Magnetic resonance imaging evaluation of perianal fistula

Abstract

To clarify the role of MRI in diagnosis and classification of perianal fistula and to evaluate the additional clinical value of preoperative MR imaging and its benefit to surgeon. This prospective study contained 25 patients (21 males and 4 females; age range 10–60 years; mean age 34.8 years) selected from 40 patients referred to the Radiodiagnosis department with perianal sepsis, the study was conducted between October 2009 and September 2011, MRIs were performed and the results were ensured by surgical results, sensitivity, specificity and predictive values of MRIs were determined. 25 patients with perianal sepsis were included in this study, 3 cases grade 1 (simple linear intersphincteric fistula), 2 cases grade 2 (intersphincteric fistula with abscess or secondary track), 9 cases grade 3 (trans-sphincteric fistula), 9 cases grade 4 (trans-sphincteric fistula with abscess (5 cases), secondary track within the ischiorectal fossa (3 cases) and both (1 case)) and 2 cases grade 5 (supralevator and translevator disease one case for each). MRI is a useful procedure for successful management of peri-anal fistula by correct assessment of the extent of disease and relationship to sphincter complex. Also it helps in identification of secondary extensions, particularly horseshoe tracts and abscesses resulting in complete evaluation and highest possible diagnostic accuracy aiding successful surgical interventions, aiming to reduce complications and recurrences.