right-heart guideline / critical-care IVC studies

Pericardium and tamponade

Finding	Interpretation	Priority
No pericardial fluid	Reassuring for the question “is there effusion?”	Green if the window is adequate.
Small effusion	Less than 1 cm; measure and correlate symptoms, malignancy, uremia, postoperative state or inflammation.	Yellow unless penetrating trauma or deterioration.
Moderate effusion	Between 1 and 2 cm; look for right-chamber collapse and plethoric inferior vena cava.	Yellow or red depending on stability.
Large, complex or hemopericardium	Greater than 2 cm, clots or trauma increase risk.	Red in the acute setting.
Tamponade signs	Right ventricular diastolic collapse, right atrial systolic collapse, plethoric inferior vena cava or compatible instability.	Immediate communication.

Source: ACEP cardiac tamponade / ASE POCUS nomenclature

Lung POCUS — useful profiles

Profile	Findings	Practical reading
A-lines with sliding	Horizontal artifacts and sliding pleura.	Aerated lung at that point; may be normal or obstructive depending on context.
Diffuse bilateral B-lines	Three or more B-lines per space/zone in several zones.	Favors interstitial edema; red with severe respiratory failure.
Focal B-lines or consolidation	Asymmetric pattern, irregular pleura, dynamic air bronchogram or subpleural consolidation.	Consider pneumonia, contusion, atelectasis, infarction or pleural disease.
Probable pneumothorax	Absent sliding with absent B-lines, barcode sign and/or lung point.	Red with trauma, ventilation or instability.
Pleural effusion	Anechoic or complex fluid above the diaphragm.	Use volume calculator as an estimate; complexity and symptoms define urgency.

Source: ACEP Lung Sonoguide / BLUE protocol / lung ultrasound recommendations

Aorta and venous thrombosis in shock/dyspnea POCUS

Question	Green	Yellow	Red
Abdominal aorta	<2.5 cm and complete outer-wall-to-outer-wall sweep.	2.5–2.9 cm: ectatic/borderline; compare and document technique.	>=3.0 cm: aneurysm. Pain, hypotension or syncope makes the finding critical.
Suspected dissection/rupture	No indirect signs and low clinical concern if exam is complete.	Exam limited by gas/pain: do not exclude vascular catastrophe.	Flap, hematoma, free fluid, severe pain or shock: vascular/emergency pathway.
Proximal venous thrombosis	Femoral and popliteal veins compressible at assessed points.	Incomplete compression, pain, obesity, duplicated vein or partial window.	Noncompressible proximal vein or visible thrombus: compatible with deep venous thrombosis.
Pulmonary embolism integration	No thrombosis and no right ventricular dilation lowers probability but does not exclude.	Dyspnea with discordant findings requires clinical protocol.	Proximal thrombosis + dilated right ventricle/shock increases concern for relevant pulmonary embolism.

Vascular POCUS is excellent for focused questions, but a limited exam does not replace complete vascular Doppler or CT when suspicion remains high.

Source: ACEP Aorta Sonoguide / ACEP DVT Sonoguide / ACEP POCUS guidelines

Lung score — loss of aeration by zone

Zone score	Ultrasound finding	Reading
0	A-lines or up to two B-lines with sliding.	Preserved aeration at that point.
1	Three or more well-spaced B-lines.	Mild aeration loss / early interstitial syndrome.
2	Coalescent B-lines or partial white lung.	Moderate to marked loss; follow trend and distribution.
3	Tissue-like pattern/subpleural consolidation.	Severe aeration loss; correlate pneumonia, atelectasis, contusion, infarction or severe edema.

The 0–36 sum assumes 12 zones. Absolute cutoffs vary by population; in emergency/ICU care, serial trend is often more useful than a single measure.

