Thyroid / cervical — Reference values: Right/left lobe — length, Right/left lobe — width, Right/left lobe — anteroposterior thickness, Total thyroid volume — female.
| Measurement | Usual value | Note |
|---|---|---|
| Right/left lobe — length | 4–6 cm | adult; measure each lobe separatelySource: PMC Thyroid ultrasound / Endotext |
| Right/left lobe — width | 1–2 cm | Source: PMC Thyroid ultrasound / Intedia |
| Right/left lobe — anteroposterior thickness | 1,3–1,8 cm | up to ~2.0 cm may be accepted by some referencesSource: PMC Thyroid ultrasound / ATA teaching material |
| Total thyroid volume — female | 10–15 mL | usual range; classic upper limit for goiter: >18 mLSource: PMC Thyroid ultrasound / EJE 2025 |
| Total thyroid volume — male | 12–18 mL | 25 mL is better treated as a classic upper limit, not as a normality targetSource: PMC Thyroid ultrasound / EJE 2025 |
| Volume calculation for each lobe | C × L × E × 0,479 | length, width and thickness in cm; add both lobesSource: WHO/ICCIDD ultrasound volume formula |
| Isthmus — thickness | ≤ 3–4 mm | ✓ applied automatically in the reportSource: Intedia / Endotext |
| Thyroid parenchyma — color Doppler | sparse to moderate and symmetric | Marked diffuse hypervascularity is abnormal and should be correlated with TSH, free T4 and antibodies.Source: Ralls AJR 1988 / QJM 2025 |
| 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/sSource: Frontiers Endocrinol 2024 meta-analysis / Arch Endocrinol Metab 2019 |
| 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)
| 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
| 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
| 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
| 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
| 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
| 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