Pelvic / transvaginal — Reference values

Pelvic / transvaginal — Reference values: Prepubertal uterus — length and thickness, Pubertal uterus — configuration, Ovary — volume in pubertal follow-up.

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 8Source: StatPearls 2025 / Radiologia Brasileira / Frontiers Endocrinol 2021
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 2:1–3:1Source: StatPearls 2025 / Radiologia Brasileira / Pediatric Radiology 2024
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 cm³Source: StatPearls 2025 / Radiologia Brasileira / Pediatric Radiology 2024
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 mmSource: Pediatric Radiology 2024 / StatPearls 2025
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 diastoleSource: Radiologia Brasileira / Pediatric Radiology 2024
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 deviceSource: AIUM / ACR-ACOG-AIUM-SPR-SRU female pelvis parameter
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 necrosisSource: AIUM / StatPearls / gynecologic ultrasound reviews
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 bleedingSource: AIUM / StatPearls
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 factorsSource: ACOG 2018/2026 / AIUM
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 massSource: AIUM / StatPearls / SRU adnexal guidance
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 openSource: AIUM / Connolly-Fox JUM 2021 / JSIM 2024 / Exxcellence 2025
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 morphologySource: AIUM / FIGO 2018 / MUSA / Merck PALM-COEIN

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

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