Source: ACEP Lung Sonoguide / lung ultrasound score literature

Guided procedures — safety checklist

Procedure	Before puncture	During/after
Vascular access	Identify vein and artery, compressibility, thrombus, depth and free path.	Prefer needle-tip visualization; confirm flow/position according to protocol.
Thoracentesis	Confirm free fluid, diaphragm, lung, depth and intercostal vessels when possible.	Reassess lung sliding and complications after the procedure.
Paracentesis	Map ascites, bowel loops, bladder, epigastric vessels and wall thickness.	Record site, depth, free/loculated fluid and tolerance.
Pericardiocentesis	Define largest pocket, relationship with liver/lung/coronaries and safest window.	In tamponade, communication and trained team are priority; POCUS guides but does not replace institutional protocol.
Abscess or collection drainage	Confirm fluid, septations, gas, vessels and deep structures.	Document path, aspirated content and whether immediate complication occurred.

Source: ACEP POCUS guidelines / ACEP procedural ultrasound guidance

Undifferentiated shock — RUSH-style integration

Question	POCUS finding	Interpretation
Pump	Markedly reduced ventricular function, absent activity or effusion with tamponade.	Consider cardiogenic shock, arrest without effective activity or obstructive shock.
Tank	Very small/collapsible inferior vena cava, free fluid, aortic aneurysm or pulmonary congestion.	Separate hypovolemia, hemorrhage, congestion and vascular causes.
Pipes	Deep venous thrombosis, dilated right ventricle, pneumothorax or aortic aneurysm.	Raises suspicion for pulmonary embolism, obstruction or vascular catastrophe.
Lung	Diffuse B-lines, consolidation, effusion or absent sliding.	Helps choose between fluids, vasopressor, ventilation and drainage according to protocol.

Source: ACEP POCUS guidelines / RUSH literature / BLUE protocol

POCUS documentation checklist

Item	What to document
Clinical question	Shock, trauma, dyspnea, arrest, sepsis, procedure or serial reassessment.
Technique	Probe, obtained windows, patient position, ventilation and limitations.
Positive and negative findings	Mention free fluid, pericardium, lung sliding, B-lines, cardiac function, inferior vena cava, aorta and venous compression when assessed.
Measurements and calculations	Inferior vena cava diameters, collapsibility/distensibility index, effusion thickness, mitral variation, aorta, lung score and pleural effusion estimate when useful.
Clinical integration	State whether the finding changes immediate management, requires complementary imaging, serial repeat or urgent communication.

Source: ACEP POCUS guidelines / ASE POCUS nomenclature

Lung / thorax (POCUS)

International: pleural guidance agrees that ultrasound is essential to locate fluid, guide procedures and identify complexity, but there is no single universal formula for volume. Use the calculator as an estimate, and document patient position and measurement technique.

Measurements and reference values

Measurement	Usual value	Note
Pleural effusion — maximum interpleural separation	measure mm	Largest distance between parietal and visceral pleura in the largest free pocket; basis of the Balik formula in supine patients.no measurable fluid: <10 mmestimable, context-dependent: 10–30 mmlarge or symptomatic: >30 mm + clínica
Pleural effusion — craniocaudal height	measure cm	In sitting or upright patients, measure the vertical fluid extent along the lateral/dorsolateral chest wall.not measurable: 0 cmsmall to moderate: <10 cmlarge, correlate symptoms: ≥10 cm
Lung base–diaphragm distance	measure cm	Subpulmonary distance used in Goecke 2 and Hassan formulas; improves the estimate when added to lateral height.
B-lines	≥ 3 per space or field	Diffuse bilateral pattern favors interstitial edema; focal or asymmetric pattern favors pneumonia, contusion, atelectasis or fibrosis.few/isolated: 0–2interstitial syndrome: ≥3diffuse pattern with distress: clinical urgency
Nodular pleural or diaphragmatic thickening	> 10 mm	When associated with pleural/diaphragmatic nodules or complex effusion, it is suspicious for malignancy; fluid should be analyzed when indicated.no thickening/nodule: absentsmooth/contextual thickening: <10 mmsuspicious: >10 mm ou nodular

