Magnetic Resonance Colonography May Predict the Need for Bowel Resection in Colorectal Endometriosis

Purpose. To define if MRI findings in patients with deep pelvic endometriosis (DPE) may be predictive for the need of bowel resection. Material and Methods. A retrospective survey of 196 pelvic MRIs of women who received laparoscopic procedures for DPE was carried out. A pelvic MRI was performed in all patients: it consisted in T2w-TSE sequences in axial, sagittal, and coronal planes and T1w and THRIVE sequences in the axial plane; the exam was completed by MR-Colonography. Intestinal lesions were measured in short and long axis and the degree of stenosis was established. A multivariate logistic regression was used to identify the predictors of intestinal resection. Results. 57/196 patients received an intestinal resection. Multivariate logistic regression demonstrated a predictive value of short axis (Odds-Ratio = 2.29, ) and stenosis (Odds-Ratio = 1.20, ). ROC analysis showed that a cut-off value of 11 mm for the short axis and 30% for the stenosis may correctly classify, respectively, 96,94% (sensitivity 92,9% and specificity 98,56%) and 97,96% (sensitivity 94,74% and specificity 99,3%) of the cases. Conclusion. The presence of an endometriotic rectal nodule > 11 mm in short axis causing a stenosis > 30% in pelvic MRI reliably predicts the need of a rectal resection.