🔥 Acute Abdomen CT Imaging Differential Simulator

Measuring the Appendix — the Core Appendicitis Sign

A dilated, non-compressible appendix is the anchor CT finding.

• <6 mm: Normal diameter (placeholder reference range)
• >6-7 mm: Appendicitis cutoff (placeholder threshold)
• Present: Wall enhancement (placeholder finding)
• High: Sensitivity (placeholder estimate)

Caliper technique

Axial caliper measures outer wall to outer wall diameter.

Diameter alone rarely confirms diagnosis alone.

Periappendiceal Fat Stranding — Secondary Inflammatory Sign

Hazy increased density in RLQ fat signals surrounding inflammation.

• Reticular: Stranding pattern (placeholder descriptor)
• Proportional: Severity link (placeholder relation)
• RLQ: Location (placeholder region)
• Moderate: Specificity (placeholder estimate)

Fat density change

Inflammatory exudate raises fat attenuation locally.

Stranding severity tracks inflammation grade.

Sigmoid Wall Thickness — the Diverticulitis Anchor Sign

A thickened sigmoid colon wall points toward diverticulitis.

• <3 mm: Normal thickness (placeholder reference range)
• >4 mm: Diverticulitis cutoff (placeholder threshold)
• Sigmoid: Segment (placeholder location)
• High: Sensitivity (placeholder estimate)

Wall caliper

Measured perpendicular to bowel lumen wall.

Thickness scales with inflammatory severity here.

Diverticula — Outpouchings that Define the Disease

Small mucosal outpouchings along the sigmoid wall are pathognomonic.

• 3-10 mm: Typical size (placeholder range)
• Sigmoid-heavy: Distribution (placeholder pattern)
• Wall thickened: Inflamed variant (placeholder note)
• Perforation risk: Complication (placeholder note)

Outpouching appearance

Air or contrast filled sacs project from the wall.

Count and size rise with severity slider here.

RLQ vs LLQ — Location Settles the Differential

Quadrant location is the fastest differentiator on CT.

• RLQ: Appendicitis site (placeholder location)
• LLQ: Diverticulitis site (placeholder location)
• Uncommon: Overlap cases (placeholder note)
• Rare: Left-sided appendix (placeholder caveat)

Quadrant reasoning

Combine location with wall and fat signs together.

Slider blend shows both patterns coexisting visually.