Analysis of the Diagnostic Performance of a Simplified Rectal Magnetic Resonance Imaging Protocol in the Evaluation of Rectal Cancer

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Materials and Methods: This retrospective study included patients with newly diagnosed rectal cancer confirmed by pathology who underwent standard rectal MRI scanning. The simplified rectal MRI scanning protocol consisted of the first three sequences of the standard protocol： pelvic sagittal fat-suppressed T2-weighted imaging (T2WI), oblique axial T2WI, and diffusion-weighted imaging (DWI). Four radiologists independently reviewed the images from the simplified and standard rectal MRI scans to assess image quality and observe the primary tumor, extramural invasion, and lymph node metastasis of rectal cancer. Results : A total of 359 patients (198 males and 161 females; mean age = 62.2 ± 6.5 years) were included. 192 patients had extramural invasion, and 146 patients had regional or distant lymph node metastasis. The image quality of the simplified protocol was rated as good or better in 88.3% of cases, which was significantly higher than that of the standard protocol. The T-staging accuracy of the simplified protocol was 97.77%; the sensitivity and specificity for assessing extramural invasion were 97.42% and 92.61%, respectively; and the sensitivity and specificity for detecting lymph node metastasis were 76.47% and 84.20%, respectively. The T-staging accuracy of the standard protocol was 98.89%; the sensitivity and specificity for assessing extramural invasion were 97.39% and 93.64%, respectively; and the sensitivity and specificity for detecting lymph node metastasis were 78.44% and 86.29%, respectively. No statistically significant differences were observed between the two protocols. Conclusion : The simplified rectal MRI scanning protocol demonstrated comparable accuracy in T-staging, as well as sensitivity and specificity in the evaluation of extramural invasion and lymph node metastasis, to the standard rectal MRI scanning protocol. Moreover, the image quality of the simplified protocol is superior to that of the standard protocol. Therefore, the simplified rectal MRI scanning protocol can be used as an alternative to the standard rectal MRI scanning protocol in clinical practice. Rectal cancer Magnetic resonance imaging Simplified MRI scanning Diffusion-weighted MRI Introduction Magnetic Resonance Imaging (MRI) is one of the most important tools for the assessment and follow-up of patients with rectal cancer [1, 2, 3] . A study found that among patients with rectal cancer, the median follow-up time was 5.0 years, with a local recurrence rate of 31% and an overall survival rate of 85% [4, 5, 6] . Patients require multiple MRI assessments both before treatment and within 2 to 5 years after treatment. However, the current MRI scanning protocols are time-consuming, and most patients with rectal cancer are elderly and frail, often unable to tolerate long-duration MRI examinations. Statistical studies have shown that only a minority of patients with rectal cancer undergo MRI examinations [7-9] . We propose a simplified rectal MRI scanning protocol that significantly reduces scanning time and improves patient comfort. The purpose of this study is to compare the diagnostic performance of the simplified rectal MRI scanning protocol with the standard rectal MRI scanning protocol, to validate the feasibility of the simplified protocol, and to provide a reference for clinical decision-making. 1 Materials and Methods 1.1 General Information: Patient information was retrieved from the Radiology Information System (RIS) and Picture Archiving and Communication System (PACS) databases of our hospital, with the search covering the period from January 2023 to January 2025. Patients who underwent rectal MRI examinations were identified. The inclusion criteria were as follows: patients with clinical suspicion of rectal cancer who were undergoing their first rectal MRI examination; all cases were confirmed as rectal cancer by pathology. The exclusion criteria were as follows: presence of severe motion artifacts or metal artifacts, poor image quality, and consensus among radiologists that the images would affect the diagnostic outcome. 1.2 MRI Examination Protocols: The standard rectal MRI protocol for rectal cancer patients at our hospital includes the following sequences: sagittal fat-suppressed T2-weighted imaging (T2WI), oblique axial T2WI, oblique axial diffusion-weighted imaging (DWI) sequence, oblique axial fat-suppressed T2WI, oblique axial T1WI or T1WI with in-phase and opposed-phase sequences, coronal fat-suppressed T2WI, and dynamic contrast-enhanced scans in three planes. The MRI scans were performed using a Philips Elition 3T MRI scanner (Philips Healthcare, Netherlands). The scanning parameters for the standard rectal MRI protocol are as follows:（1）、 Sagittal fat-suppressed T2WI: TSE sequence, TR = 2500 ms, TE = 70 ms, FA = 90°, FOV = 24 cm × 24 cm, matrix = 240 × 240, slice thickness = 3 mm, slice gap = 0.3 mm.（2） Oblique axial T2WI: TSE sequence, TR = 2500 ms, TE = 100 ms, FA = 90°, FOV = 20 cm × 20 cm, matrix = 320 × 240, slice thickness = 3 mm, slice gap = 0.4 mm.（3） Oblique axial diffusion-weighted sequence: EPI sequence, TR = 4500 ms, TE = 80 ms, FOV = 30 cm × 22 cm, matrix = 168 × 168, slice thickness = 3 mm, slice gap = 0.4 mm, b-values = 50, 800 mm²/s.（4） Oblique axial fat-suppressed T2WI: TSE-SPAIR sequence, TR = 4500 ms, TE = 100 ms, FA = 90°, FOV = 20 cm × 20 cm, matrix = 320 × 240, slice thickness = 3 mm, slice gap = 0.4 mm.（5） Oblique axial T1WI: TSE sequence, TR = 550 ms, TE = 10 ms, FA = 90°, FOV = 20 cm × 20 cm, matrix = 320 × 240, slice thickness = 3 mm, slice gap = 0.4 mm.（6） Oblique coronal T2WI: TSE sequence, TR = 2500 ms, TE = 100 ms, FA = 90°, FOV = 24 cm × 24 cm, matrix = 240 × 240, slice thickness = 3 mm, slice gap = 0.3 mm.