Classifications and calculators

Interactive calculator — pleural effusion

Method	How to measure	Formula / use
Balik — supine	Maximum pleural separation in millimeters, in the largest free pocket.	Estimated volume = 20 × separation in millimeters. Useful at bedside; meaningful average error, does not replace measured drainage.
Eibenberger — supine	Separation between lung and posterior chest wall in millimeters.	Estimated volume = 47.6 × separation − 837. May become negative for small volumes; use as comparison.
Goecke 1 — sitting	Craniocaudal effusion height in centimeters.	Estimated volume = height × 90. Simple, but less complete than adding the subpulmonary distance.
Goecke 2 / Hassan — sitting	Lateral height + distance between lung base and diaphragm, in centimeters.	Estimated volume = (height + distance) × 70. Good correlation in drainage studies, still an estimate.
Do not use formula alone	Septations, internal echoes, pleural nodules, trauma, fever or marked dyspnea.	Color should be driven by complexity and clinical context; large volume does not define etiology.

Document side, patient position, window used, measurement used by the formula, and whether the fluid is free or loculated.

Source: Balik 2006 / Ibitoye 2018 / Hassan 2017 / EFSUMB / ERS

Pleural effusion — ultrasound appearance and meaning

Appearance	Practical interpretation	Color
No measurable pleural fluid	Normal for the question “is there effusion?”; still assess sliding, lines and consolidations according to symptoms.	Green: consensus normal for effusion.
Anechoic, free, mobile	May be transudate or exudate; ultrasound does not establish etiology without clinical/laboratory context.	Yellow: abnormal but not necessarily complicated.
Complex non-septated	Echoes/debris may occur in exudate, older hemothorax, inflammation or malignancy; correlate.	Yellow: contextual zone.
Septated, loculated or thick debris	Suggests complicated effusion, organized empyema or hemothorax; drainage may be difficult and diagnostic aspiration is often relevant.	Red when infection, trauma, marked loculation or clinical worsening is present.
Pleural/diaphragmatic nodules or nodular thickening >10 mm	Suspicious for malignancy, especially with recurrent or unilateral effusion.	Red: consensus suspicious abnormality.

Source: EFSUMB chest ultrasound / ERS statement / BTS pleural disease

Lung signs — teaching interpretation

Sign	How to recognize	Interpretation
Lung sliding present	Pleural line shimmers/moves with breathing.	Excludes pneumothorax at that scanned point.
A-lines with sliding	Repeated horizontal artifacts below the pleural line.	Aerated lung at that point; may be normal or obstructive depending on clinical context.
Three or more B-lines	Vertical artifacts arising from pleura, erasing A-lines and reaching the bottom of the screen.	Interstitial syndrome: edema if diffuse bilateral; pneumonia, contusion or fibrosis if focal/asymmetric.
Absent sliding + lung point	Transition between no-sliding and sliding areas.	Highly specific for pneumothorax in the correct context.
Subpleural consolidation with dynamic air bronchogram	Tissue-like area with moving hyperechoic dots/lines.	Favors pneumonia; distinguish from atelectasis by air movement and context.

Source: BLUE protocol / ERS thoracic ultrasound / EFSUMB

Technique and thorax report checklist

Item	What to report
Scanned windows	Anterior, lateral and posterior when possible; at bedside, describe recumbent-position limitations.
Pleural effusion	Side, estimated volume, formula used, patient position, free or loculated, anechoic/complex appearance.
Interstitium	Distribution of B-lines: focal, multifocal or diffuse; symmetry and relationship with pleural line.
Immediate alerts	Probable pneumothorax, infected complex effusion, suspected hemothorax, large effusion with distress or suspicious malignant signs.

