MRI of anal canal: common anal and perianal disorders beyond fistulas: Part 2.

A broad spectrum of disease, from benign processes to life-threatening pathologies, can cause anal pain. MR imaging (MRI) has become increasingly widely used method over the past two decades for the evaluation of individuals with anorectal symptoms. Although imaging is rarely necessary to determine the etiology of the majority of cases, MRI is particularly useful as a noninvasive method of excluding severe neoplastic conditions. In this article, MRI findings of a number of pathologies such as anal and perianal neoplasms, hemorrhoidal disease, arteriovenous malformation of the perianal region, and anal sphincter lesions (defects, scarring, atrophy) which may lead to fecal incontinence are presented.