（7） Contrast-enhanced scan: mDIXON sequence, including oblique axial, oblique coronal, and sagittal planes, TR = 5 ms, TE = 0, FA = 90°, slice thickness = 3 mm, slice gap = 0.4 mm; contrast agent injection rate = 2 ml/s, dose = 0.1 mmol/kg.The simplified rectal MRI scanning protocol includes only the first three sequences of the standard protocol: pelvic sagittal fat-suppressed T2WI, oblique axial T2WI, and oblique axial DWI (b-values = 0 and 1000), with the generation of apparent diffusion coefficient (ADC) maps. This protocol does not include the contrast-enhanced scanning sequences. A comparison of the sequences between the two protocols is shown in Table 1. Table 1: Comparison of Sequences and Scan Duration Between the Two Scanning Protocols Sequence/Scan Duration Sagittal Fat-Suppressed T2WI Oblique Axial T2WI Oblique Axial DWI Sequence Oblique Axial Fat-Suppressed T2WI Oblique Axial T1WI Oblique Coronal T2WI Contrast-Enhanced Scan Total Scan Time Standard Protocol Yes Yes Yes Yes Yes Yes Optional 30-40 minutes Simplified Protocol Yes Yes Yes 15-20 minutes 1.3 Image Interpretation: The acquired images were divided into two groups: the simplified protocol group and the standard protocol group. Four radiologists independently assessed the images in both groups, with two radiologists assigned to each group. All four radiologists were associate chief physicians with over 10 years of experience in their field. Prior to independent image interpretation, the radiologists were unaware of the final pathological results of the patients and were not informed that the simplified protocol was derived from the standard protocol. The interpretation content included: (1) evaluation of image quality; (2) characteristics of the primary rectal cancer lesion, including tumor morphology, size, and location; for mass-forming tumors, the maximum diameter was recorded; for infiltrating tumors, the extent of circumferential involvement was recorded; (3) assessment of perirectal invasion, including: involvement of the mesorectal fascia (Mesorectal Fascia, MRF); extramural vascular invasion (Extramural Vascular Invasion, EMVI); involvement of the peritoneal reflection, surrounding organs, and pelvic wall; and pelvic metastasis; (4) evaluation of regional and distant lymph node metastasis, with regional lymph nodes including those within the mesorectum, around the superior rectal artery, and around the internal iliac artery; and distant lymph nodes including those around the external iliac artery and inguinal lymph nodes. The final interpretation conclusions were categorized into five scenarios: positive, probably positive, indeterminate, probably negative, and negative. For patients whose imaging results were interpreted as positive, probably positive, or indeterminate, a final diagnosis of positivity was considered a true positive, while a final diagnosis of negativity was considered a false positive. For patients whose imaging results were interpreted as negative, a final diagnosis of negativity was considered a true negative, while a final diagnosis of positivity was considered a false negative. 1.4 Data Analysis: The interpretation results of the two groups of images were compared with the pathological findings to calculate the sensitivity and specificity of each group. The Fleiss Kappa statistic was used to assess the consistency between the two radiologists in each group when evaluating the imaging results. The Generalized Estimated Equation (GEE) was employed to compare the sensitivity and specificity of the two protocols. The “Figure of Merit” (FOM) was calculated to evaluate the lesion detection capability. The McNemar test was used to determine whether there were statistically significant differences between the two protocols, with a p-value less than 0.05 indicating a statistically significant difference. 2 Results A total of 359 patients (198 males and 161 females; mean age = 65.2 ± 6.5 years) were included in this study, all of whom were confirmed by pathology. Among them, 192 patients had extramural invasion, and 146 patients had regional or distant lymph node metastasis. The basic characteristics of the patients are shown in Table 2. Table 2: Basic Patient Information Primary Tumor n=359 T1-2 119 T3 158 T4 82 Extramural Invasion n=192 MRF 142 EMVI 166 Invasion of surrounding organs or pelvic wall 82 Pelvic metastasis 35 Lymph Node Metastasis n=146 Regional lymph node metastasis 146 Distant lymph node metastasis 91 Image Quality Assessment Results: In the simplified protocol group, 317 patients (88.3%) had image quality rated as good or better.In the standard protocol group, 285 patients (79.4%) had image quality rated as good or better.The difference between the two groups was statistically significant (chi-square value = 10.484, p < 0.001). Patient Demographics: The majority of patients in this study were over 60 years old, accounting for 91.5% of the cohort.Males accounted for 55.2% of the patients, slightly higher than females, which is consistent with the epidemiological studies of rectal cancer [5, 6] .The most common T stage in this cohort was T3, accounting for 44% of the cases.There were 82 cases of T4 stage, which showed invasion of surrounding organs or pelvic wall on MRI.Some patients with T3 and T4 stages also had pelvic metastasis.Lymph node metastasis was present in 146 patients. Diagnostic Performance: The accuracy of T staging for the simplified protocol was 97.77%, and for the standard protocol, it was 98.89%. The difference between the two protocols was not statistically significant.For assessing extramural invasion:Sensitivity and specificity of the simplified protocol were 97.42% and 92.61%, respectively.Sensitivity and specificity of the standard protocol were 97.39% and 93.64%, respectively.The differences in sensitivity and specificity between the two protocols were not statistically significant.For detecting lymph node metastasis:Sensitivity and specificity of the simplified protocol were 76.47% and 84.20%, respectively.Sensitivity and specificity of the standard protocol were 78.44% and 86.29%, respectively.Both protocols had relatively lower sensitivity and specificity for detecting lymph node metastasis, and the differences between the two protocols were not statistically significant. Comparison of the Diagnostic Performance of the Two Scanning Protocols is shown in Tables 3 and 4. T able 3: Comparison of T Staging Accuracy between Simplified and Standard Protocols Simplified Protocol Standard Protocol Pathology T1-2 112 115 119 T3 166 161 158 T4 81 83 82 Accuracy 97.77% 98.89% Note : Using the z-test, the difference in diagnostic accuracy between the simplified and standard protocols was not statistically significant (t-value = -1.25, p-value = 0.211, greater than 0.05). Table 4: Comparison of Diagnostic Performance between Simplified Scheme and Standard Scheme Diagnostic Category Parameter Simplified Protocol Standard Protocol Pathology Chi-square Value P-value Extramural Invasion Positive 179 181 192 False Positive 13 11 Negative 163 162 167 False Negative 4 5 Sensitivity (95% CI) 97.42% 97.39% 0.018 0.895 （90.49%，100%） （90.41%，100%） Specificity (95% CI) 92.61% 93.64% 0.51 0.475 （88.98%，96.24%） （89.99%，97.29%） Lymph Node Metastasis Positive 113 117 146 False Positive 33 29 Negative 178 181 213 False Negative 35 32 Sensitivity (95% CI) 76.47% 78.44% 0.0113 0.916 （68.45% - 84.49%） （71.32% - 85.56%） Specificity (95% CI) 84.20% 86.29% 0.3117 0.576 （78.37% - 89.93%） （80.42% - 92.16%） Note: Confidence Interval (CI) refers to the confidence interval; the data are derived from the retrospective analysis of this study, with statistical methods including Generalized Estimating Equation (GEE) and McNemar test. The interobserver agreement of the simplified rectal MRI scanning protocol is comparable to that of the standard protocol, especially in the T staging of rectal cancer (using Fleiss Kappa statistics, the Kappa coefficients are: simplified rectal MRI scanning protocol = 0.79, standard protocol = 0.81). 