Acute Sigmoid Diverticulitis

Axial CT image demonstrates left colonic wall thickening, pericolonic fat stranding, fascial thickening (arrowheads) and an inflamed diverticulum (arrow).

Facts: Acute Diverticulitis

• Diverticular disease found in 5-10% of people over the age of 45 years, and 80% by the age of 80
• Diverticulitis is the most common complication of diverticular disease. It is found in 10-25% of people with diverticular disease at some point.
• Most common site of diverticulitis = rectosigmoid colon
• Diagnosis made on a basis of clinical history (pain, fever, diarrhea), examination (abdominal tenderness, palpable mass), lab (elevated inflammatory markers, leucocytosis) and imaging.

Imaging

• CT is considered the best imaging method for diagnosing diverticulitis and characterizing its complications
• CT findings: diverticula, inflamed diverticula, pericolic fat stranding, colonic wall thickening, phlegmon, abscess, extraluminal air
• Differentiating acute diverticulitis from malignancy can be a problem since many findings overlap. Suspicion for malignancy is high if there are pericolonic lymph nodes and the involved segment is short and eccentric.

Reference:

Buckley O, Geoghegan T, O'Riordain DS, et al. Computed tomography in the imaging of colonic diverticulitis. Clin Radiol 2004; 59:977-983.