Structures ultrasound interpretation with measurement protocols and ACR guidelines. Use when reading ultrasound exams, documenting sonographic findings, or creating US reports.
Structures ultrasound interpretation with measurement protocols and ACR guidelines.
Ultrasound is the primary imaging modality for obstetric evaluation, thyroid assessment, testicular pathology, hepatobiliary disease, and vascular studies. Unlike CT or MRI, ultrasound is operator-dependent — the quality of the study depends heavily on the sonographer's technique. The interpreting radiologist must assess both the sonographic findings and study completeness. ACR Practice Parameters mandate that reports include specific measurement protocols per organ system, standardized terminology (e.g., TI-RADS for thyroid nodules), and explicit technical-adequacy statements. Failure to apply standardized classification systems or recommend appropriate follow-up is a documented source of diagnostic error and malpractice liability.
The real-time, dynamic nature of ultrasound means that subtle findings may only be captured in select images. Reports must distinguish between findings visualized on stored images versus findings noted during real-time scanning, and should explicitly document when a region was not adequately visualized due to body habitus, bowel gas, or patient cooperation.
Verify that required views per ACR practice parameters are included.
Document any views not obtained and the reason (e.g., "Pancreatic tail not visualized due to overlying bowel gas").
Score each nodule using the five TI-RADS categories:
| Feature | 0 Points | 1 Point | 2 Points | 3 Points |
|---|---|---|---|---|
| Composition | Cystic/spongiform | Mixed cystic-solid | Solid or almost solid | — |
| Echogenicity | Anechoic | Hyper/isoechoic | Hypoechoic | Very hypoechoic |
| Shape | Wider than tall | — | Taller than wide | — |
| Margin | Smooth | — | Irregular | Extra-thyroidal extension |
| Echogenic foci | None/large comet-tail | — | Macrocalcifications | Punctate echogenic foci |
| TI-RADS Level | Points | FNA Threshold | Follow-up Threshold |
|---|---|---|---|
| TR1 — Benign | 0 | No FNA | No follow-up |
| TR2 — Not Suspicious | 2 | No FNA | No follow-up |
| TR3 — Mildly Suspicious | 3 | ≥2.5 cm | ≥1.5 cm |
| TR4 — Moderately Suspicious | 4–6 | ≥1.5 cm | ≥1.0 cm |
| TR5 — Highly Suspicious | ≥7 | ≥1.0 cm | ≥0.5 cm |
| Study Type | Key Measurements | Normal Values |
|---|---|---|
| Carotid duplex | ICA PSV, EDV, ICA/CCA ratio | <125 cm/s PSV = <50% stenosis |
| Renal artery | PSV, RI, acceleration time | RI 0.55–0.70; AT <70 ms |
| Hepatic | Portal vein velocity and direction | 15–40 cm/s, hepatopetal |
| DVT lower extremity | Compressibility, augmentation, spectral waveform | Full compressibility, phasic flow |
| Testicular | Intratesticular flow symmetry | Symmetric arterial flow bilaterally |
Always report spectral waveform pattern (low vs. high resistance), velocity values, and any reversal of flow.
Always specify follow-up per relevant classification system or ACR Incidental Findings Committee.
| Finding | Recommendation |
|---|---|
| TI-RADS 3 nodule ≥1.5 cm | Follow-up US in 1, 3, 5 years |
| TI-RADS 4 nodule ≥1.5 cm | FNA recommended |
| Simple hepatic cyst | No follow-up |
| Complex ovarian cyst, premenopausal | Repeat US in 6–12 weeks |
| Gallbladder polyp >10 mm | Cholecystectomy referral |
| Gallbladder polyp 6–9 mm | US in 6 months, then annually |
| Abdominal aortic aneurysm 3.0–3.9 cm | Repeat US in 12 months |
| AAA 4.0–5.4 cm | Repeat US in 6 months |