Imaging of the ischiorectal fossa.

A retrospective evaluation of 500 routine abdominal computed tomography scans revealed 21 cases of ischiorectal fossa disease in 16 patients. Pathologic processes included involvement by primary and secondary neoplasms, usually of gynecologic origin; rectal prolapse; and abscess. These abnormalities can be missed if the ischiorectal fossae are not included in routine abdominal scans. The anatomy of the ischiorectal fossae and their relationship to other pelvic organs are well demonstrated with high-resolution computed tomography scans as well as by magnetic resonance imaging.