3 Discussion The standard rectal MRI scanning protocol encompasses a variety of sequences, including sagittal fat-suppressed T2WI, oblique axial T2WI, oblique axial DWI sequence, oblique axial fat-suppressed T2WI, oblique axial T1WI or T1WI with in-phase and opposed-phase sequences, and coronal fat-suppressed T2WI [10,11] . In addition, dynamic contrast-enhanced scans are commonly performed in most hospitals, extending the total scanning time to approximately 30-40 minutes. This lengthy scanning process poses significant challenges, especially for elderly patients who make up the majority of rectal cancer cases (in this study, 91.5% of patients were over 60 years old) and often have weaker physical conditions. As a result, many patients are unable to tolerate long-duration MRI examinations, leading to low acceptance rates of MRI scans and difficulties in clinical implementation. In our hospital, the preoperative rectal MRI examination rate for rectal cancer inpatients is less than 60%, which is far from the 100% target recommended by the 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) guidelines [12] . In this study, the standard protocol exhibited a relatively low proportion of good or better image quality (79.4%). This finding aligns with a previous study, which reported that with the standard rectal MRI scanning protocol, the proportion of good or better image quality was approximately 72%-82% [13] . In stark contrast, the simplified protocol achieved a significantly higher proportion of good or better image quality (88.3%), with a statistically significant difference compared to the standard protocol. The study found that in the additional scans following the simplified protocol, patient motion artifacts were significantly increased, which led to a marked reduction in the overall image quality assessment of the standard protocol. This indicates that the simplified protocol, with its shorter scanning time, significantly improves patient tolerance and is more suitable for clinical application. Multiple studies have identified DWI and T2WI as the core sequences in the standard rectal MRI scanning protocol, with DWI significantly outperforming T2WI and contrast-enhanced T1WI in rectal cancer staging and lymph node assessment [10,11] . In the evaluation of mucinous tumors, although some studies suggest that contrast-enhanced sequences may have advantages [14] , the simplified protocol in this study did not significantly reduce diagnostic specificity. This may be attributed to the high sensitivity and specificity of DWI combined with ADC value measurements for diagnosing mucinous tumors. Additionally, this study found that T2WI can assess EMVI by observing the morphology of the extramural vascular root and the disappearance of vascular flow voids, which differs from the findings of Volovat et al. [14-17] , who argued that contrast-enhanced T1WI has higher sensitivity and specificity in EMVI assessment. This finding further confirms the applicability and reliability of the simplified protocol across different pathological types. This study retrospectively analyzed 359 patients with pathologically confirmed rectal cancer, comparing the diagnostic performance of the simplified rectal MRI protocol with the standard protocol. The results showed that the simplified protocol achieved comparable accuracy in T staging, sensitivity, and specificity in assessing extramural invasion and detecting lymph node metastasis to the standard protocol (P>0.05). This indicates that by streamlining the scanning sequences (retaining only pelvic sagittal fat-suppressed T2WI, oblique axial T2WI, and DWI), equivalent diagnostic performance can still be maintained. Some hospitals routinely perform additional contrast-enhanced scans, which not only increase the examination time and cost for patients but also pose potential risks associated with contrast agents, such as allergic reactions and nephrotoxicity [18] . The simplified protocol, with its significantly shorter scanning time and no need for contrast agents, avoids these risks. This is particularly clinically significant for elderly and frail patients, especially those with rectal cancer requiring multiple follow-ups. Despite the positive results of this study, there are some limitations. First, multicenter prospective studies with homogeneous patient populations are needed to reduce bias in the study results. Second, further investigation into the application of the simplified MRI protocol in different types of rectal cancer patients, such as those with different stages and treatment plans, is warranted. Additionally, considering the advantages of the simplified MRI protocol in detecting small lesions, future research could explore its potential for early rectal cancer screening. Finally, with the development of artificial intelligence and deep learning technologies [16,17,19] , future studies could integrate these advanced techniques to further enhance the diagnostic efficacy and accuracy of the simplified MRI protocol. Conclusion The simplified rectal MRI scanning protocol provides diagnostic performance equivalent to the standard protocol. Its high sensitivity and specificity help optimize the MRI examination process, reducing patient waiting and scanning times, improving patient comfort, and significantly enhancing MRI image quality by reducing motion artifacts. The simplified protocol offers an efficient and cost-effective alternative for rectal cancer assessment. Abbreviations MRI: Magnetic resonance imaging RIS：Radiology Information System PACS：Picture Archiving and Communication System T2WI：T2-weighted imaging DWI：diffusion-weighted imaging ADC：apparent diffusion coefficient MRF：Mesorectal Fascia EMVI：Extramural Vascular Invasion Declarations Acknowledgements Data for this study come from Heze Hospital of Shandong Provincial Hospital (Heze Municipal Hospital). Author contributions Xiaoxin Zhao collected the cases, processed the data, and drafted and revised the manuscript. Hongzhou Ma proposed the research idea and provided important guidance for this study. All authors helped to write and edit the manuscript, and approved the final version. Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Data availability The authors declare that all data supporting the fundings of this study are available within the paper and its source data for the figures and tables in this study are available from the corresponding authors upon request. Ethical approval and consent to participate This research adhered to the Declaration of Helsinki and received ethical clearance from the Shandong Provincial Hospital Affiliated Heze Hospital Ethics Committee, waiving participant informed consent requirements under approval code 2025L013. Human Ethics and Consent to Participate declarations: not applicable. Consent for publication Not applicable for this paper. 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Dis Colon Rectum, 2024, 67(12): 1528-1535. DOI: 10.1097/DCR.0000814379.37407.46. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-7079111","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":497419102,"identity":"5c6a7679-b43f-4d81-8493-11632914253f","order_by":0,"name":"Zhao Xiaoxin","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA00lEQVRIiWNgGAWjYBACNv7mgw8+8PyXsz/ffIA4LXwSx5INZ8gwGzPcOJZAnBY5hhwzaQ4b5sSGAzkGRDqM4YCBNEMOmzFjw5mPN94w2MnpNhDSwtyQYFxwhkeOmbl3s+UchmRjswOEbTmQPLNHwpiN4ew2aR6GA4nbCGtJbDjM+88gsYch5xmxWpIZm3l4EhJnAD1EpBaJY8yMM3gOGBtIHDO2nGNAhF/k+/u///jAc0DOgL/54Y03FXZyBLWgAAkeIqMGWQupOkbBKBgFo2BEAADd10FlcdVdUwAAAABJRU5ErkJggg==","orcid":"","institution":"Heze Hospital of Shandong Provincial Hospital (Heze Municipal Hospital)","correspondingAuthor":true,"prefix":"","firstName":"Zhao","middleName":"","lastName":"Xiaoxin","suffix":""},{"id":497419103,"identity":"d80fcddc-2e07-46c8-926c-e5a8ca00ae33","order_by":1,"name":"Ma Hongzhou","email":"","orcid":"","institution":"Heze Hospital of Shandong Provincial Hospital (Heze Municipal Hospital)","correspondingAuthor":false,"prefix":"","firstName":"Ma","middleName":"","lastName":"Hongzhou","suffix":""}],"badges":[],"createdAt":"2025-07-09 02:53:22","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7079111/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7079111/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106403579,"identity":"59dcf806-a279-4f32-9d4f-b980f67748ab","added_by":"auto","created_at":"2026-04-08 09:14:32","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":831930,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7079111/v1/a471ba77-bd17-4633-a6a9-e8ea3bdd513b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Analysis of the Diagnostic Performance of a Simplified Rectal Magnetic Resonance Imaging Protocol in the Evaluation of Rectal Cancer","fulltext":[{"header":"Introduction","content":"\u003cp\u003eMagnetic Resonance Imaging (MRI) is one of the most important tools for the assessment and follow-up of patients with rectal cancer \u003csup\u003e[1, 2, 3]\u003c/sup\u003e. A study found that among patients with rectal cancer, the median follow-up time was 5.0 years, with a local recurrence rate of 31% and an overall survival rate of 85%\u003csup\u003e\u0026nbsp;[4, 5, 6]\u003c/sup\u003e. Patients require multiple MRI assessments both before treatment and within 2 to 5 years after treatment. However, the current MRI scanning protocols are time-consuming, and most patients with rectal cancer are elderly and frail, often unable to tolerate long-duration MRI examinations. Statistical studies have shown that only a minority of patients with rectal cancer undergo MRI examinations \u003csup\u003e[7-9]\u003c/sup\u003e. We propose a simplified rectal MRI scanning protocol that significantly reduces scanning time and improves patient comfort. The purpose of this study is to compare the diagnostic performance of the simplified rectal MRI scanning protocol with the standard rectal MRI scanning protocol, to validate the feasibility of the simplified protocol, and to provide a reference for clinical decision-making.\u003c/p\u003e"},{"header":"1 Materials and Methods","content":"\u003cp\u003e\u003cstrong\u003e1.1 General Information:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatient information was retrieved from the Radiology Information System (RIS) and Picture Archiving and Communication System (PACS) databases of our hospital, with the search covering the period from January 2023 to January 2025. Patients who underwent rectal MRI examinations were identified. The inclusion criteria were as follows: patients with clinical suspicion of rectal cancer who were undergoing their first rectal MRI examination; all cases were confirmed as rectal cancer by pathology. The exclusion criteria were as follows: presence of severe motion artifacts or metal artifacts, poor image quality, and consensus among radiologists that the images would affect the diagnostic outcome.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.2 MRI Examination Protocols:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe standard rectal MRI protocol for rectal cancer patients at our hospital includes the following sequences: sagittal fat-suppressed T2-weighted imaging (T2WI), oblique axial T2WI, oblique axial diffusion-weighted imaging (DWI) sequence, oblique axial fat-suppressed T2WI, oblique axial T1WI or T1WI with in-phase and opposed-phase sequences, coronal fat-suppressed T2WI, and dynamic contrast-enhanced scans in three planes. The MRI scans were performed using a Philips Elition 3T MRI scanner (Philips Healthcare, Netherlands). The scanning parameters for the standard rectal MRI protocol are as follows:（1）、\u003cstrong\u003eSagittal fat-suppressed T2WI:\u003c/strong\u003e TSE sequence, TR = 2500 ms, TE = 70 ms, FA = 90\u0026deg;, FOV = 24 cm \u0026times; 24 cm, matrix = 240 \u0026times; 240, slice thickness = 3 mm, slice gap = 0.3 mm.（2）\u003cstrong\u003eOblique axial T2WI:\u003c/strong\u003e TSE sequence, TR = 2500 ms, TE = 100 ms, FA = 90\u0026deg;, FOV = 20 cm \u0026times; 20 cm, matrix = 320 \u0026times; 240, slice thickness = 3 mm, slice gap = 0.4 mm.（3）\u003cstrong\u003eOblique axial diffusion-weighted sequence:\u003c/strong\u003e EPI sequence, TR = 4500 ms, TE = 80 ms, FOV = 30 cm \u0026times; 22 cm, matrix = 168 \u0026times; 168, slice thickness = 3 mm, slice gap = 0.4 mm, b-values = 50, 800 mm\u0026sup2;/s.（4）\u003cstrong\u003eOblique axial fat-suppressed T2WI:\u003c/strong\u003e TSE-SPAIR sequence, TR = 4500 ms, TE = 100 ms, FA = 90\u0026deg;, FOV = 20 cm \u0026times; 20 cm, matrix = 320 \u0026times; 240, slice thickness = 3 mm, slice gap = 0.4 mm.（5）\u003cstrong\u003eOblique axial T1WI:\u003c/strong\u003e TSE sequence, TR = 550 ms, TE = 10 ms, FA = 90\u0026deg;, FOV = 20 cm \u0026times; 20 cm, matrix = 320 \u0026times; 240, slice thickness = 3 mm, slice gap = 0.4 mm.