Proposed New MRI Scoring System of Rectosigmoid Endometriosis to Guide Operative Planning

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Burnett, Maryam Shahi, Sherry S. Wang, and 10 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6336241/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 May, 2025 Read the published version in Abdominal Radiology → Version 1 posted 7 You are reading this latest preprint version Abstract 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. Material and Methods: 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. Results: 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. Conclusion: Our MRI scoring system based on suspected depth of bowel invasion showed good diagnostic performance to predict the type of surgical intervention needed. Summary Statement This novel MRI scoring system for rectosigmoid endometriosis is a concise and qualitative scale based on suspected depth of bowel wall invasion to best guide operative planning. Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Key Results Our proposed MRI scoring system has high diagnostic performance in predicting the need for segmental or full thickness discoid resection (AUC: 84.5-93.9%). Our MRI scoring system showed moderate to excellent inter-observer agreement (squared kappa: 0.71-0.82). Quantitative parameters correlated well with the qualitative MRI score but showed greater interreader variability. Combined use of MRI score and quantitative measurement is recommended for standardization of reporting. Introduction MRI is one of the best modalities to diagnose rectosigmoid endometriosis (RSE) (1–5), which manifests as a broad-spectrum of findings ranging from serosal surface disease to deep bowel involvement (3, 6). Surgical strategies for deep endometriosis of the bowel, defined as invasion into muscularis propria (MP), vary depending on the depth of bowel invasion. The most conservative surgical approach is partial thickness discoid resection (previously called rectal shaving) (6–8), in which the RSE lesion is removed while leaving the bowel mucosa and a portion of the muscularis intact (7). This approach is chosen for lesions with minimal MP involvement and is associated with fewer postoperative complications (6). In full thickness discoid resection, the full thickness of the bowel wall at the site of RSE is removed, and the resultant surgical defect is stapled or sutured (7). Full thickness discoid resection can be used for a single site of deep disease less than 3 cm in length and less than 50% in circumference (7). Segmental resection, including low anterior resection and sigmoidectomy, is performed for RSE lesions beyond the criteria for full thickness discoid resection or multifocal lesions (7), and is associated with a greater number of post-operative complications (9). The need for a universal grading system of RSE on MRI to aid in surgical planning was identified through a weekly interdisciplinary conference in our institution (lead by authors W.M.V. and T.L.B.) (10). Although previous studies propose a scoring system to assess the degree of endometriosis invasion (11–13), no widely accepted scoring system for RSE exists. The "mushroom cap sign” is the most common terminology to describe deep bowel endometriosis, representing heterogeneous low T2-weighted signal intensity of the hypertrophic MP, covered with high T2-weighted signal intensity of the mucosa and submucosa (14–16). However, we have encountered a considerable number of RSE lesions without a “mushroom cap sign” that had MP involvement on surgical pathology. Previous studies have focused on the quantitative measurement of RSE lesions on MRI to predict the type of surgery required for complete excision of the disease (3, 17, 18). However, quantitative-based measurement may fail due to variability in measurement techniques between readers and growth characteristics of the lesion. The purpose of the current study was to propose a new MRI scoring system for RSE that is beneficial in operative planning and based on pathologic depth of invasion as it pertains to MRI. Materials and Methods Patient Acquisition Our institutional review board approved this Health Insurance Portability and Accountability Act-compliant, retrospective study. All patients had previously consented to the use of their medical records for research purposes. Between May 2018 and June 2022, the records of female patients with endometriosis who underwent bowel surgery at our institution and had pelvis MRI up to 180 days before surgery were retrieved. Surgery type was identified on chart review by mutual agreement of an abdominal radiologist and a gynecologist. The cohort was divided into two groups. Into two groups: The case group contained patients who had RSE surgery including (1) partial thickness discoid resection, (2) full thickness discoid resection, or (3) segmental resection, including low anterior resection and sigmoidectomy; the control group contained patients who had bowel surgery but did not undergo RSE surgery because no recto-sigmoid involvement was seen during a planned surgery. Ninety-five patients (77 case and 18 control) were enrolled in our study. Patient enrollment details are described in Fig. 1 . MRI Technique MRI was performed with a 3.0-T scanner at our institution (Signa: GE Healthcare, Discovery: GE Healthcare or Skyra: Siemens). All MRI examination protocols (Table 1 ) included at a minimum axial, sagittal, and coronal T2-weighted images, axial diffusion weighted images, axial in- and opposed-phase chemical shift images, and axial and sagittal with fat saturation T1-weighted images before and after administration of intravenous contrast agents (Gadavist, Bayer) (19). Sixty cc of vaginal gel and 1 mg of subcutaneous glucagon were administered before scanning. Image Analysis MRI Score MRI score was defined as follows, with representative lesions and schemes illustrated in Fig. 2 : MRI score 0: no evidence of RSE. MRI score 1: minimal tethering involving the serosal surface of the rectosigmoid colon, consistent with absent imaging evidence of MP involvement. MRI score 2: intermediate thickening and/or soft tissue involving the rectosigmoid colon with relative broad base abutment but without findings of mushroom cap sign, consistent with indeterminate evidence of MP involvement. MRI score 3: definite mushroom cap sign, consistent with definite imaging evidence of MP involvement. Reference MRI Score All 95 MRIs were reviewed by two abdominal radiologists (1.5 years and 9.5 years of experience), and each reference MRI score was decided through joint review of the imaging. Per-patient Reader Study All 95 MRIs were independently evaluated and scored by two abdominal radiologists (reader 1 with 16 years of experience and reader 2 with 9.5 years of experience) on a Digital Imaging and Communications in Medicine viewer (Visage 7, Visage Imaging). All MRI images were anonymized, blinded, and presented in random order. If there were multiple RSE lesions, the dominant rectosigmoid lesion was used as the representative lesion with the readers expected to describe the deepest layer of suspected involvement. Small bowel endometriosis or endometriosis involving the large bowel outside the rectosigmoid colon was not scored. The readers were instructed to look at three planes of T2-weighted images with optimizing windowing and leveling to assess the degree of bowel involvement. The readers were allowed to correlate findings on other sequences. Per-lesion Reader Study Seventy-nine patients with a reference MRI score of 1, 2, or 3 were retrieved. Three readers (reader X with 6 years of experience, reader Y with 4 months of experience, and reader Z with 2 years of experience) were instructed to evaluate the single dominant lesion in each exam annotated in the separate instruction slides. Thus, the readers did not perform a search task. The MRI score was evaluated in the same manner as the per-patient reader study. The lesion length, thickness, and transverse axis were measured using a previously reported method (3). Thickness in lesions with MRI score 1 was considered negligible and reported as 0. Three planes of T2 weighted images were used to obtain the maximum measurement of each parameter. The measurement methods are illustrated in Supplementary Fig. 1 . Pathology The depth of invasion was available for patients who underwent full thickness discoid resection or segmental resection. For 9 patients whose depth of invasion was unclear, the surgical specimen was reevaluated by a pathologist. Statistical Analysis Receiver operation characteristics were applied to evaluate the area under the curve (AUC) of the image interpretation. The sensitivity and specificity were calculated in per-patient analysis. The interobserver agreement was evaluated by using kappa statistics with quadratic weighting and interclass correlation. The differences between variables among different MRI scores were assessed by one-way Analysis of Variance testing. Under-call or over-call cases were defined by a reader’s score 2 or more different from the reference score on the patient-level reader study. Results were considered statistically significant at p values of < 0.05. All data were analyzed using the statistical software R (version 3.6.1). Results The final cohort of 95 patients (median age: 36 years [range 20- 54]) included 77 who underwent RSE surgery and 18 who underwent bowel surgery without RSE surgery ( Figure 1 ). Characteristics of the patients and lesions are summarized in Table 2 and Figure 3 . The median interval between MRI and endometriosis surgery was 75 days (range: 6 to 177 days). There were 16, 14, 30, and 35 patients who had MRI scores of 0, 1, 2, and 3, respectively. All patients with MRI scores 0 or 1 either underwent partial thickness discoid surgery or did not undergo RSE surgery. Of those with MRI score 2, 33% (10/30), 17% (5/30), and 50% (15/30) underwent segmental, full thickness discoid, and partial thickness discoid resection, respectively. Of those with MRI score 3, 89% (31/35), 6% (2/35), and 6% (2/35) underwent segmental, full thickness discoid, and partial thickness discoid resection, respectively. The depth of involvement in the pathologic specimen was confirmed in 15 patients with MRI score 2 and 33 patients with MRI score 3. Invasion of the MP or greater was seen in 90% (12/15) of patients with MRI score 2 and 100% (33/33) of patients with MRI score 3. Per-patient Reader Study : Diagnostic performance of the reference MRI score and two independent radiologist readers is shown in Figure 4 . Interobserver agreements (kappa) were 0.82 (p < 0.001) between reader 1 