PurposeTo evaluate magnetic resonance (MR) imaging morphologic- and signal intensity abnormalities of deep infiltrating endometriosis (DIE) of the bowel wall and to assess its value in predicting depth and extent of bowel wall infiltration.Materials and methodsThis single-center study was performed in a tertiary referral center for endometriosis. All patients (n = 28) who underwent segmental bowel resection (2004–2010) were retrospectively studied. MR images were analyzed by two experienced readers independently (number of lesions, location, size, signal intensity, and depth of bowel wall infiltration) and this was correlated with histopathology.ResultsThe sensitivity, specificity, positive and negative predictive values, and accuracy for diagnosis of endometriosis infiltrating the muscular layer of the bowel were 100%, 75%, 96%, 100%, and 96%, respectively. The inter-rater agreement was 0.84. “Fan shaped” configurations with hypointensity on T2- and T1-weighted imaging were characteristic for thickening of indigenous smooth muscle and smooth muscle hyperplasia at histopathology, as a consequence of infiltration by endometriosis. Thickening of the (sub)mucosa corresponded to edema with or without infiltration of endometriosis.ConclusionMR imaging at 1.5 Tesla is useful to predict muscular infiltration of the bowel in endometriosis, whereas it is of limited value in diagnosis of (sub)mucosal infiltration.

ObjectiveAbdominal wall endometriosis (AWE) is defined as endometrial tissue that is superficial to the peritoneum. AWE is often difficult to diagnose, mimicking a broad spectrum of diseases. The aim of this study was to describe the appearance of AWE on magnetic resonance (MR) imaging.MethodsWe present ten patients with AWE (12 lesions) in which MR imaging was used for diagnosis. MR imaging included T2-weighted imaging and T1-weighted imaging with fat suppression. To assess the value of diffusion-weighted imaging (DWI) in endometriosis, four patients underwent additional DWI. The apparent diffusion coefficient (ADC) was calculated using b values of 50, 400, 800 and 1,200 s/mm2.ResultsIn most cases, the lesion was located ventral or dorsal to the aponeurosis of the rectus oblique muscle (n = 6) or in the rectus abdominis (n = 5). MR of AWE lesions showed isointense or slightly hyperintense signal compared with muscle on T2-weighted images and showed isointense or slightly hyperintense signal compared with muscle on T1-weighted images with foci of high signal intensity, indicative of haemorrhage. The mean ADC value of AWE was 0.93 × 10–3/mm2/s.ConclusionMR imaging seems to be useful in determining the location and depth of infiltration in surrounding tissue preoperatively.

Purpose: To assess the value of magnetic resonance (MR) diffusion-weighted imaging (DWI) in the evaluation of deep infiltrating endometriosis (DIE). Materials and Methods:In a prospective single-center study, DWI was added to the standard MRI protocol in 56 consecutive patients with known or suspected endometriosis. Endometriotic lesions as well as (functional) ovarian cysts were analyzed for location, size, and signal intensity on T1, T2, and DWI. Apparent diffusion coefficient (ADC) values were calculated using b-values of 50, 400, 800, and 1200 s/mm 2 . Statistical analysis included the Spearman correlation coefficient, Mann-Whitney U, and Kruskal-Wallis tests.Results: A total of 112 lesions (62 endometrial cysts and 48 DIE) were detected, 60 of which were large enough to analyze. Mean ADC values of endometrial cysts and functional ovarian cysts were 1.11 Â 10 Conclusion: Results of our study suggest that ADC values of DIE are consistently low, without significant difference between pelvic locations.

Purpose Endometriosis is a common disease, associated with persistent and severe symptoms including infertility and pain, however, pathogenesis remains poorly understood. It has been hypothesized that fragments of viable endometrial tissue shed at menstruation reach the peritoneal cavity and other distant sites by retrograde menstruation and dissemination into the lymphatic system. In this study, uterine lymphatic and blood micro-vessel populations were compared in women with and without endometriosis during the menstrual cycle. Methods Paraffin-embedded hysterectomy specimens from premenopausal women with histologically normal endometrium (37 control and 42 endometriosis) were obtained. Immunohistochemical staining was performed with antibodies for D2–40 (lymphatic endothelium), CD31 (pan-endothelial marker), and endoglin (activated endothelial cells in angiogenesis). Lymphatic (LVD) and blood (BVD) micro-vessel density were quantified with an automated cellular imaging system using color and morphometric properties to identify micro-vessels. Results Subtle but significant differences in uterine BVD and LVD were detected in endometriosis. LVD was significantly increased in basal layer endometrium of endometriosis patients during the proliferative phase (mean ± SD = 54.3 ± 20.1 vs. 41.4 ± 9.9, p = 0.025). Endoglin-positive BVD was increased in the subepithelial region of endometrium in endometriosis during the secretory phase (19.3 ± 16.6 vs. 6.4 ± 8.2, p = 0.038). Conclusions This report for the first time demonstrates that endometrial LVD is altered in women with endometriosis and supports changes in BVD in these women. These alterations are likely to contribute to pathogenesis of endometriosis, through lymphatic spread and increased angiogenic potential of shed endometrial fragments.