Antibiotic-induced diarrhea: specificity of abdominal CT for the diagnosis of Clostridium difficile disease.

PURPOSE: To evaluate the specificity of abdominal computed tomography (CT) in the diagnosis of Clostridium difficile disease.

MATERIALS AND METHODS: The authors retrospectively reviewed CT scans of 64 patients with C difficile disease and 30 control subjects with diarrhea and negative findings for C difficile disease at stool tests.

RESULTS: Colon wall thickening (range, 4-22 mm; mean, 11.7 mm; median, 11 mm) was seen in 39 patients (61%) with C difficile disease. Other findings included focal colon wall thickening (n = 28) and pancolonic thickening (n = 11). Two patients had only right-sided and transverse colon involvement. CT-specific diagnostic features of C difficile disease, such as nodular haustral thickening or the accordion pattern, were present in 17% of patients. No colonic abnormality was detected in 25 patients (39%). Seven of the 30 (23%) control subjects had colon wall thickening. Six of those seven subjects were subsequently determined to have ischemic colitis. The sensitivity of CT in the detection of colon abnormalities in patients with C difficile disease was 85%, and the specificity was 48%.

CONCLUSION: Specific CT features of C difficile disease are uncommon. A considerable number of patients (39%) with C difficile disease have normal abdominal CT scans.