Halligan S, Stoker J (2006) Imaging of fistula in ano. Radiology 239:18–33PubMedCrossRef

Koelbel G, Schmiedl U, Majer MC et al. (1989) Diagnosis of fistulae and sinus tracts in patients with Crohn disease: value of MR imaging. AJR 152:999–1003PubMed

Barker PG, Lunniss PJ, Armstrong P et al. (1994) Magnetic resonance imaging of fistula-in- ano: technique, interpretation and accuracy. Clinical Radiology 49:7–13PubMedCrossRef

Beets-Tan RG, Beets GL, van der Hoop AG et al. (2001) Preoperative MR imaging of anal fistulas: does it really help the surgeon? Radiology 218:75–84PubMed

Sandborn WJ, Fazio VW, Feagan BG, Hanauer SB. American Gastroenterological Association Clinical Practice Committee (2003) AGA technical review on perianal Crohn’s disease. Gastroenterology 125:1508–1530CrossRef