（6）\u003cstrong\u003eOblique coronal T2WI:\u003c/strong\u003e TSE sequence, TR = 2500 ms, TE = 100 ms, FA = 90\u0026deg;, FOV = 24 cm \u0026times; 24 cm, matrix = 240 \u0026times; 240, slice thickness = 3 mm, slice gap = 0.3 mm.（7）\u003cstrong\u003eContrast-enhanced scan:\u003c/strong\u003e mDIXON sequence, including oblique axial, oblique coronal, and sagittal planes, TR = 5 ms, TE = 0, FA = 90\u0026deg;, slice thickness = 3 mm, slice gap = 0.4 mm; contrast agent injection rate = 2 ml/s, dose = 0.1 mmol/kg.The simplified rectal MRI scanning protocol includes only the first three sequences of the standard protocol: pelvic sagittal fat-suppressed T2WI, oblique axial T2WI, and oblique axial DWI (b-values = 0 and 1000), with the generation of apparent diffusion coefficient (ADC) maps. This protocol does not include the contrast-enhanced scanning sequences.\u003c/p\u003e\n\u003cp\u003eA comparison of the sequences between the two protocols is shown in Table 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1: Comparison of Sequences and Scan Duration Between the Two Scanning Protocols\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"553\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 73px;\"\u003eSequence/Scan Duration\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 45px;\"\u003eSagittal Fat-Suppressed T2WI\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 15.0259%;\"\u003eOblique Axial T2WI\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 46px;\"\u003eOblique Axial DWI Sequence\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 17.7893%;\"\u003eOblique Axial Fat-Suppressed T2WI\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 50px;\"\u003eOblique Axial T1WI\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003eOblique Coronal T2WI\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003eContrast-Enhanced Scan\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 88px;\"\u003eTotal Scan Time\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003eStandard Protocol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 45px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 46px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 50px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003eOptional\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 88px;\"\u003e\n \u003cp\u003e30-40 minutes\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003eSimplified Protocol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 45px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 46px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 50px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 73px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 88px;\"\u003e\n \u003cp\u003e15-20 minutes\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e1.3 Image Interpretation:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe acquired images were divided into two groups: the simplified protocol group and the standard protocol group. Four radiologists independently assessed the images in both groups, with two radiologists assigned to each group. All four radiologists were associate chief physicians with over 10 years of experience in their field. Prior to independent image interpretation, the radiologists were unaware of the final pathological results of the patients and were not informed that the simplified protocol was derived from the standard protocol. The interpretation content included: (1) evaluation of image quality; (2) characteristics of the primary rectal cancer lesion, including tumor morphology, size, and location; for mass-forming tumors, the maximum diameter was recorded; for infiltrating tumors, the extent of circumferential involvement was recorded; (3) assessment of perirectal invasion, including: involvement of the mesorectal fascia (Mesorectal Fascia, MRF); extramural vascular invasion (Extramural Vascular Invasion, EMVI); involvement of the peritoneal reflection, surrounding organs, and pelvic wall; and pelvic metastasis; (4) evaluation of regional and distant lymph node metastasis, with regional lymph nodes including those within the mesorectum, around the superior rectal artery, and around the internal iliac artery; and distant lymph nodes including those around the external iliac artery and inguinal lymph nodes.\u003c/p\u003e\n\u003cp\u003eThe final interpretation conclusions were categorized into five scenarios: positive, probably positive, indeterminate, probably negative, and negative. For patients whose imaging results were interpreted as positive, probably positive, or indeterminate, a final diagnosis of positivity was considered a true positive, while a final diagnosis of negativity was considered a false positive. For patients whose imaging results were interpreted as negative, a final diagnosis of negativity was considered a true negative, while a final diagnosis of positivity was considered a false negative.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.4 Data Analysis:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe interpretation results of the two groups of images were compared with the pathological findings to calculate the sensitivity and specificity of each group. The Fleiss Kappa statistic was used to assess the consistency between the two radiologists in each group when evaluating the imaging results. The Generalized Estimated Equation (GEE) was employed to compare the sensitivity and specificity of the two protocols. The \u0026ldquo;Figure of Merit\u0026rdquo; (FOM) was calculated to evaluate the lesion detection capability. The McNemar test was used to determine whether there were statistically significant differences between the two protocols, with a p-value less than 0.05 indicating a statistically significant difference.\u003c/p\u003e"},{"header":"2 Results","content":"\u003cp\u003eA total of 359 patients (198 males and 161 females; mean age = 65.2 \u0026plusmn; 6.5 years) were included in this study, all of whom were confirmed by pathology. Among them, 192 patients had extramural invasion, and 146 patients had regional or distant lymph node metastasis. The basic characteristics of the patients are shown in Table 2.