and the reference, 0.72 (p < 0.001) between reader 2 and the reference, and 0.71 (p < 0.001) between readers 1 and 2. AUCs for predicting the need of segmental or full thickness discoid resection were 92.2%, 84.5%, and 93.9% in the reference, reader 1, and reader 2, respectively ( Figure 4 ). Comparison of MRI scores between the reference and radiologist readers is summarized in Table 3 . Three and 0 under-call cases were identified in reader 1 and 2, respectively. In the three identified cases, the RSE lesions were undetected by reader 1 (false-negative), two were in the sigmoid colon ( Supplement Figure 2 ), and the other was located between the rectum and vaginal cuff after hysterectomy. Both readers 1 and 2 had one overcall case, both of which were caused by pseudo-lesions (false-positive). Loculated ascites near the serosal soft tissue tethering about the rectosigmoid colon was over-called by reader 1 as an MRI score of 3. Partial volume effect of the sigmoid colon wall was over-called by reader 2 as MRI score 2 ( Supplement Figure 3 ). Per-lesion Reader Study : Interobserver agreements (kappa) of the MRI score between readers and the reference were 0.74, 0.63, and 0.58 in Readers X, Y, and Z, respectively. The results are described in Figure 5 and Table 4 . The higher the reference MRI score, the larger all quantitative measurements (i.e. length, transverse, and thickness) were, with the differences showing statistical significance for all three readers (p < 0.001). The medians for length by the three readers were 0-10.5 mm, 10-25.5 mm, and 31-41 mm in the reference MRI score of 1, 2, and 3, respectively. The medians for transverse by the three readers were 0-8.5 mm, 7-13.5 mm, and 12-22 mm in the reference MRI score of 1, 2, and 3, respectively. The medians for thickness by the three readers were 0-8 mm, 4-15 mm, and 11-25 mm in the reference MRI score of 1, 2, and 3, respectively. Intraclass correlation among the three readers was 0.59 for length, 0.42 for transverse, and 0.31 for thickness. Discussion Our proposed MRI scoring system has high diagnostic performance in predicting the need for segmental or full thickness discoid resection (AUC: 84.5-93.9) and shows excellent inter-observer agreement (squared kappa: 0.71-0.82). MRI score correlated well with the quantitative measurements (i.e. length, transverse, and thickness) on the per-lesion reading study. The proposed algorithmic approach to assess MRI score is illustrated in Figure 6. It is advisable to evaluate the MRI score while predicting the degree of MP invasion (20, 21). RSE lesions extend from the subserosa towards the mucosa, which is the opposite direction of growth when compared to colonic cancer, which extends from the mucosa toward the subserosa (22). If the lesions appear to be confined to the serosal surface or superficial layer of subserosa, the MRI score should be 1. These lesions commonly appear as T2-weighted hypointense bands of tissue tethering along the rectosigmoid surface without forming a mass or broad abutment with the serosal surface of the rectosigmoid colon. If the lesions appear to be mushroom cap morphology, this is highly suggestive of MP or greater involvement, and therefore MRI score 3 is given. Lesions that do not belong to either categories 1 or 3 are given MRI score 2. We expect that lesions with MRI score 2 should have at least subserosal involvement but are indeterminate for MP involvement and may have non-specific bowel wall thickening with relatively broad-base abutment. Lesions with MRI score 2 represent the greatest insight in our research and are the most problematic for surgical planning. Although surgeons should be alerted to the possibility of segmental or full thickness discoid resection in the case of MRI score 2, it could result in an overestimation. For example, in the current study, 50% of patients with MRI score 2 were treated with partial thickness discoid resection. Transvaginal ultrasound should help to more accurately classify MRI score 2 lesions. This can be achieved by the higher spatial resolution of transvaginal ultrasound but must also be performed with bowel preparation and a specialized protocol (23, 24). Our MRI score correlated well with quantitative parameters, but quantitative measurements were subject to inconsistencies among readers (ICC:0.31-0.59). The threshold to predict the need for segmental resection has been suggested to be 14 mm in thickness (3). In our study, 64.6%, 86.1%, and 31.5% of lesions measured below 14 mm in thickness by readers X, Y, and Z, respectively, suggesting that a clear quantitative cut-off value may be difficult given inter-reader variability. We recommend combined use of the qualitative MRI score along with quantitative measurement for standardization of reporting. Our recommendations of quantitative measurement for each MRI score are illustrated in Figure 6. Both under-call and over-call errors may be inversely correlated with reader experience. The patient-level study performed by two radiologists with many years of endometriosis-specific experience showed excellent interreader agreement for MRI scoring (0.71-0.82), while the lesion-level study performed by three early-to-middle carrier radiologists with lesser endometriosis education showed moderate agreement for MRI scoring (0.58-0.74) despite the lack of a lesion detection task. Of note, the kappa values of these two reader studies are not directly comparable. The impact of radiologist experience on the MRI score should be further investigated, however suggests additional educational efforts may be beneficial. Search failure could be another cause of errors. Undercalling errors can take place when RSE lesions are found in unexpected locations depending on uterine positioning or postoperative changes. Overcall errors are often attributable to pseudo-lesions, such as artifacts, bowel wall thickening, or peritoneal reflection thickening that may mimic RSE lesions. The present study has several limitations. First, this was a retrospective, single-institutional study. The retrospective study design was mandatory given that a prospective study would impact the choice of surgery and potentially bias the results. External validation is necessary to assess the feasibility of our MRI score with different MRI protocols and patient preparations (25). At our institution, all MRIs are performed on a 3.0 Tesla scanner and are protocolled with vaginal gel and subcutaneous glucagon injection and without rectal gel. While some outside centers administer rectal gel to improve visualization of RSE lesions (26), this is not protocol at our institution as it may overdistend the rectum, obliterate the posterior cul-de-sac, and be associated with problematic artifacts. Furthermore, we did not have pathological confirmation for control cases who appropriately did not undergo RSE surgery due to negative rectosigmoid assessment by the surgeon at the time of endometriosis surgery. Future directions include investigating if the MRI score is applicable to lesions above the rectosigmoid colon. In conclusion, our MRI scoring system for rectosigmoid endometriosis is a concise and qualitative scale based on suspected depth of bowel wall invasion and correlates with pathologic depth of invasion. This alignment allows the MRI scoring system to serve as a valuable guide for optimizing operative planning. Abbreviations RSE Rectosigmoid endometriosis AUC Area under the curve MP Muscularis propria Declarations Author Contribution 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. Acknowledgement 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. References 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. Tables Table 1. MRI Protocol for Endometriosis Sequence Plane Thickness (mm) Comments T2WI TSE without fat suppression Axial, sagittal and coronal 3-5 mm (axial), 4 mm (sagittal and coronal) T1WI in-phase and out-of-phase GRE or Dixon Axial 5 mm T1WI with fat suppression without intravenous contrast material Axial and sagittal 3 mm (axial), 3-4 mm (sagittal) T1WI with intravenous contrast material Axial and sagittal 3 mm (axial), 3-4 mm (sagittal) Diffusion-weighted imaging Axial 4-5 mm b value = 0, 50, 1000 sec/mm 2 T2WI fast spine echo with fat saturation Axial T2WI echo-planar fast spine echo Axial Large FOV to include kidneys FOV: field of view, GRE: gradient echo, T1WI: T1 weighted imaging, T2WI: T2 weighted imaging Table 2. Patient and Lesion Characteristics Total Case (w/ RSE surgery) Control (w/o RSE surgery) Patient number 95 77 18 Age [years] † 36 (20 to 54) 37 (22 to 54) 32 (20 to 44) Interval between MRI and endometriosis surgery [days] † 75 (6 to 177) 76 (6 to 177) 72 (10 to 162) MRI score (reference) [number] MRI score 0 MRI score 1 MRI score 2 MRI score 3 16 14 30 35 2 10 30 35 14 4 0 0 Types of surgery [number] Segmental resection Low anterior resection Sigmoidectomy Full thickness discoid resection Partial thickness discoid resection 41 32 9 7 29 41 32 9 7 29 N/A N/A N/A N/A N/A Depth of invasion (for patients who underwent segmental resection or full thickness discoid resection only) [number] Submucosa/mucosa Muscularis propria Serosa No involvement 24 21 1 2 24 21 1 2 N/A N/A N/A N/A †median (minimum to maximum) Table 3. Comparison of MRI Scores Between the Reader Study and the Reference Score in the Per-patient Reader study Reference score MRI score 0 MRI score 1 MRI score 2 MRI score 3 Reader 1 MRI score 0 5 2 1 † 1 † MRI score 1 11 7 5 1 † MRI score 2 0 * 4 13 6 MRI score 3 0 * 1 * 11 27 Reader 2 MRI score 0 7 1 0 † 0 † MRI score 1 8 7 5 0 † MRI score 2 1 * 6 13 3 MRI score 3 0 * 0 * 12 32 †Under-call case: the cases with reader’s score 2 or more lower than the reference score. * Over-call cases: the cases with reader’s score 2 or more higher than the reference score. Table 4. Quantitative Parameters Measured by Three Readers in the Per-lesion Reader study Reader X Reader Y Reader Z Interreader agreement** Length (mm) Reference MRI score 1† Reference MRI score 2† Reference MRI score 3† P value – difference among MRI scores* 4.5 (0-7) 10 (2-50) 31 (3-66) <0.001 0 (0-33) 21 (0-78) 30 (0-72) <0.001 10.5 (4-33) 25.5 (6-100) 41 (11-72) <0.001 0.59 Transverse (mm) Reference MRI score 1† Reference MRI score 2† Reference MRI score 3† P value – difference among MRI scores* 3 (0-9) 11 (3-27) 18 (5-31) <0.001 0 (0-13) 7 (0-25) 12 (0-29) <0.001 8.5 (4-27) 13.5 (5-40) 22 (8-46) <0.001 0.42 Thickness (mm) Reference MRI score 1† Reference MRI score 2† Reference MRI score 3† P value – difference among MRI scores* 0 (0-11) 8 (3-21) 14 (5-29) <0.001 0(0-12) 4 (0-19) 11 (0-17) <0.001 8 (4-22) 15 (6-64) 25 (11-49) <0.001 0.31 †median (minimum to maximum). * The differences of values among MRI scores 1, 2, and 3 were assessed by one-way Analysis of Variance. P<0.05 was considered statistically significant. ** Interreader agreement was assessed by intraclass correlation. Additional Declarations No competing interests reported. Supplementary Files BowelEndoRevTableFin.docx Supplementary Figure 1. Illustrations of quantitative measurements. (a) Sagittal T2-weighted images illustrate the length measurement using a linear distance tool to emulate measurements. (b) Axial T2-weighted images illustrate the measurement of the transverse axis. (c) Axial T2-weighted images illustrate the thickness measurement. Of note, thickness in lesions with MRI score 1 was considered negligible and reported as 0. Three planes of T2 weighted images were used to obtain the maximum measurement of each parameter. BowelEndoRevFinFigSup.docx Supplementary Figure 2. A 39-year-old female with an under-call lesion. A sagittal T2-weighted image (a) and a coronal T2-weighted image (b) demonstrated a mushroom cap lesion involving the distal sigmoid colon (arrow). Patient-level MRI score was 3, 0, and 3 by the reference, reader 1, and reader 2, respectively. This lesion was undetected by reader 1 (under-call lesion). The patient underwent sigmoid resection. The surgical specimen showed muscularis propria involvement. Cite Share Download PDF Status: Published Journal Publication published 29 May, 2025 Read the published version in Abdominal Radiology → Version 1 posted Editorial decision: Revision requested 09 May, 2025 Reviews received at journal 23 Apr, 2025 Reviewers agreed at journal 14 Apr, 2025 Reviewers invited by journal 03 Apr, 2025 Editor assigned by journal 03 Apr, 2025 Submission checks completed at journal 03 Apr, 2025 First submitted to journal 29 Mar, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6336241","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":447043872,"identity":"c3bf28ed-fb78-4876-8584-640178f6f1d9","order_by":0,"name":"Hiroaki Takahashi","email":"","orcid":"","institution":"Mayo Clinic","correspondingAuthor":false,"prefix":"","firstName":"Hiroaki","middleName":"","lastName":"Takahashi","suffix":""},{"id":447043873,"identity":"2e37c01a-5f39-49ce-ba0d-cab5bdb08469","order_by":1,"name":"Tatnai L. Burnett","email":"","orcid":"","institution":"Mayo Clinic","correspondingAuthor":false,"prefix":"","firstName":"Tatnai","middleName":"L.","lastName":"Burnett","suffix":""},{"id":447043874,"identity":"ea3c5ab7-2049-4d6e-9b63-0f6d9ee80ef8","order_by":2,"name":"Maryam Shahi","email":"","orcid":"","institution":"Mayo Clinic","correspondingAuthor":false,"prefix":"","firstName":"Maryam","middleName":"","lastName":"Shahi","suffix":""},{"id":447043875,"identity":"8ae3e256-d697-4911-bb63-9611abb52e8f","order_by":3,"name":"Sherry S. Wang","email":"","orcid":"","institution":"Mayo Clinic","correspondingAuthor":false,"prefix":"","firstName":"Sherry","middleName":"S.","lastName":"Wang","suffix":""},{"id":447043876,"identity":"acb912d7-1240-4ccb-ba1a-1d47a6431d26","order_by":4,"name":"Lekui Xiao","email":"","orcid":"","institution":"Mayo Clinic","correspondingAuthor":false,"prefix":"","firstName":"Lekui","middleName":"","lastName":"Xiao","suffix":""},{"id":447043877,"identity":"79626410-390f-4422-b11f-b73e3d132a66","order_by":5,"name":"Ceylan Colak","email":"","orcid":"","institution":"Mayo Clinic","correspondingAuthor":false,"prefix":"","firstName":"Ceylan","middleName":"","lastName":"Colak","suffix":""},{"id":447043878,"identity":"025dd2dd-0e19-4297-89bb-793dafe96a39","order_by":6,"name":"Shannon P. Sheedy","email":"","orcid":"","institution":"Mayo Clinic","correspondingAuthor":false,"prefix":"","firstName":"Shannon","middleName":"P.","lastName":"Sheedy","suffix":""},{"id":447043879,"identity":"5764d966-42c3-4a68-9641-e425c019c3de","order_by":7,"name":"Candice A. Bookwalter","email":"","orcid":"","institution":"Mayo Clinic","correspondingAuthor":false,"prefix":"","firstName":"Candice","middleName":"A.","lastName":"Bookwalter","suffix":""},{"id":447043880,"identity":"24c9215b-a1da-4f98-8d5e-a213cb6c6c1c","order_by":8,"name":"Priyanka Jha","email":"","orcid":"","institution":"Stanford University","correspondingAuthor":false,"prefix":"","firstName":"Priyanka","middleName":"","lastName":"Jha","suffix":""},{"id":447043881,"identity":"4ca6fed1-67eb-4025-bd59-8d9c7ccddc8f","order_by":9,"name":"Myra K, Feldman","email":"","orcid":"","institution":"Cleveland Clinic","correspondingAuthor":false,"prefix":"","firstName":"Feldman","middleName":"Myra","lastName":"K","suffix":""},{"id":447043882,"identity":"9fe29265-27c8-440d-94b2-b3b70a889bad","order_by":10,"name":"Zaraq Khan","email":"","orcid":"","institution":"Mayo Clinic","correspondingAuthor":false,"prefix":"","firstName":"Zaraq","middleName":"","lastName":"Khan","suffix":""},{"id":447043883,"identity":"52554071-675b-4762-bc38-061d985f4765","order_by":11,"name":"Adela G. Cope","email":"","orcid":"","institution":"Mayo Clinic","correspondingAuthor":false,"prefix":"","firstName":"Adela","middleName":"G.","lastName":"Cope","suffix":""},{"id":447043884,"identity":"f2d853fa-f4e8-4bd6-8365-233411e3b9d2","order_by":12,"name":"Matthew P. Johnson","email":"","orcid":"","institution":"Mayo Clinic","correspondingAuthor":false,"prefix":"","firstName":"Matthew","middleName":"P.","lastName":"Johnson","suffix":""},{"id":447043885,"identity":"f1405370-e696-4d83-90a0-5098806f89a7","order_by":13,"name":"Wendaline M. VanBuren","email":"data:image/png;base64,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","orcid":"","institution":"Mayo Clinic","correspondingAuthor":true,"prefix":"","firstName":"Wendaline","middleName":"M.","lastName":"VanBuren","suffix":""}],"badges":[],"createdAt":"2025-03-30 01:08:03","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6336241/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6336241/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00261-025-05021-8","type":"published","date":"2025-05-29T15:57:22+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":81937370,"identity":"f8303553-5a8e-41d8-8f3f-2939389386fb","added_by":"auto","created_at":"2025-05-05 06:27:45","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":104013,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ePatient enrollment flowchart.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBetween May 2018 and June 2022, 125 female patients with bowel endometriosis were enrolled in this \u0026nbsp;institutional review board approved Health Insurance Portability and Accountability Act-compliant, retrospective study. All patients had previously consented to the use of their medical records for research purposes. Between May 2018 and June 2022, 125 female patients with endometriosis who underwent bowel surgery (including colon, rectum, small bowel and appendix) at our institution were retrieved. Among this group, 97 had a “rectal” or “sigmoid” specimen, and 86 of these underwent rectosigmoid endometriosis (RSE) surgery including segmentectomy (sigmoid resection or low anterior resection), full thickness discoid resection, or partial thickness discoid resection. The 11 patients with rectal serosal resection were excluded. Out of 86 patients, 77 had pelvic MRI within 180 days before surgery and were enrolled as the case group (i.e., patients who underwent RSE surgery). Among the 28 patients whose pathology report did not contain “rectal” or “sigmoid” specimen, 18 patients underwent pelvic MRI within 180 days before surgery and were enrolled as the control group (i.e., patients who did not undergo RSE surgery due to negative rectosigmoid involvement during the endometriosis surgery; these patients underwent small bowel surgery or appendectomy for endometriosis involvement). The final cohort consisted of 95 patients (median age: 36 years [range 20 to 54]) and included 77 patients who underwent RSE surgery and 18 patients who did not undergo RSE surgery due to negative rectosigmoid involvement during endometriosis surgery.\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6336241/v1/39ca816b3f2ffbf417864c92.jpg"},{"id":81938232,"identity":"a75ecf9b-c605-474c-9f24-4846313f8225","added_by":"auto","created_at":"2025-05-05 06:35:45","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":541013,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eRepresentative illustrations of RSE endometriosis with each MRI score.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMRI score was defined as follows: \u003cstrong\u003e(a)\u003c/strong\u003e MRI score 0: no evidence of RSE. \u003cstrong\u003e(b)\u003c/strong\u003e MRI score 1: minimal tethering involving the serosal surface of the rectosigmoid colon, consistent with absent imaging evidence of muscularis propria (MP) involvement. \u003cstrong\u003e(c) \u003c/strong\u003eMRI score 2: intermediate thickening and/or soft tissue involving the rectosigmoid colon with relative broad base abutment but without findings of mushroom cap sign, consistent with indeterminate evidence of MP involvement. \u003cstrong\u003e(d)\u003c/strong\u003e MRI score 3: definite mushroom cap sign, consistent with definite imaging evidence of MP involvement.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6336241/v1/533bee436b1fcbea5c3cc6a7.jpg"},{"id":81938239,"identity":"44b5162a-d165-4ca9-be22-cff26ca721d9","added_by":"auto","created_at":"2025-05-05 06:35:45","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":54506,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSurgery type and depth of invasion for each MRI score.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere were 16, 14, 30, and 35 patients who had MRI score 0, 1, 2, and 3, respectively. All patients with MRI scores 0 or 1 either underwent partial thickness discoid resection or did not undergo RSE surgery. Of the patients with MRI score 2, 33% (10/30), 17% (5/30), and 50% (15/30) underwent segmental, full thickness discoid, and partial thickness discoid resection, respectively. Of the patients with MRI score 3, 89% (31/35), 6% (2/35), and 6% (2/35) underwent segmental, full thickness discoid, and partial thickness discoid resection, respectively. The depth of involvement in pathology specimen was confirmed in 15 patients with MRI score 2 and 33 patients with MRI score 3. Muscularis propria or more invasion was seen in 90 % (12/15) of patients with MRI score 2, and 100% (33/33) of patients with MRI score 3.\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6336241/v1/f9912b664cbd8ab002745f6a.jpg"},{"id":81937372,"identity":"147e6258-462e-411c-9618-45f1cd52d358","added_by":"auto","created_at":"2025-05-05 06:27:45","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":66740,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eDiagnostic performance of MRI score to predict the need of surgery in the per-patient reader study.