title: MR imaging evaluation of perianal fistulas: spectrum of imaging features.
abstract: Perianal fistulization is an inflammatory condition that affects the region around the anal canal, causing significant morbidity and often requiring repeated surgical treatments due to its high tendency to recur. To adopt the best surgical strategy and avoid recurrences, it is necessary to obtain precise radiologic information about the location of the fistulous track and the affected pelvic structures. Until recently, imaging techniques played a limited role in evaluation of perianal fistulas. However, magnetic resonance (MR) imaging now provides more precise information on the anatomy of the anal canal, the anal sphincter complex, and the relationships of the fistula to the pelvic floor structures and the plane of the levator ani muscle. MR imaging allows precise definition of the fistulous track and identification of secondary fistulas or abscesses. It provides accurate information for appropriate surgical treatment, decreasing the incidence of recurrence and allowing side effects such as fecal incontinence to be avoided. Radiologists should be familiar with the anatomic and pathologic findings of perianal fistulas and classify them using the St James's University Hospital MR imaging-based grading system.
authors.affiliation: Department of Radiology, Central Radiodiagnostic Unit, Hospital del Henares, 28822 Coslada, Spain. jaimedemiguel@telefonica.net
authors.forename: Jaime
authors.initials: J
authors.lastname: de Miguel Criado
authors.forename: Laura García
authors.initials: LG
authors.lastname: del Salto
authors.forename: Patricia Fraga
authors.initials: PF
authors.lastname: Rivas
authors.forename: Luis Felipe Aguilera
authors.initials: LF
authors.lastname: del Hoyo
authors.forename: Leticia Gutiérrez
authors.initials: LG
authors.lastname: Velasco
authors.forename: M Isabel Díez Pérez
authors.initials: MI
authors.lastname: de las Vacas
authors.forename: Ana G
authors.initials: AG
authors.lastname: Marco Sanz
authors.forename: Marcos Manzano
authors.initials: MM
authors.lastname: Paradela
authors.forename: Eduardo Fraile
authors.initials: EF
authors.lastname: Moreno
mesh_terms: D001003:Anal Canal / Q000473:pathology*; D001004:Anus Diseases / Q000473:pathology*; D006801:Humans; D007412:Intestinal Fistula / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D017773:Pelvic Floor / Q000473:pathology*