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"328\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" style=\"width: 328px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTable 2: Basic Patient Information\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePrimary Tumor\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003en=359\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eT1-2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e119\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eT3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e158\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eT4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e82\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eExtramural Invasion\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003en=192\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMRF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e142\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eEMVI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e166\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eInvasion of surrounding organs or pelvic wall\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e82\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003ePelvic metastasis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLymph Node Metastasis\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003en=146\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eRegional lymph node metastasis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e146\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eDistant lymph node metastasis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e91\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eImage Quality Assessment Results:\u003c/strong\u003eIn the simplified protocol group, 317 patients (88.3%) had image quality rated as good or better.In the standard protocol group, 285 patients (79.4%) had image quality rated as good or better.The difference between the two groups was statistically significant (chi-square value = 10.484, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePatient Demographics:\u003c/strong\u003eThe majority of patients in this study were over 60 years old, accounting for 91.5% of the cohort.Males accounted for 55.2% of the patients, slightly higher than females, which is consistent with the epidemiological studies of rectal cancer \u003csup\u003e[5, 6]\u003c/sup\u003e.The most common T stage in this cohort was T3, accounting for 44% of the cases.There were 82 cases of T4 stage, which showed invasion of surrounding organs or pelvic wall on MRI.Some patients with T3 and T4 stages also had pelvic metastasis.Lymph node metastasis was present in 146 patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDiagnostic Performance:\u003c/strong\u003eThe accuracy of T staging for the simplified protocol was 97.77%, and for the standard protocol, it was 98.89%. The difference between the two protocols was not statistically significant.For assessing extramural invasion:Sensitivity and specificity of the simplified protocol were 97.42% and 92.61%, respectively.Sensitivity and specificity of the standard protocol were 97.39% and 93.64%, respectively.The differences in sensitivity and specificity between the two protocols were not statistically significant.For detecting lymph node metastasis:Sensitivity and specificity of the simplified protocol were 76.47% and 84.20%, respectively.Sensitivity and specificity of the standard protocol were 78.44% and 86.29%, respectively.Both protocols had relatively lower sensitivity and specificity for detecting lymph node metastasis, and the differences between the two protocols were not statistically significant.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparison of the Diagnostic Performance of the Two Scanning Protocols is shown in Tables 3 and 4.\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"306\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" style=\"width: 306px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eT\u003c/strong\u003e\u003cstrong\u003eable 3: Comparison of T Staging Accuracy between Simplified and Standard Protocols\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSimplified Protocol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eStandard Protocol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePathology\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eT1-2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e112\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e115\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e119\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eT3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e166\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e161\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e158\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eT4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e81\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e82\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eAccuracy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e97.77%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e98.89%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eNote\u003c/strong\u003e: Using the z-test, the difference in diagnostic accuracy between the simplified and standard protocols was not statistically significant (t-value = -1.25, p-value = 0.211, greater than 0.05).\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"575\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"7\" style=\"width: 575px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTable 4: Comparison of Diagnostic Performance between Simplified Scheme and Standard Scheme\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 50px;\"\u003e\n \u003cp\u003eDiagnostic Category\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 50px;\"\u003e\n \u003cp\u003eParameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 149px;\"\u003e\n \u003cp\u003eSimplified Protocol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003eStandard Protocol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003ePathology\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eChi-square Value\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eP-value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"8\" style=\"width: 50px;\"\u003e\n \u003cp\u003eExtramural Invasion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 50px;\"\u003e\n \u003cp\u003ePositive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e179\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e181\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e192\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 50px;\"\u003e\n \u003cp\u003eFalse Positive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 50px;\"\u003e\n \u003cp\u003eNegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e163\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e162\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e167\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 50px;\"\u003e\n \u003cp\u003eFalse Negative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 50px;\"\u003e\n \u003cp\u003eSensitivity (95% CI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e97.42%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e97.39%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 56px;\"\u003e\n \u003cp\u003e0.018\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 51px;\"\u003e\n \u003cp\u003e0.895\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e（90.49%，100%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e（90.41%，100%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 50px;\"\u003e\n \u003cp\u003eSpecificity (95% CI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e92.61%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e93.64%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 56px;\"\u003e\n \u003cp\u003e0.