MR imaging for preoperative characterization of pelvic adhesions: role in diagnosis and surgical planning

Pelvic adhesions are nonanatomic connections between organs and normal peritoneal surfaces that develop secondary to a maladaptive inflammatory response to tissue insults. Comprised of fibrous tissue, adhesions can result in the distortion of operative dissection planes, which can complicate the establishment of abdominal access in patients undergoing surgery, prolong the length of surgery, and increase the risk of injury to bowel and other structures if involved by extensive adhesive disease. This can adversely impact patient outcomes by increasing the risk of surgical complications including bleeding, infection, and prolonging postoperative length of stay. Literature on the characterization of adhesions with imaging is limited and a systematic framework for evaluating adhesive disease on cross-sectional imaging of the pelvis does not currently exist. In this review, we discuss the MR imaging features of pelvic adhesions, highlighting unique teaching cases in which surgical exploration was significantly complicated by the presence of adhesive disease. We will also review the correlation between MR imaging and intraoperative findings in these cases. A proposed standardized framework for the detection and characterization of adhesions on pelvic MRI will be reviewed with multiple imaging examples. Identification and characterization of pelvic adhesive disease on preoperative imaging provides radiologists with an opportunity to inform the referring clinician of their presence, potentially improving outcomes and the quality of patient care.