Proposed new MRI scoring system of rectosigmoid endometriosis to guide operative planning

Background Rectosigmoid endometriosis (RSE) presents with a diverse array of MRI findings that impact surgical planning. No standardized reporting and data system has been established for RSE. Purpose We propose a novel MRI scoring system designed to predict the likelihood of muscularis propria (MP) involvement in RSE, which would, in turn, influence surgical planning.

The records of patients with bowel endometriosis treated surgically from May 2018 to June 2022 were retrieved. Surgery was classified as partial thickness discoid, full thickness discoid, or segmental resection. Each pre-treatment MRI was scored based on the mutual agreement of two abdominal radiologists (reference score). The MRI score was defined as (1) score 0: no evidence of RSE, (2) score 1: minimal tethering involving the serosal surface without MP involvement, (3) score 2: intermediate soft tissue thickening involving the rectosigmoid colon with indeterminate MP involvement, or (4) score 3: definite mushroom cap sign or definite MP involvement. In the reader study, two radiologists independently scored each exam. The area under the curve (AUC) was evaluated for predicting the need for segmental or full thickness discoid resection.

The cohort consisted of 95 patients (median age: 36 years); 16, 14, 30, and 35 patients had MRI score 0, 1, 2, and 3, respectively. Patients with MRI scores 3 and 2 underwent partial thickness discoid (6% vs. 50%), full thickness discoid (6% vs. 17%), and segmental resection (89% vs. 33%), respectively. All patients with MRI scores 1 or 0 either underwent partial thickness discoid resection or did not undergo rectosigmoid surgery. The AUCs were 92.2%, 84.5% and 93.9% for MRI scores of the reference, reader 1, and 2, respectively.

Our MRI scoring system based on suspected depth of bowel invasion showed good diagnostic performance to predict the type of surgical intervention needed. Similar content being viewed by others Data availability No datasets were generated or analysed during the current study. Abbreviations - RSE: - Rectosigmoid endometriosis - AUC: - Area under the curve - MP: - Muscularis propria