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 51px;\"\u003e\n \u003cp\u003e0.475\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e（88.98%，96.24%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e（89.99%，97.29%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"8\" style=\"width: 50px;\"\u003e\n \u003cp\u003eLymph Node Metastasis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 50px;\"\u003e\n \u003cp\u003ePositive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e113\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e117\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e146\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 50px;\"\u003e\n \u003cp\u003eFalse Positive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 50px;\"\u003e\n \u003cp\u003eNegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e178\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e181\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e213\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 50px;\"\u003e\n \u003cp\u003eFalse Negative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 51px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 50px;\"\u003e\n \u003cp\u003eSensitivity (95% CI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e76.47%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e78.44%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 56px;\"\u003e\n \u003cp\u003e0.0113\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 51px;\"\u003e\n \u003cp\u003e0.916\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e（68.45% - 84.49%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e（71.32% - 85.56%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 50px;\"\u003e\n \u003cp\u003eSpecificity (95% CI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e84.20%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e86.29%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 56px;\"\u003e\n \u003cp\u003e0.3117\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 51px;\"\u003e\n \u003cp\u003e0.576\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 149px;\"\u003e\n \u003cp\u003e（78.37% - 89.93%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 152px;\"\u003e\n \u003cp\u003e（80.42% - 92.16%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 67px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eNote:\u003c/strong\u003e Confidence Interval (CI) refers to the confidence interval; the data are derived from the retrospective analysis of this study, with statistical methods including Generalized Estimating Equation (GEE) and McNemar test.\u003c/p\u003e\n\u003cp\u003eThe interobserver agreement of the simplified rectal MRI scanning protocol is comparable to that of the standard protocol, especially in the T staging of rectal cancer (using Fleiss Kappa statistics, the Kappa coefficients are: simplified rectal MRI scanning protocol = 0.79, standard protocol = 0.81).\u003c/p\u003e"},{"header":"3 Discussion","content":"\u003cp\u003e\u003cstrong\u003eThe standard rectal MRI scanning protocol\u003c/strong\u003e encompasses a variety of sequences, including sagittal fat-suppressed T2WI, oblique axial T2WI, oblique axial DWI sequence, oblique axial fat-suppressed T2WI, oblique axial T1WI or T1WI with in-phase and opposed-phase sequences, and coronal fat-suppressed T2WI \u003csup\u003e[10,11]\u003c/sup\u003e. In addition, dynamic contrast-enhanced scans are commonly performed in most hospitals, extending the total scanning time to approximately 30-40 minutes. This lengthy scanning process poses significant challenges, especially for elderly patients who make up the majority of rectal cancer cases (in this study, 91.5% of patients were over 60 years old) and often have weaker physical conditions. As a result, many patients are unable to tolerate long-duration MRI examinations, leading to low acceptance rates of MRI scans and difficulties in clinical implementation. In our hospital, the preoperative rectal MRI examination rate for rectal cancer inpatients is less than 60%, which is far from the 100% target recommended by the 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) guidelines\u003csup\u003e\u0026nbsp;[12]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eIn this study, the standard protocol exhibited a relatively low proportion of good or better image quality (79.4%). This finding aligns with a previous study, which reported that with the standard rectal MRI scanning protocol, the proportion of good or better image quality was approximately 72%-82% \u003csup\u003e[13]\u003c/sup\u003e. In stark contrast, the simplified protocol achieved a significantly higher proportion of good or better image quality (88.3%), with a statistically significant difference compared to the standard protocol. The study found that in the additional scans following the simplified protocol, patient motion artifacts were significantly increased, which led to a marked reduction in the overall image quality assessment of the standard protocol. This indicates that the simplified protocol, with its shorter scanning time, significantly improves patient tolerance and is more suitable for clinical application.\u003c/p\u003e\n\u003cp\u003eMultiple studies have identified DWI and T2WI as the core sequences in the standard rectal MRI scanning protocol, with DWI significantly outperforming T2WI and contrast-enhanced T1WI in rectal cancer staging and lymph node assessment\u003csup\u003e\u0026nbsp;[10,11]\u003c/sup\u003e. In the evaluation of mucinous tumors, although some studies suggest that contrast-enhanced sequences may have advantages \u003csup\u003e[14]\u003c/sup\u003e, the simplified protocol in this study did not significantly reduce diagnostic specificity. This may be attributed to the high sensitivity and specificity of DWI combined with ADC value measurements for diagnosing mucinous tumors. Additionally, this study found that T2WI can assess EMVI by observing the morphology of the extramural vascular root and the disappearance of vascular flow voids, which differs from the findings of Volovat et al. \u003csup\u003e[14-17]\u003c/sup\u003e, who argued that contrast-enhanced T1WI has higher sensitivity and specificity in EMVI assessment. This finding further confirms the applicability and reliability of the simplified protocol across different pathological types.