Is there a role for magnetic resonance imaging in diagnosing colovesical fistulas?

Colovesical fistula is a devastating complication, usually secondary to diverticulitis or colon cancer. Imaging plays a crucial role in delineating the underlying anatomy and identifying an etiologic factor. Barium enema, computed tomography, and cystoscopy have been the mainstays of investigation, but they have less than ideal sensitivity and specificity. This study assessed the role of magnetic resonance imaging (MRI) in the investigation of patients with probable colovesical fistulas.

A total of 22 patients with presentations suspicious for enterovesical fistulas who underwent evaluation with axial T(1)-weighted and axial, coronal, and sagittal T(2)-weighted 1.5T MRI (body-phased array) were identified. Of the 22 patients, 19 underwent laparotomy and repair.

MRI correctly identified the presence of a fistula and defined the underlying etiology in 18 of 19 patients. Colovesical fistula was correctly excluded in 1 of 19 patients. The remaining 3 patients were either unfit for surgery or refused.

The results of our study have shown that MRI is an accurate method of evaluating patients with suspicion of colovesical fistulas, identifying the anatomy of the tract, as well as the etiology. This is not only useful for diagnosis, but also for surgical planning.