MAGNETIC-RESONANCE-IMAGING OF FISTULA-IN-ANO

PURPOSE: Successful management of anal fistulas depends upon accurate assessment of the primary tract and any secondary extensions. Preoperative imaging has, to date, been disappointing. METHODS: A prospective study of 35 patients with a clinical diagnosis of fistula-in-ano was performed comparing magnetic resonance imaging with the independently documented operative findings. Magnetic resonance imaging was also compared with anal endosonography in 20 patients. RESULTS: Magnetic resonance imaging is accurate and demonstrates pathology missed at surgery by experienced coloproctologists. Magnetic resonance imaging is superior to anal endosonography. CONCLUSIONS: Magnetic resonance imaging is advocated as the method of choice when imaging is required for anal fistulas.