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6336241/v1/4470e7a14b621686485c0dd7.jpg"},{"id":81937376,"identity":"f898b8e0-1727-47dc-a9e5-6b70f3593aaa","added_by":"auto","created_at":"2025-05-05 06:27:45","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":100970,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eBox and jitter plots of quantitative parameters measured by three readers in the per-lesion reader study.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6336241/v1/4a7d7d2a71306a6197dc6cb9.jpg"},{"id":81938234,"identity":"e198c6d3-57a5-4eb7-9ec9-0d472c3d258b","added_by":"auto","created_at":"2025-05-05 06:35:45","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":73988,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eAlgorithmic approach to assess MRI score and our recommendation of quantitative measurement for each MRI score.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe lesions with MRI score 1 appear as T2-weighted hypointense bands of tissue tethering along the rectosigmoid surface without forming a mass or broad abutment with the serosal surface of the rectosigmoid colon. We do not recommend to report quantitative measurement for the lesions with MRI score 1 because they will not be treated by full thickness discoid resection or segmental resection. If the lesions appear to be mushroom cap morphology, this is highly suggestive of MP or greater involvement, and therefore MRI score 3 is given. We recommend to report length and transverse for the lesions with MRI score 3. Circumference of the rectal involvement is also recommended to help surgeons to determine the surgical strategy – if the lesions involve the rectum with greater than 50%, full thickness discoid resection should be avoided due to the increased risk of postsurgical leak. Thickness measurements may be optional as rectal lesions are often in continuity with retrocervical disease and the AP dimension is not well delineated; this measurement is prone to interreader variability and does not impact management. Lesions that do not belong to either categories 1 or 3 are given MRI score 2. For lesions with MRI score 2, we recommend measuring the length, and if applicable, transverse and thickness. Transvaginal ultrasound with bowel preparation should help to more accurately classify MRI score 2 lesions. For lesions with MRI score 2 and 3, reporting the distance from the anorectal junction is useful to identify the location of the lesion during the surgery. Although not part of this study, multiplicity of lesions should be described.\u003c/p\u003e","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6336241/v1/7ccbb789bac89676eb2d93e1.jpg"},{"id":83783197,"identity":"e5b4e2f2-6cfd-4e9d-8d43-1cd041a09da2","added_by":"auto","created_at":"2025-06-02 16:11:04","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2010167,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6336241/v1/2db8742e-5cdc-4de9-8a5e-ca4f52a8c7ef.pdf"},{"id":81938236,"identity":"b56e711e-22a3-4847-a309-75e2437c4f98","added_by":"auto","created_at":"2025-05-05 06:35:45","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":50042,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSupplementary Figure 1.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIllustrations of quantitative measurements. (a) Sagittal T2-weighted images illustrate the length measurement using a linear distance tool to emulate measurements. (b) Axial T2-weighted images illustrate the measurement of the transverse axis. (c) Axial T2-weighted images illustrate the thickness measurement. Of note, thickness in lesions with MRI score 1 was considered negligible and reported as 0. Three planes of T2 weighted images were used to obtain the maximum measurement of each parameter.\u003c/p\u003e","description":"","filename":"BowelEndoRevTableFin.docx","url":"https://assets-eu.researchsquare.com/files/rs-6336241/v1/4a25ca802275c8078e10f49b.docx"},{"id":81938250,"identity":"67ea9a7e-2c42-49ad-af3f-31ba8c365888","added_by":"auto","created_at":"2025-05-05 06:35:48","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":2483616,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSupplementary Figure 2. A 39-year-old female with an under-call lesion.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA sagittal T2-weighted image (a) and a coronal T2-weighted image (b) demonstrated a mushroom cap lesion involving the distal sigmoid colon (arrow). Patient-level MRI score was 3, 0, and 3 by the reference, reader 1, and reader 2, respectively. This lesion was undetected by reader 1 (under-call lesion). The patient underwent sigmoid resection. The surgical specimen showed muscularis propria involvement.\u003c/p\u003e","description":"","filename":"BowelEndoRevFinFigSup.docx","url":"https://assets-eu.researchsquare.com/files/rs-6336241/v1/d8ebcf700a7ea975bc62d43a.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Proposed New MRI Scoring System of Rectosigmoid Endometriosis to Guide Operative Planning","fulltext":[{"header":"Key Results ","content":"\u003col\u003e\n \u003cli\u003eOur proposed MRI scoring system has high diagnostic performance in predicting the need for segmental or full thickness discoid resection (AUC: 84.5-93.9%).\u003c/li\u003e\n \u003cli\u003eOur MRI scoring system showed moderate to excellent inter-observer agreement (squared kappa: 0.71-0.82).\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eQuantitative parameters correlated well with the qualitative MRI score but showed greater interreader variability. Combined use of MRI score and quantitative measurement is recommended for standardization of reporting.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Introduction","content":"\u003cp\u003eMRI is one of the best modalities to diagnose rectosigmoid endometriosis (RSE) (1\u0026ndash;5), which manifests as a broad-spectrum of findings ranging from serosal surface disease to deep bowel involvement (3, 6). Surgical strategies for deep endometriosis of the bowel, defined as invasion into muscularis propria (MP), vary depending on the depth of bowel invasion. The most conservative surgical approach is partial thickness discoid resection (previously called rectal shaving) (6\u0026ndash;8), in which the RSE lesion is removed while leaving the bowel mucosa and a portion of the muscularis intact (7). This approach is chosen for lesions with minimal MP involvement and is associated with fewer postoperative complications (6). In full thickness discoid resection, the full thickness of the bowel wall at the site of RSE is removed, and the resultant surgical defect is stapled or sutured (7). Full thickness discoid resection can be used for a single site of deep disease less than 3 cm in length and less than 50% in circumference (7). Segmental resection, including low anterior resection and sigmoidectomy, is performed for RSE lesions beyond the criteria for full thickness discoid resection or multifocal lesions (7), and is associated with a greater number of post-operative complications (9).\u003c/p\u003e \u003cp\u003eThe need for a universal grading system of RSE on MRI to aid in surgical planning was identified through a weekly interdisciplinary conference in our institution (lead by authors W.M.V. and T.L.B.) (10). Although previous studies propose a scoring system to assess the degree of endometriosis invasion (11\u0026ndash;13), no widely accepted scoring system for RSE exists. The \"mushroom cap sign\u0026rdquo; is the most common terminology to describe deep bowel endometriosis, representing heterogeneous low T2-weighted signal intensity of the hypertrophic MP, covered with high T2-weighted signal intensity of the mucosa and submucosa (14\u0026ndash;16). However, we have encountered a considerable number of RSE lesions without a \u0026ldquo;mushroom cap sign\u0026rdquo; that had MP involvement on surgical pathology. Previous studies have focused on the quantitative measurement of RSE lesions on MRI to predict the type of surgery required for complete excision of the disease (3, 17, 18). However, quantitative-based measurement may fail due to variability in measurement techniques between readers and growth characteristics of the lesion.\u003c/p\u003e \u003cp\u003eThe purpose of the current study was to propose a new MRI scoring system for RSE that is beneficial in operative planning and based on pathologic depth of invasion as it pertains to MRI.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003ePatient Acquisition\u003c/h2\u003e\n \u003cp\u003eOur institutional review board approved this Health Insurance Portability and Accountability Act-compliant, retrospective study. All patients had previously consented to the use of their medical records for research purposes. Between May 2018 and June 2022, the records of female patients with endometriosis who underwent bowel surgery at our institution and had pelvis MRI up to 180 days before surgery were retrieved. Surgery type was identified on chart review by mutual agreement of an abdominal radiologist and a gynecologist. The cohort was divided into two groups. Into two groups: The case group contained patients who had RSE surgery including (1) partial thickness discoid resection, (2) full thickness discoid resection, or (3) segmental resection, including low anterior resection and sigmoidectomy; the control group contained patients who had bowel surgery but did not undergo RSE surgery because no recto-sigmoid involvement was seen during a planned surgery.\u003c/p\u003e\n \u003cp\u003eNinety-five patients (77 case and 18 control) were enrolled in our study. Patient enrollment details are described in Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n\u003c/div\u003e\n\u003ch3\u003eMRI Technique\u003c/h3\u003e\n\u003cp\u003eMRI was performed with a 3.0-T scanner at our institution (Signa: GE Healthcare, Discovery: GE Healthcare or Skyra: Siemens). All MRI examination protocols (Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e) included at a minimum axial, sagittal, and coronal T2-weighted images, axial diffusion weighted images, axial in- and opposed-phase chemical shift images, and axial and sagittal with fat saturation T1-weighted images before and after administration of intravenous contrast agents (Gadavist, Bayer) (19). Sixty cc of vaginal gel and 1 mg of subcutaneous glucagon were administered before scanning.