History of inflammatory bowel disease on treatment presents with disease flare and rectal pain. Evaluate for perianal disease. PELVIS:PROSTATE/SEMINAL VESICLES: No significant abnormality noted.BLADDER: No significant abnormality noted.LYMPH NODES: Multiple prominent mesorectal lymph nodes are likely reactive given the colonic inflammation.BOWEL, MESENTERY: The visualized rectosigmoid and rectum is featureless and has diffuse mild circumferential wall thickening and mucosal hyperenhancement compatible with acute inflammation. Intrinsic T1-weighted submucosal signal also reflects submucosal fat deposition related to chronic inflammation as well. The inflammation is most severe near the anterior anorectal region where there is a fistulous tract originating from approximately the 11:00 position of the anus (series 501/29). The tract extends inferiorly within the right intersphincteric space and communicates with a right ischioanal fossa fluid collection measuring 1.9 x 1.3 x 2.4 cm. Extensive adjacent subcutaneous inflammation and skin thickening. The inflammation extends superiorly superficial to the external sphincter without a discrete fluid-filled tract.Small volume of right lower quadrant ascites. Possible inflammation of additional bowel loops which are partially imaged.BONES, SOFT TISSUES: Diffuse low T1 weighted signal intensity of the bone marrow likely reflects anemia.OTHER: No significant abnormality noted.
1.Intersphincteric fistula with an abscess in the right ischioanal fossa near the right gluteal cleft measuring up to 2.4 cm.2.Severe active inflammation of the visualized rectosigmoid colon.