Source: BTS pleural procedures 2023 / ERS / EFSUMB

Lung signs — interpretation (BLUE)

Sign	Interpretation
Lung sliding present	Excludes pneumothorax at that point
A-lines (horizontal)	Normally aerated lung (or pneumothorax if no sliding)
≥ 3 B-lines per field	Interstitial syndrome (edema, pneumonia, fibrosis)
No sliding + lung point	Pneumothorax (lung point is specific)
Anechoic collection above diaphragm	Pleural effusion (curtain/quad/sinusoid signs)

Source: Lichtenstein BLUE / Radiopaedia

Polycystic ovary (PCOS)

Measurements and reference values

Measurement	Usual value	Note
Follicle number per ovary (FNPO)	≥ 20 follicles 2–9 mm	PCOS US criterion (2018 update; previously ≥ 12)
Ovarian volume	≥ 10 mL	alternative criterion (no cyst/corpus luteum)

Classifications and calculators

Rotterdam — PCOS diagnosis (2 of 3)

Criterion	Definition
Oligo/anovulation	clinical
Hyperandrogenism	clinical or biochemical
Polycystic ovaries on US	FNPO ≥ 20 OR volume ≥ 10 mL

Needs 2 of 3 + exclusion of other causes. Do not apply the US criterion within < 8 years post-menarche.

Source: Intl Evidence-based Guideline (ESHRE/ASRM)

Renal arteries (native Doppler)

Renal artery stenosis thresholds vary across laboratories and guidelines. For international safety: clearly normal values are green; peak velocities from 180 to 199 cm/s, renal-to-aortic ratio close to 3.5, or isolated indirect findings are yellow; combined high velocity, renal-to-aortic ratio of 3.5 or higher, post-stenotic turbulence, or tardus-parvus waveform are red. Doppler findings should be interpreted with clinical context, renal function, kidney asymmetry, and acoustic window quality.

Measurements and reference values

Measurement	Usual value	Note
Common clinical indications	Resistant or abrupt-onset hypertension; progressive or unexpected renal function decline; renal function decline after angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy; abdominal bruit; kidney size difference greater than 2 cm; follow-up of known stenosis, angioplasty, or stent; suspected renal infarction, aortic dissection, aneurysm, pseudoaneurysm, arteriovenous fistula, or renal venous disease.	When renovascular hypertension is suspected, duplex Doppler is a widely accepted initial option when the acoustic window is adequate.
Minimum technical protocol	Measure the longest length of each kidney; assess the aorta at the renal artery level; map the main renal arteries from origin to hilum, including proximal, mid, and distal segments; look for accessory arteries when possible; record intrarenal waveforms in upper, mid, and lower poles; apply Doppler angle correction and keep the angle at 60 degrees or less.	If a segment is not visualized, the report should state that clearly rather than assuming normality.
Main renal artery peak systolic velocity	< 180 cm/s	Usually normal when isolated and waveform shape is preserved. Values from 180 to 199 cm/s are borderline in many protocols; 200 cm/s or higher increases suspicion for hemodynamically relevant stenosis, especially with an elevated renal-to-aortic ratio.
Renal-to-aortic ratio	< 3.5	Calculated as the highest renal artery peak systolic velocity divided by the aortic peak systolic velocity at the renal artery level. A ratio of 3.5 or higher is a strong criterion for significant stenosis when the aortic velocity is reliable.
Intrarenal acceleration time	<= 70 ms	Time greater than 70 ms, especially with a tardus-parvus waveform, suggests proximal stenosis. In isolation it may be borderline and should be compared with direct criteria.
Intrarenal acceleration index	>= 300 cm/s²	Values below 300 cm/s² support a tardus-parvus pattern, but they are most useful when combined with prolonged acceleration time and direct criteria.
Intrarenal resistive index	Usually < 0.70	Values from 0.70 to 0.79 suggest increased parenchymal resistance or relevant clinical context. A value of 0.80 or higher is abnormal and often reflects chronic parenchymal disease or worse prognosis, but it does not confirm stenosis by itself.
Kidney length and asymmetry	Typical adult: 9 to 12 cm; difference > 2 cm is relevant	A small kidney, asymmetry greater than 2 cm, or cortical loss increases suspicion for chronic disease, renal ischemia, or sequelae of longstanding stenosis.