\u003c/p\u003e\n\u003ch3\u003eImage Analysis\u003c/h3\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\n \u003ch2\u003eMRI Score\u003c/h2\u003e\n \u003cp\u003eMRI score was defined as follows, with representative lesions and schemes illustrated in Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e:\u003c/p\u003e\n \u003cul\u003e\n \u003cli\u003e\n \u003cp\u003eMRI score 0: no evidence of RSE.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003eMRI score 1: minimal tethering involving the serosal surface of the rectosigmoid colon, consistent with absent imaging evidence of MP involvement.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003eMRI score 2: intermediate thickening and/or soft tissue involving the rectosigmoid colon with relative broad base abutment but without findings of mushroom cap sign, consistent with indeterminate evidence of MP involvement.\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003eMRI score 3: definite mushroom cap sign, consistent with definite imaging evidence of MP involvement.\u003c/p\u003e\n \u003c/li\u003e\n \u003c/ul\u003e\n \u003cp\u003e\u003cspan type=\"BoldUnderline\" class=\"BoldUnderline\" name=\"Emphasis\"\u003eReference MRI Score\u003c/span\u003e\u003c/p\u003e\n \u003cp\u003eAll 95 MRIs were reviewed by two abdominal radiologists (1.5 years and 9.5 years of experience), and each reference MRI score was decided through joint review of the imaging.\u003c/p\u003e\n\u003c/div\u003e\n\u003ch3\u003ePer-patient Reader Study\u003c/h3\u003e\n\u003cp\u003eAll 95 MRIs were independently evaluated and scored by two abdominal radiologists (reader 1 with 16 years of experience and reader 2 with 9.5 years of experience) on a Digital Imaging and Communications in Medicine viewer (Visage 7, Visage Imaging). All MRI images were anonymized, blinded, and presented in random order. If there were multiple RSE lesions, the dominant rectosigmoid lesion was used as the representative lesion with the readers expected to describe the deepest layer of suspected involvement. Small bowel endometriosis or endometriosis involving the large bowel outside the rectosigmoid colon was not scored. The readers were instructed to look at three planes of T2-weighted images with optimizing windowing and leveling to assess the degree of bowel involvement. The readers were allowed to correlate findings on other sequences.\u003c/p\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003ePer-lesion Reader Study\u003c/h2\u003e\n \u003cp\u003eSeventy-nine patients with a reference MRI score of 1, 2, or 3 were retrieved. Three readers (reader X with 6 years of experience, reader Y with 4 months of experience, and reader Z with 2 years of experience) were instructed to evaluate the single dominant lesion in each exam annotated in the separate instruction slides. Thus, the readers did not perform a search task. The MRI score was evaluated in the same manner as the per-patient reader study. The lesion length, thickness, and transverse axis were measured using a previously reported method (3). Thickness in lesions with MRI score 1 was considered negligible and reported as 0. Three planes of T2 weighted images were used to obtain the maximum measurement of each parameter. The measurement methods are illustrated in \u003cstrong\u003eSupplementary Fig.\u0026nbsp;1\u003c/strong\u003e.\u003c/p\u003e\n\u003c/div\u003e\n\u003ch3\u003ePathology\u003c/h3\u003e\n\u003cp\u003eThe depth of invasion was available for patients who underwent full thickness discoid resection or segmental resection. For 9 patients whose depth of invasion was unclear, the surgical specimen was reevaluated by a pathologist.\u003c/p\u003e\n\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\n \u003ch2\u003eStatistical Analysis\u003c/h2\u003e\n \u003cp\u003eReceiver operation characteristics were applied to evaluate the area under the curve (AUC) of the image interpretation. The sensitivity and specificity were calculated in per-patient analysis. The interobserver agreement was evaluated by using kappa statistics with quadratic weighting and interclass correlation. The differences between variables among different MRI scores were assessed by one-way Analysis of Variance testing. Under-call or over-call cases were defined by a reader\u0026rsquo;s score 2 or more different from the reference score on the patient-level reader study. Results were considered statistically significant at p values of \u0026lt;\u0026thinsp;0.05. All data were analyzed using the statistical software R (version 3.6.1).\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eThe final cohort of 95 patients (median age: 36 years [range 20- 54]) included 77 who underwent RSE surgery and 18 who underwent bowel surgery without RSE surgery (\u003cstrong\u003eFigure 1\u003c/strong\u003e). Characteristics of the patients and lesions are summarized in \u003cstrong\u003eTable 2 and Figure 3\u003c/strong\u003e. The median interval between MRI and endometriosis surgery was 75 days (range: 6 to 177 days). There were 16, 14, 30, and 35 patients who had MRI scores of 0, 1, 2, and 3, respectively. All patients with MRI scores 0 or 1 either underwent partial thickness discoid surgery or did not undergo RSE surgery. Of those with MRI score 2, 33% (10/30), 17% (5/30), and 50% (15/30) underwent segmental, full thickness discoid, and partial thickness discoid resection, respectively. Of those with MRI score 3, 89% (31/35), 6% (2/35), and 6% (2/35) underwent segmental, full thickness discoid, and partial thickness discoid resection, respectively.\u0026nbsp;The depth of involvement in the pathologic specimen was confirmed in 15 patients with MRI score 2 and 33 patients with MRI score 3. Invasion of the MP or greater was seen in 90% (12/15) of patients with MRI score 2 and 100% (33/33) of patients with MRI score 3.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePer-patient Reader Study\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDiagnostic performance of the reference MRI score and two independent radiologist readers is shown in \u003cstrong\u003eFigure 4\u003c/strong\u003e. Interobserver agreements (kappa) were 0.82 (p \u0026lt; 0.001) between reader 1 and the reference, 0.72 (p \u0026lt; 0.001) between reader 2 and the reference, and 0.71 (p \u0026lt; 0.001) between readers 1 and 2. AUCs for predicting the need of segmental or full thickness discoid resection were 92.2%, 84.5%, and 93.9% in the reference, reader 1, and reader 2, respectively (\u003cstrong\u003eFigure 4\u003c/strong\u003e). \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eComparison of MRI scores between the reference and radiologist readers is summarized in \u003cstrong\u003eTable 3\u003c/strong\u003e. Three and 0 under-call cases were identified in reader 1 and 2, respectively. In the three identified cases, the RSE lesions were undetected by reader 1 (false-negative), two were in the sigmoid colon (\u003cstrong\u003eSupplement Figure 2\u003c/strong\u003e), and the other was located between the rectum and vaginal cuff after hysterectomy. Both readers 1 and 2 had one overcall case, both of which were caused by pseudo-lesions (false-positive). Loculated ascites near the serosal soft tissue tethering about the rectosigmoid colon was over-called by reader 1 as an MRI score of 3. Partial volume effect of the sigmoid colon wall was over-called by reader 2 as MRI score 2 (\u003cstrong\u003eSupplement Figure 3\u003c/strong\u003e).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePer-lesion Reader Study\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInterobserver agreements (kappa) of the MRI score between readers and the reference were 0.74, 0.63, and 0.58 in Readers X, Y, and Z, respectively. The results are described in \u003cstrong\u003eFigure 5\u003c/strong\u003e and \u003cstrong\u003eTable 4\u003c/strong\u003e. The higher the reference MRI score, the larger all quantitative measurements (i.e. length, transverse, and thickness) were, with the differences showing statistical significance for all three readers (p \u0026lt; 0.001). The medians for length by the three readers were 0-10.5 mm, 10-25.5 mm, and 31-41 mm in the reference MRI score of 1, 2, and 3, respectively. The medians for transverse by the three readers were 0-8.5 mm, 7-13.5 mm, and 12-22 mm in the reference MRI score of 1, 2, and 3, respectively. The medians for thickness by the three readers were 0-8 mm, 4-15 mm, and 11-25 mm in the reference MRI score of 1, 2, and 3, respectively. Intraclass correlation among the three readers was 0.59 for length, 0.42 for transverse, and 0.31 for thickness.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur proposed MRI scoring system has high diagnostic performance in predicting the need for segmental or full thickness discoid resection (AUC: 84.5-93.9) and shows excellent inter-observer agreement (squared kappa: 0.71-0.82). MRI score correlated well with the quantitative measurements (i.e. length, transverse, and thickness) on the per-lesion reading study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe proposed algorithmic approach to assess MRI score is illustrated in Figure 6. It is advisable to evaluate the MRI score while predicting the degree of MP invasion (20, 21). RSE lesions extend from the subserosa towards the mucosa, which is the opposite direction of growth when compared to colonic cancer, which extends from the mucosa toward the subserosa (22). If the lesions appear to be confined to the serosal surface or superficial layer of subserosa, the MRI score should be 1. These lesions commonly appear as T2-weighted hypointense bands of tissue tethering along the rectosigmoid surface without forming a mass or broad abutment with the serosal surface of the rectosigmoid colon. If the lesions appear to be mushroom cap morphology, this is highly suggestive of MP or greater involvement, and therefore MRI score 3 is given. Lesions that do not belong to either categories 1 or 3 are given MRI score 2. We expect that lesions with MRI score 2 should have at least subserosal involvement but are indeterminate for MP involvement and may have non-specific bowel wall thickening with relatively broad-base abutment.\u003c/p\u003e\n\u003cp\u003eLesions with MRI score 2 represent the greatest insight in our research and are the most problematic for surgical planning. Although surgeons should be alerted to the possibility of segmental or full thickness discoid resection in the case of MRI score 2, it could result in an overestimation. For example, in the current study, 50% of patients with MRI score 2 were treated with partial thickness discoid resection. Transvaginal ultrasound should help to more accurately classify MRI score 2 lesions. This can be achieved by the higher spatial resolution of transvaginal ultrasound but must also be performed with bowel preparation and a specialized protocol (23, 24).