Contents lists available at ScienceDirect European Journal of Radiology journal homepage: www.elsevier.com/locate/ejrad Research article Deep infiltrating endometriosis: Can magnetic resonance imaging anticipate the need for colorectal surgeon intervention? Ana Brusic a,2, *, Stephen Esler a , Leonid Churilov b , Prathima Chowdary c,1 , Matthew Sleeman c , Peter Maher c , Natalie Yang a a Austin Hospital, Radiology Department, Level 2 Lance Townsend Building, 145 Studley Rd, Heidelberg, Victoria, 3084, Australia b Florey Institute of Neuroscience & Mental Health, Statistics and Decision Analysis Academic Platform, 245 Burgundy St Heidelberg, Victoria, 3084, Australia c Mercy Hospital for Women, Endosurgical Unit, 163 Studley Rd, Heidelberg, Victoria, 3084, Australia ARTICLE INFO Keywords: Deep infiltrating endometriosis DIE MRI Bowel resection Resource allocation ABSTRACT Objective: To identify magnetic resonance imaging (MRI) features associated with colorectal surgical bowel resection for treatment of deep infiltrating endometriosis (DIE). Materials and methods: 122 preoperative pelvic MRIs in women with laparoscopically-proven DIE and sub- sequent surgery (2006–2015) were identified, and retrospective cohort analysis performed. MRIs were reviewed independently by two radiologists blinded to surgical/histopathological outcomes. Associations between MRI characteristics of middle/posterior compartment endometriosis and surgical outcomes were investigated to identify MRI features associated with colorectal surgical bowel resection. Results: MRI features associated with colorectal surgical intervention were: presence of an MRI bowel lesion (sensitivity 95.3%, specificity 63.3%, ROC-AUC 0.79); MRI bowel lesions ≥20 mm in length (sensitivity 91%, specificity 77%, ROC-AUC 0.84); MRI bowel lesions invading the muscularis or submucosa/mucosa layers (sensitivity 95.3%, specificity 63.3%, ROC-AUC 0.90). Conclusion: This study identifies MRI features that have potential diagnostic utility in identifying the need for colorectal surgical intervention in patients with DIE. 1. Introduction Endometriosis is a common disease in women of childbearing age [1] with significant morbidity including dysmenorrhea, dyspareunia, infertility, dyschezia and dysuria. Endometriosis is defined as the pre- sence of endometrial tissue outside the uterine cavity [2], with three distinct morphologies: superficial endometriosis, ovarian endometriosis (endometriomas) and deep infiltrating endometriosis (DIE). DIE re- presents endometriosis that infiltrates > 5 mm into the retro- peritoneum/pelvic organs and is associated with scarring and adhe- sions. Common sites are the pelvic peritoneum (pouch of Douglas [POD], torus uterinus [TU], uterosacral ligaments[USLs]), bowel and bladder [3]. Clinical history and examination are unreliable in the diagnosis of DIE [4], and laparoscopy with histological confirmation is the diag- nostic gold standard [5]. However, non-invasive preoperative in- vestigations are increasingly utilized to assess disease extent, aiding surgical planning, assisting consent and facilitating resource and per- sonnel allocation. Both ultrasound and magnetic resonance imaging (MRI) are increasingly used in this capacity [3,6,7], with MRI showing high sensitivity and specificity in the preoperative diagnosis of bowel DIE [7,8]. Treatment of DIE is challenging and requires consideration of pa- tient symptoms, desire for fertility preservation and co-morbidities. First-line medical management consists of combined oral contra- ceptives, progestogens or gonadotrophin-releasing hormone analogues [9,10]. However, surgical management is generally considered the definitive treatment for DIE, particularly in patients who are sympto- matic or have bowel involvement [10–12]. If bowel involvement with DIE is suspected, a multidisciplinary approach involving a colorectal surgeon may be required to reduce the risk of bowel injury and perform bowel resection [10,13,14]. Pre-operatively identifying patients at high risk for bowel resection allows for patient counselling and appropriate resource allocation, particularly pertaining to colorectal surgeon and https://doi.org/10.1016/j.ejrad.2019.108717 Received 21 January 2019; Received in revised form 27 May 2019; Accepted 18 October 2019 ⁎ Corresponding author. E-mail address: ana.brusic2@mh.org.au (A. Brusic). 1 (Present address) Waitemata District Health Board Takapuna, Auckland, New Zealand 0622. 2 Current address: Department of Radiology, Royal Melbourne Hospital, 300 Grattan St, Parkville, Victoria, 3050, Australia. European Journal of Radiology 121 (2019) 108717 0720-048X/ © 2019 Elsevier B.V. All rights reserved. T