TOPLINE:

MRI using the ENZIAN and #ENZIAN scoring systems showed strong reliability in evaluating endometriosis in the ovarian (O) compartment and deep endometriosis in the vaginal/rectovaginal space (A), uterosacral ligaments (B), and rectosigmoid colon (C), with the best diagnostic accuracy in compartment O.

METHODOLOGY:

• Researchers conducted a meta-analysis, analysing 12 studies from January 2005 to January 2025 to compare MRI-based ENZIAN (five studies) and #ENZIAN (seven studies) classification scoring systems with surgery or laparoscopy (nine studies) for endometriosis.
• They assessed interobserver and intraobserver agreement per the ENZIAN and #ENZIAN systems across 11 compartments, including the peritoneum (P); tubo-ovarian compartment (T); compartments A, B, C, and O; and F locations — uterus (adenomyosis; FA), bladder (FB), intestine other than the rectum (FI), ureter (FU), and all other locations (FO).
• Diagnostic performance was evaluated by calculating the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) using surgery or laparoscopy as reference standards.
• The analysis included 2285 women aged 32-36 years with deep endometriosis, with chronic pelvic pain being the predominant symptom (n = 340).

TAKEAWAY:

• MRI achieved exceptional diagnostic accuracy for compartments O (sensitivity, 97.5%; specificity, 96.4%; PPV, 97.3%; NPV, 98.3%) and T (sensitivity, 94.1%; specificity, 89.1%; PPV, 76.3%; NPV, 96.8%).
• Moderate-to-high sensitivity (76.1%-83.4%) and strong specificity (87.8%-94.8%) were noted in compartments A, B, and C, with reasonably high PPV and NPV.
• Sensitivity was notably lower for three F locations: 64.6% for FA, 56.9% for FB, and 66.8% for FI.
• Inter and/or intraobserver agreement was excellent or substantial for compartments O, A, B, and C in most studies but was inconclusive for other compartments.

IN PRACTICE:

For endometriosis, “MRI showed high diagnostic values for compartments O (ovary), T (tuba-ovarian condition), A (vagina/rectovaginal space), B (utero-sacral ligaments), and C (rectum/sigmoid colon). Substantial to high agreement was observed in compartments O, A, B, and C. The diagnostic values of the P and F-compartments were either low, or could not be pooled, due to limited data, and therefore no conclusions could be drawn. Clear definitions and training might improve the role of MRI in the #ENZIAN score,” the authors wrote.

SOURCE:

The study was led by Yusra Mohamed, University of Amsterdam, Amsterdam, Netherlands. It was published online on November 29, 2025, in European Radiology.

LIMITATIONS:

The study was limited by potential bias from incomplete patient selection; reduced comparability as not all patients underwent a reference standard or did so within a 6-month interval; reduced confidence in diagnostic interpretations because radiologist experience was unspecified in approximately half of the studies; and the inability to extract definitions of F locations, hampering assessment of these compartments. The inclusion of studies solely from Europe limited generalisability.

DISCLOSURES:

The authors reported that this study did not receive any funding and declared having no conflicts of interest.