Toxic megacolon in patients with severe acute colitis: computed tomographic features
Related Experiment Video
Updated: May 28, 2026

Fluorescence-mediated Tomography for the Detection and Quantification of Macrophage-related Murine Intestinal Inflammation
Published on: December 15, 2017
Véronique Moulin1, Perrine Dellon, Olivia Laurent
1Department of Radiology, Besançon University Hospital, 3 bvd Flelming, F-25030 Besançon, France.
Objective:
The objective of the study was to evaluate computed tomography (CT) in the differential diagnosis of patients with toxic megacolon (TM) complicating severe acute colitis (SAC) and patients with SAC but no TM.
Materials And Methods:
We identified 16 patients who presented clinically complicated SAC and CT examination before surgery. The CT scans of these patients were retrospectively evaluated in consensus by two abdominal radiologists blinded to the clinical and pathological results for CT findings of SAC, i.e., diffuse colonic wall thickening, submucosal edema, pericolonic fat stranding and ascites, and CT findings of TM reported in the literature, i.e., segmental colonic wall thinning, air-filled colonic distension over 6 cm with abnormal haustral pattern, nodular pseudopolyps and associated small bowel distension. Fisher's Exact Test was used for all statistical analyses.
Results:
Segmental colonic wall thinning with abnormal haustral pattern was noted in TM only (P=.001). As compared to patients with SAC but no TM as a complication, patients with TM showed statistically more frequent air-filled colonic distension over 6 cm (P=.001) and nodular pseudopolyps (P=.001). Diffuse colonic wall thickening (P=.036) and submucosal edema (P=.036) were more present in cases of uncomplicated SAC. Pericolonic fat stranding (P=.12), ascites (P=.6), and small bowel and gastric distension (P=1) were not distinctive criteria.
Conclusion:
Computed tomography is useful in distinguishing patients with TM from patients with SAC but no TM as a complication. The association of air-filled colonic distension >6 cm, abnormal haustral pattern and segmental colonic parietal thinning seems pathognomonic of TM and should lead to rapid surgery.
More Related Videos
Related Concept Videos
Inflammatory Bowel Disease I: Ulcerative Colitis
Inflammatory bowel disease, or IBD, encompasses a group of disorders characterized by chronic inflammation or ulceration of the gastrointestinal tract.
Risk Factors
The exact cause of IBD remains unclear, although it is believed to be due to a mix of genetic, environmental, microbial, and immune factors. Genetic factors are significant in determining susceptibility to IBD, with family history being a critical risk factor. Individuals with a first-degree relative who has IBD are at...
Imaging Studies III: Gastrointestinal Motility Studies and Virtual Colonoscopy
Radionuclide Testing
Radionuclide testing is a sophisticated medical technique for assessing gastrointestinal motility. It focuses on gastric emptying and colonic transit time. Radioactive markers track the movement of food through the digestive system, providing insights into gastrointestinal disorders.
In gastric emptying studies, a meal's liquid and solid...
Inflammatory Bowel Disease II: Ulcerative Colitis
Computed Tomography
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
Diverticular Disease of the Colon
Inflammatory Bowel Disease II: Crohn's Disease
Inflammatory bowel disease, commonly known as IBD, refers to a collection of disorders that lead to persistent inflammation of the gastrointestinal tract. The two types of IBD are ulcerative colitis, which impacts the colon, and Crohn's disease, which can involve any part of the gastrointestinal segment.
Crohn's disease
Crohn's disease is a chronic, systemic inflammatory bowel disease (IBD) that predominantly affects the gastrointestinal tract. It is marked by transmural...