Classifications and calculators

Teaching calculator — renal artery Doppler

Direct criteria for renal artery stenosis

Indirect intrarenal criteria

Resistive index and renal parenchyma

Pitfalls and differential diagnosis

After renal angioplasty or stent

Report checklist

Renal transplant (Doppler)

International protocols converge on the complete technical examination, but there is no single universal threshold for transplant renal artery stenosis. Interpretation should combine post-transplant timing, focal velocity, graft artery/iliac artery ratio, aliasing, intrarenal tardus-parvus waveform, resistive index, renal function and comparison with prior studies.

Measurements and reference values

Measurement	Usual value	Note
Minimum technical protocol	Grayscale + color Doppler + spectral Doppler	Document graft size, parenchyma, collecting system, bladder/ureter when applicable, perigraft space, graft artery and vein, anastomoses, adjacent iliac artery/vein, and intrarenal waveforms in upper, mid and lower poles.
Peak systolic velocity in the graft artery	<200 / 200-249 / 250-299 / >=300 cm/s	An isolated value can be false positive, especially immediately after surgery or in a tortuous artery. Risk increases with focal acceleration plus aliasing, iliac ratio >=2.0 and intrarenal tardus-parvus waveform.usually normal: <200 cm/sborderline or context-dependent: 200-249 cm/ssuspicious if isolated: 250-299 cm/sstrong when combined with direct/indirect criteria: >=300 cm/s ou >=250 cm/s + aliasing/razão alta/tardus-parvus
Graft artery / iliac artery ratio	<1,8 / 1,8-1,99 / >=2,0	Helps reduce false positives from high output or elevated systemic velocities. Measure the iliac artery adjacent to the anastomosis and use the same technique on follow-up.no proportional criterion: <1,8gray zone: 1,8-1,99abnormal when focal acceleration is present: >=2,0
Intrarenal tardus-parvus waveform	Acceleration time >70 ms or acceleration index <300 cm/s²	This is an indirect criterion; it carries more weight when distal to a focal acceleration. It can also occur with proximal iliac stenosis, hypotension or suboptimal technique.preserved waveform: rapid systolic upstrokeisolated or technical: time >70 ms or index <300 without focal jetstrong indirect criterion: tardus-parvus + high velocity/ratio
Intrarenal resistive index	0,60-0,70 / 0,70-0,80 / >0,80	It does not by itself separate rejection, tubular injury, drug toxicity, obstruction, venous compression or systemic congestion. Trend and clinical context matter more than one isolated measurement.common in stable graft: 0,60-0,70borderline or nonspecific: 0,70-0,80elevated, correlate: >0,80concerning if persistent or with dysfunction: >=0,90, fluxo diastólico ausente/reverso
Graft renal vein	Venous flow present, no thrombus and no marked focal acceleration	Absent venous flow, thrombus, marked graft enlargement and reversed arterial diastolic flow are critical findings and should be communicated.normal: patent veinevaluate compression or technique: focal acceleration without thrombuscritical: no flow, thrombus or reversed arterial diastolic flow
Collecting system and perigraft collections	Describe grade, size, location and compressive effect	Mild dilatation may be transient; moderate/severe dilatation, complex collection or compressive collection changes management, especially with pain, fever, reduced urine output or rising creatinine.no relevant finding: no dilatation and no compressive collectionfollow/correlate: mild dilatation or small simple collectionrelevant abnormality: marked dilatation, complex or compressive collection

Classifications and calculators

Interactive calculator — renal transplant Doppler

Source: ACR-AIUM-SPR-SRU 2024 / Clinical Radiology 2003 / AJR 2017 / UT Southwestern 2020