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOur MRI score correlated well with quantitative parameters, but quantitative measurements were subject to inconsistencies among readers (ICC:0.31-0.59). The threshold to predict the need for segmental resection has been suggested to be 14 mm in thickness (3). In our study, 64.6%, 86.1%, and 31.5% of lesions measured below 14 mm in thickness by readers X, Y, and Z, respectively, suggesting that a clear quantitative cut-off value may be difficult given inter-reader variability. We recommend combined use of the qualitative MRI score along with quantitative measurement for standardization of reporting. Our recommendations of quantitative measurement for each MRI score are illustrated in Figure 6.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eBoth under-call and over-call errors may be inversely correlated with reader experience. The patient-level study performed by two radiologists with many years of endometriosis-specific experience showed excellent interreader agreement for MRI scoring (0.71-0.82), while the lesion-level study performed by three early-to-middle carrier radiologists with lesser endometriosis education showed moderate agreement for MRI scoring (0.58-0.74) despite the lack of a lesion detection task. Of note, the kappa values of these two reader studies are not directly comparable. The impact of radiologist experience on the MRI score should be further investigated, however suggests additional educational efforts may be beneficial.\u003c/p\u003e\n\u003cp\u003eSearch failure could be another cause of errors. Undercalling errors can take place when RSE lesions are found in unexpected locations depending on uterine positioning or postoperative changes. Overcall errors are often attributable to pseudo-lesions, such as artifacts, bowel wall thickening, or peritoneal reflection thickening that may mimic RSE lesions.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe present study has several limitations. First, this was a retrospective, single-institutional study. The retrospective study design was mandatory given that a prospective study would impact the choice of surgery and potentially bias the results. External validation is necessary to assess the feasibility of our MRI score with different MRI protocols and patient preparations (25). At our institution, all MRIs are performed on a 3.0 Tesla scanner and are protocolled with vaginal gel and subcutaneous glucagon injection and without rectal gel. While some outside centers administer rectal gel to improve visualization of RSE lesions (26), this is not protocol at our institution as it may overdistend the rectum, obliterate the posterior cul-de-sac, and be associated with problematic artifacts. Furthermore, we did not have pathological confirmation for control cases who appropriately did not undergo RSE surgery due to negative rectosigmoid assessment by the surgeon at the time of endometriosis surgery. Future directions include investigating if the MRI score is applicable to lesions above the rectosigmoid colon.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn conclusion, our MRI scoring system for rectosigmoid endometriosis is a concise and qualitative scale based on suspected depth of bowel wall invasion and correlates with pathologic depth of invasion. This alignment allows the MRI scoring system to serve as a valuable guide for optimizing operative planning. \u0026nbsp;\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eRSE\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Rectosigmoid endometriosis\u003c/p\u003e\n\u003cp\u003eAUC\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Area under the curve\u003c/p\u003e\n\u003cp\u003eMP \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Muscularis propria\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eW.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.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe 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.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eGerges 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.\u003c/li\u003e\n\u003cli\u003eRousset 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.\u003c/li\u003e\n\u003cli\u003eRousset 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.\u003c/li\u003e\n\u003cli\u003eJaramillo-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.\u003c/li\u003e\n\u003cli\u003eJha 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.\u003c/li\u003e\n\u003cli\u003eSloss 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.\u003c/li\u003e\n\u003cli\u003eNezhat 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.\u003c/li\u003e\n\u003cli\u003eInternational 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.\u003c/li\u003e\n\u003cli\u003eQuintairos 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.\u003c/li\u003e\n\u003cli\u003eBurkett 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.\u003c/li\u003e\n\u003cli\u003eKeckstein 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.\u003c/li\u003e\n\u003cli\u003eMontanari 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.\u003c/li\u003e\n\u003cli\u003eThomassin-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.\u003c/li\u003e\n\u003cli\u003eVarela C, Zulfiqar M, Schiappacasse G, Menias CO. \u0026apos;Fortune cookie sign\u0026apos;: a variant of mushroom cap sign on T2 weighted MRI for deep sigmoid endometriosis. Abdom Radiol (NY). 2021;46(3):1272-5.\u003c/li\u003e\n\u003cli\u003eHarma 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.\u003c/li\u003e\n\u003cli\u003eYoon JH, Choi D, Jang KT, Kim CK, Kim H, Lee SJ, et al. Deep rectosigmoid endometriosis: \u0026quot;mushroom cap\u0026quot; sign on T2-weighted MR imaging. Abdom Imaging. 2010;35(6):726-31.\u003c/li\u003e\n\u003cli\u003eScardapane 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.\u003c/li\u003e\n\u003cli\u003eBrusic 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.\u003c/li\u003e\n\u003cli\u003eVanBuren 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.\u003c/li\u003e\n\u003cli\u003eVlek 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.\u003c/li\u003e\n\u003cli\u003eBusard 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.\u003c/li\u003e\n\u003cli\u003eHorvat 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.\u003c/li\u003e\n\u003cli\u003eChamie LP. Ultrasound evaluation of deeply infiltrative endometriosis: technique and interpretation. Abdom Radiol (NY). 2020;45(6):1648-58.\u003c/li\u003e\n\u003cli\u003eTong 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.\u003c/li\u003e\n\u003cli\u003eWild 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.\u003c/li\u003e\n\u003cli\u003eLoubeyre 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.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1. MRI Protocol for Endometriosis\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eSequence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 208px;\"\u003e\n \u003cp\u003ePlane\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 175px;\"\u003e\n \u003cp\u003eThickness (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 232px;\"\u003e\n \u003cp\u003eComments\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eT2WI TSE without fat suppression\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 208px;\"\u003e\n \u003cp\u003eAxial, sagittal and coronal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 175px;\"\u003e\n \u003cp\u003e3-5 mm (axial), 4 mm (sagittal and coronal)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 232px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eT1WI in-phase and out-of-phase GRE or Dixon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 208px;\"\u003e\n \u003cp\u003eAxial\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 175px;\"\u003e\n \u003cp\u003e5 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 232px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eT1WI with fat suppression without intravenous contrast material\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 208px;\"\u003e\n \u003cp\u003eAxial and sagittal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 175px;\"\u003e\n \u003cp\u003e3 mm (axial), 3-4 mm (sagittal)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 232px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eT1WI with intravenous contrast material\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 208px;\"\u003e\n \u003cp\u003eAxial and sagittal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 175px;\"\u003e\n \u003cp\u003e3 mm (axial), 3-4 mm (sagittal)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 232px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eDiffusion-weighted imaging\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 208px;\"\u003e\n \u003cp\u003eAxial\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 175px;\"\u003e\n \u003cp\u003e4-5 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 232px;\"\u003e\n \u003cp\u003eb value = 0, 50, 1000 sec/mm\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eT2WI fast spine echo with fat saturation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 208px;\"\u003e\n \u003cp\u003eAxial\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 175px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 232px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 216px;\"\u003e\n \u003cp\u003eT2WI echo-planar fast spine echo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 208px;\"\u003e\n \u003cp\u003eAxial\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 175px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 232px;\"\u003e\n \u003cp\u003eLarge FOV to include kidneys\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eFOV: field of view, GRE: gradient echo, T1WI: T1 weighted imaging, T2WI: T2 weighted imaging\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2. Patient and Lesion Characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 372px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 174px;\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 186px;\"\u003e\n \u003cp\u003eCase (w/ RSE surgery)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eControl (w/o RSE surgery)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 372px;\"\u003e\n \u003cp\u003ePatient number\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 174px;\"\u003e\n \u003cp\u003e95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 186px;\"\u003e\n \u003cp\u003e77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 372px;\"\u003e\n \u003cp\u003eAge [years]\u0026nbsp;\u0026dagger;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 174px;\"\u003e\n \u003cp\u003e36 (20 to 54)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 186px;\"\u003e\n \u003cp\u003e37 (22 to 54)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003e32 (20 to 44)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 372px;\"\u003e\n \u003cp\u003eInterval between MRI and endometriosis surgery [days]\u0026nbsp;\u0026dagger;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 174px;\"\u003e\n \u003cp\u003e75 (6 to 177)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 186px;\"\u003e\n \u003cp\u003e76 (6 to 177)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003e72 (10 to 162)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 372px;\"\u003e\n \u003cp\u003eMRI score (reference) [number]\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; MRI score 0\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; MRI score 1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; MRI score 2\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; MRI score 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 174px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 186px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 372px;\"\u003e\n \u003cp\u003eTypes of surgery [number]\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;Segmental resection \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n \u003cul\u003e\n \u003cli\u003eLow anterior resection\u003c/li\u003e\n \u003cli\u003eSigmoidectomy\u003c/li\u003e\n \u003c/ul\u003e\n \u003cp\u003e\u0026nbsp; Full thickness discoid resection\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; Partial thickness discoid resection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 174px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e41\u003c/p\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 186px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e41\u003c/p\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eN/A\u003c/p\u003e\n \u003cp\u003eN/A\u003c/p\u003e\n \u003cp\u003eN/A\u003c/p\u003e\n \u003cp\u003eN/A\u003c/p\u003e\n \u003cp\u003eN/A\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 372px;\"\u003e\n \u003cp\u003eDepth of invasion (for patients who underwent segmental resection or full thickness discoid resection only) [number]\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; Submucosa/mucosa\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; Muscularis propria\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; Serosa\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; No involvement\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 174px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 186px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eN/A\u003c/p\u003e\n \u003cp\u003eN/A\u003c/p\u003e\n \u003cp\u003eN/A\u003c/p\u003e\n \u003cp\u003eN/A\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026dagger;median (minimum to maximum)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3. Comparison of MRI Scores Between the Reader Study and the Reference Score in the Per-patient Reader study \u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ctable style=\"border-collapse: collapse;border: none;width: 1026px;\" class=\"fr-table-selection-hover\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 148.35pt;border: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.85pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003eReference score\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163.25pt;border-top: 1pt solid windowtext;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-image: initial;border-left: none;padding: 0in 5.4pt;height: 28.85pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003eMRI score 0\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 170.65pt;border-top: 1pt solid windowtext;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-image: initial;border-left: none;padding: 0in 5.4pt;height: 28.85pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003eMRI score 1\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 147.35pt;border-top: 1pt solid windowtext;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-image: initial;border-left: none;padding: 0in 5.4pt;height: 28.85pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003eMRI score 2\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 139.8pt;border-top: 1pt solid windowtext;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-image: initial;border-left: none;padding: 0in 5.4pt;height: 28.85pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003eMRI score 3\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\" style=\"width: 769.4pt;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-left: 1pt solid windowtext;border-image: initial;border-top: none;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003eReader 1\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 148.35pt;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-left: 1pt solid windowtext;border-image: initial;border-top: none;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e\u0026nbsp;MRI score 0\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163.25pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e5\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 170.65pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e2\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 147.35pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;background: rgb(222, 234, 246);padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e1\u003c/span\u003e\u003cspan style='font-size:15px;line-height:200%;font-family:\"MS Mincho\";color:black;'\u003e\u0026dagger;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 139.8pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;background: rgb(222, 234, 246);padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e1\u003c/span\u003e\u003cspan style='font-size:15px;line-height:200%;font-family:\"MS Mincho\";color:black;'\u003e\u0026dagger;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 148.35pt;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-left: 1pt solid windowtext;border-image: initial;border-top: none;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e\u0026nbsp;MRI score 1\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163.25pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e11\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 170.65pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e7\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 147.35pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e5\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 139.8pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;background: rgb(222, 234, 246);padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e1\u003c/span\u003e\u003cspan style='font-size:15px;line-height:200%;font-family:\"MS Mincho\";color:black;'\u003e\u0026dagger;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 148.35pt;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-left: 1pt solid windowtext;border-image: initial;border-top: none;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e\u0026nbsp;MRI score 2\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163.25pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;background: rgb(251, 228, 213);padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e0 \u003cstrong\u003e*\u003c/strong\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 170.65pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e4\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 147.35pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e13\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 139.8pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e6\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 148.35pt;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-left: 1pt solid windowtext;border-image: initial;border-top: none;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e\u0026nbsp;MRI score 3\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163.25pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;background: rgb(251, 228, 213);padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e0 \u003cstrong\u003e*\u003c/strong\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 170.65pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;background: rgb(251, 228, 213);padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e1 \u003cstrong\u003e*\u003c/strong\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 147.35pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e11\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 139.8pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.1pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e27\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\" style=\"width: 769.4pt;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-left: 1pt solid windowtext;border-image: initial;border-top: none;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003eReader 2\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 148.35pt;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-left: 1pt solid windowtext;border-image: initial;border-top: none;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e\u0026nbsp;MRI score 0\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163.25pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e7\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 170.65pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e1\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 147.35pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;background: rgb(222, 234, 246);padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e0\u003c/span\u003e\u003cspan style='font-size:15px;line-height:200%;font-family:\"MS Mincho\";color:black;'\u003e\u0026dagger;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 139.8pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;background: rgb(222, 234, 246);padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e0\u003c/span\u003e\u003cspan style='font-size:15px;line-height:200%;font-family:\"MS Mincho\";color:black;'\u003e\u0026dagger;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 148.35pt;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-left: 1pt solid windowtext;border-image: initial;border-top: none;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e\u0026nbsp;MRI score 1\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163.25pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e8\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 