Pseudomembranous colitis: can CT predict which patients will need surgical intervention?

Our purpose was to determine if patients with pseudomembranous colitis (PMC) requiring surgical intervention demonstrate radiographic features distinct from those of patients treated successfully with standard medical therapy.

The indications for a CT study and the imaging findings from 17 patients who required laparotomy with colon resection for PMC were retrospectively reviewed. The CT findings were compared with the findings from 17 control patients (matched by clinical presentation) with PMC who were treated medically and did not require surgical intervention.

None of the CT findings evaluated in this study were significantly different between the surgical and nonsurgical groups. The CT findings evaluated for the surgical and nonsurgical groups, respectively, were as follows: wall thickness of the colon: 17.8+/-6.6 and 16.9+/-3.9 mm; largest caliber of the colon: 6.8+/-1.6 and 6.1+/-1.2 cm; presence of the accordion sign: 52.9 and 70.6%; heterogeneous contrast enhancement pattern (target sign): 57.1 and 57.1%; pericolonic stranding: 82.4 and 88.2%; ascites: 70.6 and 58.8%; pleural effusion(s): 64.7 and 64.7%; and subcutaneous edema: 64.7 and 64.7%.

Although none of the CT findings evaluated in this study was significantly different between the surgical and nonsurgical groups, CT was often the initial diagnostic modality in both groups. It is important for radiologists to recognize the CT appearance of PMC and suggest the diagnosis. However, patient triage may not be based solely on the CT findings.