Are diverticula visible on ultrasound (USG)?

Visibility of Diverticula on Ultrasound (USG)

Yes, diverticula can be visualized on ultrasound, but with significant limitations compared to CT scan, which remains the gold standard imaging modality for diverticular disease.

Ultrasound Capabilities for Diverticula Detection

Ultrasound can detect diverticula with the following characteristics:

• Echogenic outpouchings from the colonic wall 1
• Visualization of inflamed diverticula in thickened areas of the colon 2
• Hyperechoic halos around diverticula indicating peridiverticulitis 3

Diagnostic Performance for Diverticulitis

• Sensitivity: 83-94% (higher with point-of-care ultrasound) 4
• Specificity: 88-90% 4, 1
• Positive predictive value: 96.2% 3
• Negative predictive value: 98.5% 3

Limitations of Ultrasound for Diverticula

Despite reasonable sensitivity for uncomplicated diverticulitis, ultrasound has significant limitations:

1. Poor detection of complications:

   • Only 21% accuracy for complicated diverticulitis 5
   • Low sensitivity (58.3%) for detecting complicated diverticulitis 4
   • Misses 79% of complicated cases 5

2. Technical challenges:

   • Operator-dependent with high variability in results 1
   • Limited effectiveness in obese patients 2
   • Uncomfortable for patients with acute abdominal pain 1
   • Less reliable for distal sigmoid diverticulitis 2

3. Diagnostic accuracy compared to CT:

   • CT remains superior with 92-99% sensitivity and 97-100% specificity 1, 2
   • CT better identifies alternative diagnoses and complications 1

Appropriate Clinical Use of Ultrasound for Diverticula

Ultrasound may be appropriate in specific scenarios:

• As first-line imaging in pregnant patients (along with MRI) 1
• When CT with IV contrast is contraindicated (severe kidney disease or contrast allergy) 1
• As initial screening in a sequential diagnostic strategy, followed by CT for negative or inconclusive findings 6
• For point-of-care assessment by emergency physicians (POCUS) with 94.1% sensitivity 4

Ultrasound Findings in Diverticular Disease

When performing ultrasound for suspected diverticulitis, look for:

• Colonic wall thickening >5mm 2, 3
• Target-like appearance in transverse view 3
• Local tenderness on gradual compression 3
• Hyperechoic pericolic tissue (noncompressible) 2
• Echogenic diverticula (visible in 86% of diverticulitis cases) 3

Conclusion

While ultrasound can visualize diverticula with reasonable accuracy for uncomplicated diverticulitis, CT remains the preferred imaging modality due to its superior ability to detect complications and alternative diagnoses. Ultrasound should be considered primarily when CT is contraindicated or as part of a sequential imaging approach.