27 year old male with history of Crohn's disease and perianal abscess. Please evaluate for perianal abscess, fistula, sinus tract to evaluate for discomfort in left buttock, perianal pain. PELVIS:PROSTATE/SEMINAL VESICLES: No significant abnormality noted.BLADDER: No significant abnormality noted.LYMPH NODES: The reference pelvic perirectal lymph node demonstrates interval decrease in size, measuring 6 mm, previously 9 mm in short axis diameter (series 3; image 19).BOWEL, MESENTERY: Again seen is a T2 hyperintense tract extending from the five o'clock position of the anus with extension towards the gluteal skin along the left gluteal crease (series 4 image 51), which measures approximately 2 mm in diameter, previously 4 mm. This tract is associated with restricted diffusion. Findings are compatible with the known history of perianal fistula, appearing less pronounced when compared to the prior study.The reference saccular fluid collection located within the rectal wall above the anal sphincter measures 1.0 x 0.7, previously 1.6 x 0.9 cm and is compatible with a small intramural fluid collection (series 4; image 38).BONES, SOFT TISSUES: No significant abnormality noted.OTHER: There is no focal fluid collection or abscess.
1.The reference perianal fistula extending from the 5 o'clock position of the anus is persistent but appears less pronounced when compared to the prior study.2.Stable to slight interval decrease in size of the reference small intramural rectal fluid collection located above the anal sphincter.