MRI of perianal fistulas in Crohn's disease.

MRI has a crucial role in the evaluation and detection of CD perianal fistulas because, thanks to its panoramic and multiplanar view, it gives excellent anatomic detail of the anal sphincters. Today MRI is the gold standard imaging technique for the evaluation of perianal fistulas, mainly because this technique shows higher concordance with surgical findings than does any other imaging evaluation. Surgical treatment is often required in the management of perianal fistula in patients with CD, which often have complex perineal findings.