Acquisition checklist

Step	What to record
Grayscale	Graft location, length, cortical thickness/echogenicity, corticomedullary differentiation, renal sinus, collecting system, ureter/stent when visible, bladder and residual urine if indicated.
Perigraft space	Look for hematoma, seroma, lymphocele, urinoma or abscess; measure, locate and describe complexity and compressive effect.
Arterial Doppler	Measure adjacent iliac artery, anastomosis, proximal, mid and hilar graft artery; look for multiple arteries, kinking, aliasing and turbulence.
Intrarenal Doppler	Record waveforms in upper, mid and lower poles, with resistive index, acceleration time and acceleration index when stenosis is the clinical question.
Venous Doppler	Confirm patent renal and iliac veins without thrombus; in hematuria or recent biopsy, look for arteriovenous fistula and pseudoaneurysm.

Source: ACR-AIUM-SPR-SRU 2024 / UT Southwestern 2020

Graft artery stenosis — color reading

Color	Practical criteria	How to report
Green	No relevant focal acceleration; velocity <200 cm/s; iliac ratio <1.8; no distal tardus-parvus.	No ultrasound criteria for hemodynamically significant stenosis on the current study.
Yellow	Velocity 200-249 cm/s, or isolated 250-299 cm/s in postoperative/surveillance context, or borderline ratio, especially with tortuosity or difficult angle.	Borderline/contextual finding; correlate with renal function, blood pressure and prior Doppler.
Red	Velocity >=300 cm/s, or >=250 cm/s associated with aliasing/turbulence, ratio >=2.0 and intrarenal tardus-parvus waveform.	Combination of findings suspicious for hemodynamically significant stenosis; communicate and consider confirmation according to local protocol.

Source: Clinical Radiology 2003 / AJR 2017 / UT Southwestern 2020

Resistive index — cautious interpretation

Range	Color	Comment
0,60-0,70	Green	Common range in stable grafts, but always compare with baseline and clinical context.
0,70-0,80	Yellow	Intermediate zone; may be normal in some patients and abnormal in others.
>0,80	Yellow	Elevated and nonspecific: rejection, tubular injury, toxicity, obstruction, venous compression, systemic congestion and cardiovascular factors may overlap.
>=0,90 ou diástole ausente/reversa	Red	Concerning when persistent or associated with dysfunction; reversed diastolic flow requires prompt communication.

Source: UT Southwestern 2020 / Radiopaedia / review literature

Complications requiring communication

Finding	Why it matters	Color
No arterial flow in the graft	May represent arterial thrombosis, technical complication or severe hypoperfusion.	Red
No venous flow or thrombus in renal vein	May cause acute graft congestion and rapid functional loss.	Red
Reversed arterial diastolic flow	May occur with venous thrombosis, severe rejection, edema/high pressure or significant compression.	Red
Complex, infected or compressive collection	May indicate hematoma, abscess, urinoma or lymphocele affecting ureter/vessels.	Red
Post-biopsy arteriovenous fistula or pseudoaneurysm	May cause hematuria, vascular steal, enlargement or need for embolization.	Yellow/Red

Source: ACR-AIUM-SPR-SRU 2024 / UT Southwestern 2020 / vascular complication reviews

Didactic impression template

Source: SonoAI synthesis from cited sources

Bowel / IBD (Crohn)

Measurements and reference values

Measurement	Usual value	Note
Bowel wall thickness	≤ 3 mm	> 3 mm suggests inflammation (sens. 89% / spec. 96%)

Classifications and calculators

Calculator — appendicitis (US + Alvarado)

Finding	Reading
Appendix <6 mm, compressible	Usually normal.
6–7 mm or not visualized	Borderline: weigh secondary signs; non-visualization does not exclude.
≥7 mm non-compressible + signs	Appendicitis likely (inflamed fat, hyperemia, appendicolith).
Periappendiceal collection/fluid	Suspected perforation/abscess.

