Toxic megacolon in patients with severe acute colitis: computed tomographic features

Area of Science:

• Radiology
• Gastroenterology
• Abdominal Imaging

Background:

• Severe acute colitis (SAC) can present with or without toxic megacolon (TM).
• Accurate differential diagnosis is crucial for appropriate patient management.
• Computed tomography (CT) is a key imaging modality in evaluating acute abdominal conditions.

Purpose of the Study:

• To evaluate the utility of CT in distinguishing TM complicating SAC from SAC without TM.
• To identify specific CT findings indicative of TM.

Main Methods:

• Retrospective analysis of CT scans from 16 patients with clinically complicated SAC.
• Radiologists assessed CT findings for SAC and TM criteria.
• Statistical analysis using Fisher's Exact Test.

Main Results:

• Segmental colonic wall thinning with abnormal haustral pattern was specific to TM (P=.001).
• TM cases showed significantly more air-filled colonic distension >6 cm and nodular pseudopolyps (P=.001).
• Diffuse colonic wall thickening and submucosal edema were more frequent in uncomplicated SAC (P=.036).

Conclusions:

• CT is valuable for differentiating TM from SAC.
• A combination of colonic distension >6 cm, abnormal haustral pattern, and segmental colonic wall thinning is pathognomonic for TM.
• These CT findings should prompt urgent surgical consultation.