BACKGROUND AND PURPOSE:

• Intestinal involvement may be seen in 5% to 12% of patients with endometriosis
• Patients may present with serious GI symptoms and signs (e.g., cyclical rectal bleeding)
• Transvaginal sonography is the first line imaging technique to detect intestinal endometriosis
• MRI and rectal endoscopic sonography (RES) are used as second line imaging modalities and also can determine depth of invasion
• Kim et al. (JMIG, 2017) compared accuracies of magnetic resonance imaging (MRI) and rectal endoscopic sonography (RES) in the prediction of the infiltration depth of colorectal endometriosis

METHODS:

• Retrospective cohort study
• Inclusion: Patients with symptomatic deep infiltrating endometriosis of the rectum who had colorectal resection
• All patients underwent abdominopelvic MRI and RES
• Performance characteristics and intermethod agreement were calculated

RESULTS:

• 40 patients were included in this study with a median age of 33 years
• MRI detection of muscularis layer invasion: PPV (100%)
• MRI detection of submucosal/mucosal layer involvement: Sensitivity (47%), specificity (81%), PPV(69%), NPV (63%)
• RES detection of muscularis infiltration: PPV (93%)
• RES detection of submucosal/mucosal layer involvement: Sensitivity (79%), specificity (48%), PPV (58%), NPV (71%)

CONCLUSION:

• Compared to RES, MRI is valuable in detecting rectal endometriosis but less accurate in detecting submucosal/mucosal involvement
• MRI PPV is higher for both muscularis and submucosal/mucosal infiltration
• However, RES has a better NPV for the detection of submucosal/mucosal infiltration
• When bowel involvement is detected by MRI, RES is not needed to confirm this finding
• If bowel infiltration is not detected by MRI, RES is necessary to rule out this finding (especially if a patient is symptomatic)

Learn More – Primary Sources:

Magnetic Resonance Imaging Compared with Rectal Endoscopic Sonography for the Prediction of Infiltration Depth in Colorectal Endometriosis

Related ObG Topics:

Evaluation and Treatment of Endometriosis

Does the Oral GnRH Antagonist Elagolix Improve Endometriosis-Associated Pain?

Laparoscopic Excision vs. Ablation for Treating Endometriosis-Associated Pain