Alvarado: migratory pain (1), anorexia (1), nausea (1), RLQ tenderness (2), rebound (1), fever (1), leukocytosis (2), left shift (1). ≥7 = high probability; 5–6 = observe; ≤4 = low.

Source: ACR appropriateness / Alvarado 1986 / SPR pediatric US

Activity signs (Crohn on US)

Sign	Finding
Wall	Thickness > 3 mm
Vascularity	Hypervascularity (Limberg ≥ 2)
Mesenteric fat	Proliferation/inflammation (creeping fat)
Complications	Lymph nodes, stricture, fistula, abscess, ascites

Source: Intestinal US in IBD (PMC)

Liver elastography / steatosis

Classifications and calculators

Calculator — liver stiffness (kPa) + Baveno VII

Range (kPa)	Baveno VII / reading
< 10	Compensated advanced chronic liver disease unlikely.
10–15	Gray zone — suggests advanced disease, confirm.
≥ 15	Compensated advanced chronic liver disease probable.
≥ 25	Clinically significant portal hypertension probable (CSPH).

Fibrosis cutoffs vary by etiology and technique (TE/pSWE/2D-SWE). The calculator adjusts by etiology; quality control (IQR/median ≤0.30) is mandatory.

Source: Baveno VII 2022 / EFSUMB-WFUMB elastography guidelines

Liver fibrosis — SWE (orientative)

Stage	Stiffness (kPa)
F0–F1	< ~7
≥ F2 (significant)	~ 7–8,5
≥ F3 (advanced)	~ 9,5–10,4
F4 (cirrhosis)	≥ ~11,3–13

Cutoffs vary by device, probe and etiology — use your scanner's table. Example values (2D-SWE).

Source: Egypt J Radiol / Radiology Key (2D-SWE)

Steatosis — CAP (FibroScan)

Grade	CAP (dB/m)
S1 (> S0)	≥ ~248
S2 (> S1)	≥ ~268
S3 (> S2)	≥ ~280

Adjust for NAFLD/diabetes (+10) and BMI. Cutoffs vary by study (222–294 dB/m).

Source: J Med Ultrason (CAP meta-análise)

Obstetric — calculator & tables

Measurements and reference values

Measurement	Usual value	Note
CRL → GA (Robinson-Fleming)	IG(dias) = 8,052·√(CCN·1,037) + 23,73	CRL in mm (5–84 mm)
CRL → GA (INTERGROWTH-21st)	IG(dias) = 59,3615 + 0,4614·CCN	valid 11+0–13+6 wk
Estimated fetal weight (Hadlock IV)	log10(PFE)=1,3596+0,0064·CC+0,0424·CA+0,174·CF+0,00061·DBP·CA−0,00386·CA·CF	measurements in cm; EFW in g
EFW — INTERGROWTH-21st (AC+HC)	log(PFE)=5,084820−54,06633·(CA/100)³−95,80076·(CA/100)³·ln(CA/100)+3,136370·(CC/100)	natural log; AC/HC in cm; 2nd world reference

Classifications and calculators

EFW by gestational age — Hadlock (g)

Wk	p10	p50	p90
20	286	330	380
21	345	398	458
22	412	476	548
23	489	565	650
24	576	665	765
25	673	778	894
26	780	902	1038
27	898	1039	1196
28	1026	1189	1368
29	1165	1350	1554
30	1313	1523	1753
31	1470	1707	1964
32	1635	1901	2187
33	1807	2103	2419
34	1985	2312	2659
35	2167	2527	2904
36	2352	2745	3153
37	2537	2966	3403
38	2723	3186	3652
39	2905	3403	3897
40	3084	3617	4135

SGA < p10 · AGA p10–p90 · LGA > p90. Use the calculator above for automatic classification. Second world reference: INTERGROWTH-21st (official table, Stirnemann 2017).

Source: Hadlock 1991 (percentis)