Gerges B, Li W, Leonardi M, Mol BW, Condous G. Optimal imaging modality for detection of rectosigmoid deep endometriosis: systematic review and meta-analysis. Ultrasound Obstet Gynecol. 2021;58(2):190–200. Rousset P, Peyron N, Charlot M, Chateau F, Golfier F, Raudrant D, et al. Bowel endometriosis: preoperative diagnostic accuracy of 3.0-T MR enterography–initial results. Radiology. 2014;273(1):117–24. Rousset P, Buisson G, Lega JC, Charlot M, Gallice C, Cotte E, et al. Rectal endometriosis: predictive MRI signs for segmental bowel resection. Eur Radiol. 2021;31(2):884–94. Jaramillo-Cardoso A, Shenoy-Bhangle AS, VanBuren WM, Schiappacasse G, Menias CO, Mortele KJ. Imaging of gastrointestinal endometriosis: what the radiologist should know. Abdom Radiol (NY). 2020;45(6):1694–710. Jha P, Sakala M, Chamie LP, Feldman M, Hindman N, Huang C, et al. Endometriosis MRI lexicon: consensus statement from the society of abdominal radiology endometriosis disease-focused panel. Abdom Radiol (NY). 2020;45(6):1552–68. Sloss S, Mooney S, Ellett L, Readman E, Ma T, Brouwer R, et al. Preoperative Imaging in Patients with Deep Infiltrating Endometriosis: An Important Aid in Predicting Depth of Infiltration in Rectosigmoid Disease. J Minim Invasive Gynecol. 2022;29(5):633–40. Nezhat C, Li A, Falik R, Copeland D, Razavi G, Shakib A, et al. Bowel endometriosis: diagnosis and management. Am J Obstet Gynecol. 2018;218(6):549–62. International working group of Aagl EE, Wes, Tomassetti C, Johnson NP, Petrozza J, Abrao MS, et al. An International Terminology for Endometriosis, 2021. J Minim Invasive Gynecol. 2021;28(11):1849–59. Quintairos RA, Brito LGO, Farah D, Ribeiro H, Ribeiro P. Conservative versus Radical Surgery for Women with Deep Infiltrating Endometriosis: Systematic Review and Meta-analysis of Bowel Function. J Minim Invasive Gynecol. 2022;29(11):1231–40. Burkett BJ, Cope A, Bartlett DJ, Burnett TL, Jones T, Venkatesh SK, et al. MRI impacts endometriosis management in the setting of image-based multidisciplinary conference: a retrospective analysis. Abdom Radiol (NY). 2020;45(6):1829-39. Keckstein J, Saridogan E, Ulrich UA, Sillem M, Oppelt P, Schweppe KW, et al. The #Enzian classification: A comprehensive non-invasive and surgical description system for endometriosis. Acta Obstet Gynecol Scand. 2021;100(7):1165–75. Montanari E, Bokor A, Szabo G, Kondo W, Trippia CH, Malzoni M, et al. Comparison of #Enzian classification and revised American Society for Reproductive Medicine stages for the description of disease extent in women with deep endometriosis. Hum Reprod. 2022;37(10):2359–65. Thomassin-Naggara I, Monroc M, Chauveau B, Fauconnier A, Verpillat P, Dabi Y, et al. Multicenter External Validation of the Deep Pelvic Endometriosis Index Magnetic Resonance Imaging Score. JAMA Netw Open. 2023;6(5):e2311686. Varela C, Zulfiqar M, Schiappacasse G, Menias CO. ‘Fortune cookie sign’: a variant of mushroom cap sign on T2 weighted MRI for deep sigmoid endometriosis. Abdom Radiol (NY). 2021;46(3):1272–5. Harma K, Binda A, Ith M, Poellinger A, Siegenthaler F, Heverhagen J, et al. Cloverleaf Sign in Pelvic Magnetic Resonance Imaging for Deep Infiltrating Endometriosis: Association With Longer Operation Times, Greater Blood Loss, and Higher Rates of Bowel Resection. Invest Radiol. 2020;55(1):53–9. Yoon JH, Choi D, Jang KT, Kim CK, Kim H, Lee SJ, et al. Deep rectosigmoid endometriosis: “mushroom cap” sign on T2-weighted MR imaging. Abdom Imaging. 2010;35(6):726–31. Scardapane A, Lorusso F, Francavilla M, Bettocchi S, Fascilla FD, Angelelli G, et al. Magnetic Resonance Colonography May Predict the Need for Bowel Resection in Colorectal Endometriosis. Biomed Res Int. 2017;2017:5981217. Brusic A, Esler S, Churilov L, Chowdary P, Sleeman M, Maher P, et al. Deep infiltrating endometriosis: Can magnetic resonance imaging anticipate the need for colorectal surgeon intervention? Eur J Radiol. 2019;121:108717. VanBuren W, Feldman M, Shenoy-Bhangle AS, Sakala MD, Young S, Chamie LP, et al. Radiology State-of-the-art Review: Endometriosis Imaging Interpretation and Reporting. Radiology. 2024;312(3):e233482. Vlek SL, Zwart EAH, Schreurs AMF, van Waesberghe J, Bleeker MCG, Mijatovic V, et al. Deep endometriosis muscular infiltration of the bowel wall: correlation between MRI and histopathology. Clin Radiol. 2023;78(9):661–5. Busard MP, van der Houwen LE, Bleeker MC, Pieters van den Bos IC, Cuesta MA, van Kuijk C, et al. Deep infiltrating endometriosis of the bowel: MR imaging as a method to predict muscular invasion. Abdom Imaging. 2012;37(4):549–57. Horvat N, Carlos Tavares Rocha C, Clemente Oliveira B, Petkovska I, Gollub MJ. MRI of Rectal Cancer: Tumor Staging, Imaging Techniques, and Management. Radiographics. 2019;39(2):367–87. Chamie LP. Ultrasound evaluation of deeply infiltrative endometriosis: technique and interpretation. Abdom Radiol (NY). 2020;45(6):1648–58. Tong A, Cope AG, Waters TL, McDonald JS, VanBuren W. Best Practices: Ultrasound Versus MRI in the Assessment of Pelvic Endometriosis. AJR Am J Roentgenol. 2024. Wild M, Pandhi S, Rendle J, Swift I, Ofuasia E. MRI for the diagnosis and staging of deeply infiltrating endometriosis: a national survey of BSGE accredited endometriosis centres and review of the literature. Br J Radiol. 2020;93(1114):20200690. Loubeyre P, Copercini M, Frossard JL, Wenger JM, Petignat P. Pictorial review: rectosigmoid endometriosis on MRI with gel opacification after rectosigmoid colon cleansing. Clin Imaging. 2012;36(4):295–300.

The authors would like to thank Sherry S. Wang M.D. for preparing the medical illustrations in Figure 2, and Desiree Lanzino PhD for assistance with editing the manuscript. Author information Authors and Affiliations Contributions W.M.V. made the main concept of the scoring system, W.M.V. and H.T. made the study design and served as radiologist readers for the reference, H.T. wrote the main manuscript text, T.L.B. reviewed the surgical history, M.S. reviewed the pathology, S.S.S., L.X., C.C., S.P.S., and C.A.B. served as radiologist readers in the reader studies, H.T. and M.P.J. performed statistical analysis, S.S.S. prepared figure 2. All authors reviewed the manuscript. Corresponding author Ethics declarations Conflict of interest The authors declare no competing interests. Additional information Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Electronic supplementary material Below is the link to the electronic supplementary material. Rights and permissions Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law. About this article Cite this article Takahashi, H., Burnett, T., Shahi, M. et al. Proposed new MRI scoring system of rectosigmoid endometriosis to guide operative planning. Abdom Radiol 50, 6064–6075 (2025). https://doi.org/10.1007/s00261-025-05021-8 Received: Revised: Accepted: Published: Version of record: Issue date: DOI: https://doi.org/10.1007/s00261-025-05021-8