170.65pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e7\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 147.35pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e5\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 139.8pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;background: rgb(222, 234, 246);padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e0\u003c/span\u003e\u003cspan style='font-size:15px;line-height:200%;font-family:\"MS Mincho\";color:black;'\u003e\u0026dagger;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 148.35pt;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-left: 1pt solid windowtext;border-image: initial;border-top: none;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e\u0026nbsp;MRI score 2\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163.25pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;background: rgb(251, 228, 213);padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e1 \u003cstrong\u003e*\u003c/strong\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 170.65pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e6\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 147.35pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e13\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 139.8pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e3\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 148.35pt;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-left: 1pt solid windowtext;border-image: initial;border-top: none;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e\u0026nbsp;MRI score 3\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 163.25pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;background: rgb(251, 228, 213);padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e0 \u003cstrong\u003e*\u003c/strong\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 170.65pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;background: rgb(251, 228, 213);padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e0 \u003cstrong\u003e*\u003c/strong\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 147.35pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e12\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 139.8pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;vertical-align: top;\"\u003e\n \u003cp style='margin:0in;line-height:200%;font-size:14px;font-family:\"Century\",serif;'\u003e\u003cspan style='font-size:15px;line-height:200%;font-family: \"Arial\",sans-serif;color:black;'\u003e32\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026dagger;Under-call case: the cases with reader\u0026rsquo;s score 2 or more lower than the reference score. \u003cstrong\u003e*\u0026nbsp;\u003c/strong\u003eOver-call cases: the cases with reader\u0026rsquo;s score 2 or more higher than the reference score.\u0026nbsp;\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eTable 4. Quantitative Parameters Measured by Three Readers in the Per-lesion Reader study\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" class=\"fr-table-selection-hover\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 324px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 138px;\"\u003e\n \u003cp\u003eReader X\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 154px;\"\u003e\n \u003cp\u003eReader Y\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 134px;\"\u003e\n \u003cp\u003eReader Z\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003eInterreader agreement**\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 324px;\"\u003e\n \u003cp\u003eLength (mm)\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;Reference MRI score 1\u0026dagger;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;Reference MRI score 2\u0026dagger;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;Reference MRI score 3\u0026dagger;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;P value \u0026ndash; difference among MRI scores*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e4.5 (0-7)\u003c/p\u003e\n \u003cp\u003e10 (2-50)\u003c/p\u003e\n \u003cp\u003e31 (3-66)\u003c/p\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 154px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0 (0-33)\u003c/p\u003e\n \u003cp\u003e21 (0-78)\u003c/p\u003e\n \u003cp\u003e30 (0-72)\u003c/p\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 134px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e10.5 (4-33)\u003c/p\u003e\n \u003cp\u003e25.5 (6-100)\u003c/p\u003e\n \u003cp\u003e41 (11-72)\u003c/p\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003e0.59\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 324px;\"\u003e\n \u003cp\u003eTransverse (mm)\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;Reference MRI score 1\u0026dagger;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;Reference MRI score 2\u0026dagger;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;Reference MRI score 3\u0026dagger;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;P value \u0026ndash; difference among MRI scores*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e3 (0-9)\u003c/p\u003e\n \u003cp\u003e11 (3-27)\u003c/p\u003e\n \u003cp\u003e18 (5-31)\u003c/p\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 154px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0 (0-13)\u003c/p\u003e\n \u003cp\u003e7 (0-25)\u003c/p\u003e\n \u003cp\u003e12 (0-29)\u003c/p\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 134px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e8.5 (4-27)\u003c/p\u003e\n \u003cp\u003e13.5 (5-40)\u003c/p\u003e\n \u003cp\u003e22 (8-46)\u003c/p\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003e0.42\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 324px;\"\u003e\n \u003cp\u003eThickness (mm)\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;Reference MRI score 1\u0026dagger;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;Reference MRI score 2\u0026dagger;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;Reference MRI score 3\u0026dagger;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;P value \u0026ndash; difference among MRI scores*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 138px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0 (0-11)\u003c/p\u003e\n \u003cp\u003e8 (3-21)\u003c/p\u003e\n \u003cp\u003e14 (5-29)\u003c/p\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 154px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0(0-12)\u003c/p\u003e\n \u003cp\u003e4 (0-19)\u003c/p\u003e\n \u003cp\u003e11 (0-17)\u003c/p\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 134px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e8 (4-22)\u003c/p\u003e\n \u003cp\u003e15 (6-64)\u003c/p\u003e\n \u003cp\u003e25 (11-49)\u003c/p\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 198px;\"\u003e\n \u003cp\u003e0.31\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026dagger;median (minimum to maximum). * The differences of values among MRI scores 1, 2, and 3 were assessed by one-way Analysis of Variance. P\u0026lt;0.05 was considered statistically significant. ** Interreader agreement was assessed by intraclass correlation.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"abdominal-radiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"aima","sideBox":"Learn more about [Abdominal Radiology](http://link.springer.com/journal/261)","snPcode":"261","submissionUrl":"https://submission.springernature.com/new-submission/261/3","title":"Abdominal Radiology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-6336241/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6336241/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e 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.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePurpose:\u003c/strong\u003e 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.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterial and Methods:\u003c/strong\u003e 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.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e 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.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOur MRI scoring system based on suspected depth of bowel invasion showed good diagnostic performance to predict the type of surgical intervention needed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSummary Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis novel MRI scoring system for rectosigmoid endometriosis is a concise and qualitative scale based on suspected depth of bowel wall invasion to best guide operative planning.\u003c/p\u003e","manuscriptTitle":"Proposed New MRI Scoring System of Rectosigmoid Endometriosis to Guide Operative Planning","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-05 06:27:40","doi":"10.21203/rs.3.rs-6336241/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-05-09T12:07:52+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-23T16:15:02+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"192191928690364853945726507972399081449","date":"2025-04-14T13:34:27+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-04-04T01:10:13+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-04-03T12:34:10+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-03T11:12:15+00:00","index":"","fulltext":""},{"type":"submitted","content":"Abdominal Radiology","date":"2025-03-30T00:52:52+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"abdominal-radiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"aima","sideBox":"Learn more about [Abdominal Radiology](http://link.springer.com/journal/261)","snPcode":"261","submissionUrl":"https://submission.springernature.com/new-submission/261/3","title":"Abdominal Radiology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"19da35a6-0796-4fee-b875-59883ed85eb3","owner":[],"postedDate":"May 5th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-06-02T16:07:26+00:00","versionOfRecord":{"articleIdentity":"rs-6336241","link":"https://doi.org/10.1007/s00261-025-05021-8","journal":{"identity":"abdominal-radiology","isVorOnly":false,"title":"Abdominal Radiology"},"publishedOn":"2025-05-29 15:57:22","publishedOnDateReadable":"May 29th, 2025"},"versionCreatedAt":"2025-05-05 06:27:40","video":"","vorDoi":"10.1007/s00261-025-05021-8","vorDoiUrl":"https://doi.org/10.1007/s00261-025-05021-8","workflowStages":[]},"version":"v1","identity":"rs-6336241","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6336241","identity":"rs-6336241","version":["v1"]},"buildId":"WvIrzKhiLBfengagbw6Ux","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}