O-RADS US Assessment: Optimizing Technique and Image Interpretation

A practical radiology review of O-RADS US Assessment: Optimizing Technique and Image Interpretation, focused on imaging findings, differential diagnosis, reporting points, and high-yield teaching pearls.

Core Concept

• O-RADS US = risk stratification system for adnexal lesions
• US = first-line, MRI = problem-solving
• Operator-dependent → technique = EVERYTHING

O-RADS Risk Categories

0. Inadequate

1. Normal

2. Benign (<1%)

3. Low risk (1–<10%)

4. Intermediate (10–<50%)

5. High risk (≥50%)

SCAN OPTIMIZATION

• Gray-scale (3-step)

FOV

• ROI ≥ 2/3 screen
• Avoid too deep / too shallow
• Gain -->
• Too high → cyst looks solid
• Too low → solid looks cystic
• Focal Zone (FZ)
• Place at or just below lesion
• Multiple FZ → ↓ frame rate
• Doppler (3-step)
• Color box
• Tight around lesion
• Scale (PRF)
• Too high → miss flow
• Too low → aliasing/artifact
• Color gain
• Increase → until blooming → decrease
• Spectral Doppler
• Confirms real flow
• NOT part of O-RADS scoring

MEASUREMENT PEARLS

• Use largest dimension ANY plane (not standard axes!)
• For follow-up → use ALD (average linear dimension)
• Papillary projection = ≥3 mm height
• CINE CLIPS = MUST

Detect

• tiny papillary projections
• wall irregularities
• mobile debris vs solid
• Static images alone = dangerous

KEY MANEUVERS

↔ Sliding sign

• Moves separately → extraovarian
• Moves together → ovarian

Jiggle sign

• Mobile echoes → debris
• Fixed → possible solid

Bowel displacement

• Push bowel away → better visualization

COMMON PITFALLS

• Artifact traps
• Refractive artifact ≠ shadowing
• Shadowing → benign fibrous lesion clue
• Bowel mimicking dermoid
• Looks like echogenic lines/dots
• Peristalsis = bowel
• Fake septations
• Partial volume / follicles
• True septa = thicker + extend wall-to-wall
• Debris vs solid
• Cine → mobility = debris
• Exophytic fibroid vs adnexal mass

Look for

• 2 normal ovaries
• bridging vessels
• sliding vs uterus

PROBE SELECTION

• Use highest frequency possible
• TVUS > transabdominal (better resolution)
• TAUS useful for large masses

CLINICAL TAKE-HOME

• US is NOT a limitation → it’s a dynamic advantage
• Small setting tweaks = BIG diagnostic impact

Goal

• ↓ unnecessary surgery
• ↑ cancer detection accuracy

FINAL PEARLS

• Cine everything
• Measure correctly
• Optimize settings before scanning
• Use dynamic maneuvers
• Always question artifacts