Abdomen (total / upper) — Reference values

Abdomen (total / upper) — Reference values: Liver — craniocaudal length at the midclavicular line, Spleen — adult long axis, Common bile duct with gallbladder present.

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✓ applied automatically in the reportSource: Clinical Ultrasound in Hepatology / Radlines
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✓ applied automatically in the reportSource: EFSUMB spleen / StatPearls
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 benignoSource: EFSUMB hepatobiliary / Cleveland Clinic J Med 2022
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 mmSource: EFSUMB hepatobiliary / Cleveland Clinic J Med 2022
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 mmSource: EFSUMB hepatobiliary / Abdominal Radiology
Gallbladder — fasting wall thickness	≤ 3 mm	pseudothickening occurs when the gallbladder is contracted or not fastingnormal: ≤3 mmborderline/context: >3–4 mmthickened: >4 mm✓ applied automatically in the reportSource: EFSUMB hepatobiliary / StatPearls
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 mmSource: SRU 2022 Radiology / ESGAR-EAES-EFISDS-ESGE 2022
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✓ applied automatically in the reportSource: Polish Ultrasound Society / StatPearls
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 hepatofugalSource: Polish Ultrasound Society / liver Doppler reviews
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✓ applied automatically in the reportSource: EFSUMB pancreas / Pancreatic ultrasound update 2024
Pancreas — approximate thickness	cabeça ~2; corpo/cauda 1–2 cm	isolated size is not robust; prioritize duct, contour and focal lesionsSource: EFSUMB pancreas
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✓ applied automatically in the reportSource: USPSTF / ACC-AHA 2022 / SVS
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%Source: ASE chamber quantification / POCUS Academy
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 directionSource: ACR-AIUM-SPR-SRU abdomen parameter / StatPearls Liver Doppler
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-parvusSource: StatPearls Liver Doppler / AJR liver Doppler
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 collateralsSource: StatPearls Liver Doppler / liver Doppler reviews
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 focalSource: StatPearls Liver Doppler / institutional TIPS protocols

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

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