To provide an overview on the evaluation of perianal fistulas and to describe the typical MRI findings of the various types of fistulas with their classification.

Perianal fistula is an inflammatory condition that affects the region around the anal canal. It is characterized by a connection between the anal canal and the skin of the perineum. Perianal fistulization is an uncommon process, with a prevalence of 0.01%, although it causes signifi­cant morbidity and often requires repeated surgical treatments due to its high tendency to recur. It predominantly affects young males, with a male-to-female ratio of 2:1. The most common presenting symptom is discharge (65% of cases), but local pain due to...

The major MRI indication in perianal fistula is preoperative classification. MRI allows a direct visualization of the fistolous tracts and abscesses, com­bined with high soft tissue resolution. MRI help to classify accurately fistolous tracts but also to identify the entire extention of the disease that otherwise would have been missed. The most appropriate MR protocol used for evaluation of perianal fistulas consists of: oblique axial T1 and T2-weighted FSE, oblique axial and coronal fat-sup­pressed T1 and T2-weighted FSE, oriented perpendicular or paral­lel to the long...

MRI plays a crucial role in preoperative evaluation of perianal fistula, providing accurate definition of the fistulous track, its extension, its re­lationship to pelvic structures, and identifi­cation of secondary fistulas or abscesses. MR imaging provides accurate information for appropriate surgical treatment, decreasing the incidence of recurrence and allowing side effects such as fecal incontinence to be avoided [5]. By using the St James’s University Hospital classification, an MR imaging–based grading system validated by surgical exploration and longterm clinical outcome, the radiologist can alert the referring...

Dr. Maria Roberta Vaccaro Notte, Dipartimento di Scienze Radiologiche, Di.Bi.Med., Università di Palermo, Via del Vespro 127, 90100, Palermo, Italia; Phone: +393276988282; Mail: [email protected]

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