Using imaging to determine depth of DIE

A recent study determined that magnetic resonance imaging (MRI) and rectal endoscopic sonography (RES) are of significant, but different value in determining the presence and depth of deep infiltrating endometriosis (DIE).

Forty patients with symptomatic DIE and infiltration of the rectum underwent both abdominopelvic MRI and RES to assess infiltration depth of colorectal endometriosis. In those patients where bowel invasion was confirmed by RES, segmental resection of the rectosigmoid was performed via laparoscopy. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive and negative likelihood ratios (LRs), and intermethod agreement were calculated for DIE of the rectosigmoid muscularis and submucosa/mucosa, confirmed by histopathological analysis.

For MRI detection of DIE of the muscularis, the sensitivity, specificity, PPV, NPV, and negative LR were 68%, 100%, 100%, 20%, and 0.32, respectively. For the MRI detection of DIE with submucosal/mucosal involvement, the sensitivity, specificity, PPV, NPV, and positive and negative LRs were 47%, 81%, 69%, 63%, 2.49 and 0.65, respectively. The PPV of RES detection of DIE of the muscularis was 93%. For the RES detection of DIE involving the submucosal/mucosal layers, the sensitivity, specificity, PPV, NPV, and positive and negative LRs were 79%, 48%, 58%, 71%, 1.51 and 0.44, respectively.

The authors concluded that MRI is useful for detecting DIE but less accurate than RES in detecting submucosal/mucosal involvement. But when MRI confirms bowel involvement then RES is not essential. However, when MRI is performed on symptomatic patients and bowel involvement cannot be detected, then RES is required to exclude bowel invasion. 

This study was published in a recent issue of the Journal of Minimally Invasive Gynecology.