Detection and localization of deep endometriosis by means of MRI and correlation with the ENZIAN score

• The accuracy of MRI for deep endometriosis was 95%.
• The agreement between histopathological and MRI ENZIAN score was excellent (k = 0.824).
• The highest agreement was for adenomyosis (1.000) and lesions of utero-sacral ligaments (0.890).
• MRI ENZIAN score allows to obtain a correct preoperative staging of deep endometriosis.

PurposeTo determine the accuracy of ENZIAN score, as detected on MR imaging, compared to surgical-pathologic findings.Materials and methodsThis retrospective study was approved by the investigational review board and the requirement for informed patient consent was waived. 115 patients were included according to following criteria: tubo-ovarian and/or deep endometriosis suspected at physical examination and transvaginal ultrasound; availability of MR examination; histopathological results from laparoscopic or surgical treatment. Exclusion criteria: lack of available MR examination, and/or (b) lack of a definitive histopathological results.Histopathological findings from bioptic specimens obtained during laparoscopic or laparotomic treatment were considered as reference standard.For all detected lesions a score according to ENZIAN score (revised 2010) was assigned both for MRI and histopathological findings.By comparing MRI-ENZIAN score and histopathological-ENZIAN score the overall sensitivity, specificity, accuracy, positive and negative predictive values in relation to presence/absence of deep endometriosis in each patient were calculated. k-Cohen to evaluate the degree of concordance between MRI-ENZIAN score and histopathological-ENZIAN score was also measured. Moreover the sensitivity, specificity, accuracy, positive and negative predictive values for each specific localization provided by ENZIAN score were also calculated.ResultsAt histopathology, the diagnosis of deep endometriosis was confirmed in 82/115 (71.3%) patients.The sensitivity, specificity, accuracy, PPV and NPV of MRI were 94%, 97%, 95%, 99%, 86%, respectively. The highest accuracy was for adenomyosis (100%) and endometriosis of utero-sacral ligaments (USLs) (98%), slightly lower for vagina-rectovaginal septum an colo-rectal walls (96%), and the lowest for bladder endometriosis (92%).The concordance between histopathological and MRI ENZIAN score was excellent (k = 0.824); in particular it was 0.812 for lesions in vagina-rectovaginal space, 0.890 for lesions in USL, 0.822 for lesions in rectum–sigmoid colon, 1.000 for uterine adenomyosis, and 0.367 for lesions located in the bladder wall.ConclusionMRI correlates with the ENZIAN score and has an accuracy of 95% in the detection and localization of deep endometriosis, allowing to minimize false negative results (4%) in patients with deep endometriosis and to obtain a correct preoperative staging.