reporting-ultrasound-studies

# Reporting Ultrasound Studies

Structures ultrasound interpretation with measurement protocols and ACR guidelines.

## Why This Skill Exists

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.

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## Checkpoint A: Pre-Draft Intake (Mandatory)

1. **What type of ultrasound study is being interpreted?** (Default: Abdominal — specify: thyroid, pelvic, obstetric, vascular, renal, testicular, breast, MSK)
2. **What is the clinical indication?** (Default: Replace with actual indication from requisition)
3. **Are prior ultrasound studies available?** (Default: No priors)
4. **Were Doppler images obtained?** (Default: Yes, color and spectral Doppler included)
5. **Is this a screening or diagnostic study?** (Default: Diagnostic)
6. **Are there known lesions requiring follow-up measurement?** (Default: No)
7. **Was the study limited by patient factors (body habitus, bowel gas, non-fasting)?** (Default: No limitations)

### Documents to Request

- All static ultrasound images with annotations
- Cine clips (when available in PACS)
- Doppler waveform images with velocity measurements
- Sonographer worksheets with measurements
- Prior ultrasound reports and images for comparison
- Relevant lab values (hCG for OB, AFP/liver function for hepatic, TSH for thyroid)
- Requisition with clinical indication

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## Step 1: Technical Assessment and Study Completeness

Verify that required views per ACR practice parameters are included.

### Abdominal Ultrasound — Required Views
- Liver: right lobe (sagittal and transverse), left lobe, dome
- Gallbladder: long axis and transverse; wall thickness; CBD measurement
- Pancreas: head, body, tail (or note if obscured by gas)
- Kidneys: bilateral long axis with measurement; cortical thickness
- Spleen: long axis with measurement
- Aorta: proximal, mid, distal with AP diameter

### Thyroid Ultrasound — Required Views
- Each lobe: transverse and longitudinal with three-dimension measurements
- Isthmus: AP measurement
- Nodules: three dimensions, echogenicity, composition, margins, calcifications
- Regional lymph nodes: levels III, IV, VI

### Pelvic Ultrasound — Required Views
- Uterus: sagittal and transverse with dimensions; endometrial thickness
- Ovaries: bilateral with dimensions and volume calculation
- Adnexae: cul-de-sac for free fluid
- Transvaginal images when transabdominal is limited

Document any views not obtained and the reason (e.g., "Pancreatic tail not visualized due to overlying bowel gas").

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## Step 2: Organ-Specific Interpretation

### Thyroid — ACR TI-RADS Classification (2017)

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 |

### Hepatobiliary
- Liver echogenicity: normal, increased (fatty infiltration), coarsened (cirrhosis)
- Gallbladder wall: <3 mm normal; document stones, polyps, sludge
- CBD: <7 mm (or <10 mm post-cholecystectomy); measure at porta hepatis
- Portal vein: diameter, flow direction, velocity

### Renal
- Kidney length: 9–12 cm adult normal
- Cortical thickness: >1 cm normal
- Hydronephrosis grading: mild, moderate, severe (SFU system for pediatric)
- Renal masses: Bosniak classification applicable; document vascularity on Doppler

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## Step 3: Doppler Evaluation

| 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.

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## Step 4: Report Structure

### Header
- Patient demographics, study date, accession
- Examination type (e.g., "Complete abdominal ultrasound with Doppler")
- Clinical indication

### Comparison
- Prior ultrasound studies with dates; note modality differences (e.g., prior CT comparison)

### Technique
- Transducer type and frequency (if available)
- Scanning approach (transabdominal, transvaginal, both)
- Fasting status for hepatobiliary studies
- Technical limitations

### Findings
- Organ-by-organ in standard order
- Each finding: location → sonographic characteristics → dimensions → Doppler findings → change from prior

### Impression
- Numbered, clinically significant findings first
- Classification assignments (TI-RADS, Bosniak, etc.)
- Specific follow-up recommendations with timing and modality

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## Step 5: Follow-Up Recommendations

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 |

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## Checkpoint B: Post-Draft Alignment (Mandatory)

1. Are all required views documented or limitations noted?
2. Are classification systems (TI-RADS, Bosniak) correctly applied with all scoring features?
3. Do Doppler measurements include actual velocity values?
4. Are follow-up recommendations specific with timing and modality?
5. Is the impression addressing the clinical question directly?

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## Quality Audit

- [ ] Study completeness is assessed (all required views per ACR)
- [ ] Technical limitations are explicitly documented
- [ ] Each visualized organ includes dimensions where applicable
- [ ] TI-RADS scoring shows individual feature scores and total points
- [ ] Doppler evaluations include numeric velocity values (not just "normal")
- [ ] Gallbladder wall thickness and CBD diameter are measured
- [ ] Renal length and cortical thickness are documented bilaterally
- [ ] Liver echogenicity is characterized relative to renal cortex
- [ ] Classification systems are applied with management recommendations
- [ ] Prior comparisons referenced with specific dates
- [ ] Impression items are numbered and clinically prioritized
- [ ] Non-visualized structures are documented with reason
- [ ] Fasting status noted for hepatobiliary exams
- [ ] Laterality is explicit for all paired organs

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## Guidelines

1. Always document study completeness — ultrasound is operator-dependent and incomplete studies require explicit notation.
2. Apply ACR TI-RADS with itemized feature scores; do not assign a TI-RADS level without documenting each criterion.
3. Report Doppler values numerically — qualitative descriptors like "normal flow" are insufficient.
4. Measure the CBD at the porta hepatis consistently; document whether the patient was fasting.
5. For obstetric ultrasound, follow AIUM Practice Parameters for gestational age assessment, anatomy survey completeness, and biometric measurements.
6. When body habitus limits evaluation, recommend alternative imaging (CT or MRI) rather than simply noting the limitation.
7. Classify ovarian lesions using the O-RADS system when applicable, including risk stratification and management recommendation.