\u003c/p\u003e\n\u003cp\u003eThis study retrospectively analyzed 359 patients with pathologically confirmed rectal cancer, comparing the diagnostic performance of the simplified rectal MRI protocol with the standard protocol. The results showed that the simplified protocol achieved comparable accuracy in T staging, sensitivity, and specificity in assessing extramural invasion and detecting lymph node metastasis to the standard protocol (P\u0026gt;0.05). This indicates that by streamlining the scanning sequences (retaining only pelvic sagittal fat-suppressed T2WI, oblique axial T2WI, and DWI), equivalent diagnostic performance can still be maintained. Some hospitals routinely perform additional contrast-enhanced scans, which not only increase the examination time and cost for patients but also pose potential risks associated with contrast agents, such as allergic reactions and nephrotoxicity \u003csup\u003e[18]\u003c/sup\u003e. The simplified protocol, with its significantly shorter scanning time and no need for contrast agents, avoids these risks. This is particularly clinically significant for elderly and frail patients, especially those with rectal cancer requiring multiple follow-ups.\u003c/p\u003e\n\u003cp\u003eDespite the positive results of this study, there are some limitations. First, multicenter prospective studies with homogeneous patient populations are needed to reduce bias in the study results. Second, further investigation into the application of the simplified MRI protocol in different types of rectal cancer patients, such as those with different stages and treatment plans, is warranted. Additionally, considering the advantages of the simplified MRI protocol in detecting small lesions, future research could explore its potential for early rectal cancer screening. Finally, with the development of artificial intelligence and deep learning technologies\u003csup\u003e\u0026nbsp;[16,17,19]\u003c/sup\u003e, future studies could integrate these advanced techniques to further enhance the diagnostic efficacy and accuracy of the simplified MRI protocol.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe simplified rectal MRI scanning protocol provides diagnostic performance equivalent to the standard protocol. Its high sensitivity and specificity help optimize the MRI examination process, reducing patient waiting and scanning times, improving patient comfort, and significantly enhancing MRI image quality by reducing motion artifacts. The simplified protocol offers an efficient and cost-effective alternative for rectal cancer assessment.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eMRI: Magnetic resonance imaging\u003c/p\u003e\n\u003cp\u003eRIS：Radiology Information System\u003c/p\u003e\n\u003cp\u003ePACS：Picture Archiving and Communication System\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eT2WI：T2-weighted imaging\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDWI：diffusion-weighted imaging\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eADC：apparent diffusion coefficient\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMRF：Mesorectal Fascia\u003c/p\u003e\n\u003cp\u003eEMVI：Extramural Vascular Invasion\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData for this study come from Heze Hospital of Shandong Provincial Hospital (Heze Municipal Hospital).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eXiaoxin Zhao collected the cases, processed the data, and drafted and revised the manuscript. Hongzhou Ma proposed the research idea and provided important guidance for this study. All authors helped to write and edit the manuscript, and approved the final version.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that all data supporting the fundings of this study are available within the paper and its source data for the figures and tables in this study are available from the corresponding authors upon request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research adhered to the Declaration of Helsinki and received ethical clearance from the Shandong Provincial Hospital Affiliated Heze Hospital Ethics Committee, waiving participant informed consent requirements under approval code 2025L013.\u003c/p\u003e\n\u003cp\u003eHuman Ethics and Consent to Participate declarations: not applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable for this paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eARNDT K, VIGNA C, KAUL S, et al. Magnetic resonance imaging accuracy in staging early and locally advanced rectal cancer [J]. Surg Oncol, 2023, 101987. DOI: 10.1016/j.suronc.2023.101987.\u003c/li\u003e\n \u003cli\u003eDI COSTANZO G, ASCIONE R, PONSIGLIONE A, et al. Artificial intelligence and radiomics in magnetic resonance imaging of rectal cancer: a review [J]. Explor. Target. Antitumor Ther, 2023, 4(3): 406-421. DOI: 10.1016/j.expotat.2023.04.006.\u003c/li\u003e\n \u003cli\u003eSCABINI S, ROMANA C, SARTINI M, et al. The experience of the COMRE group (REctal COMmittee): can magnetic resonance imaging and endosonography really help the clinical pathway after NCRT in rectal cancer? [J]. Int J Surg, 2023, 109(10): 2991-2995. DOI: 10.1016/j.ijsu.2023.10.010.\u003c/li\u003e\n \u003cli\u003eZHU J, WU X, XUE Y, et al. Prospective analysis of the diagnostic accuracy of digital rectal examination and magnetic resonance imaging for T staging of prostate cancer [J]. J Cancer Res Ther, 2023, 19(4): 1024-1030. DOI: 10.1016/j.jcrt.2023.04.012.\u003c/li\u003e\n \u003cli\u003eMAT\u0026Iacute;AS-GARC\u0026Iacute;A B, MENDOZA-MORENO F, QUIROGA-VALC\u0026Aacute;RCEL A, et al. Is post-neoadjuvant staging by pelvic magnetic resonance imaging (MRI) correct in locally advanced rectal cancer? [J]. Eur J Surg Oncol, 2023, 49(2): e134. DOI: 10.1016/j.ejso.2023.02.001.\u003c/li\u003e\n \u003cli\u003eBEYOND TME COLLABORATIVE. Consensus statement on the multidisciplinary management of patients with recurrent and primary rectal cancer beyond total mesorectal excision planes [J]. Br J Surg, 2024, 100: E1\u0026ndash;E33. DOI: 10.1002/bjs.9192.\u003c/li\u003e\n \u003cli\u003eMOHAMED SHIMY R, MONIR ALY A, ELSHISHTAWY S A, et al. Role of diffusion-weighted magnetic resonance imaging in detection of lymph node metastasis in rectal cancer [J]. Egypt J Radiol Nucl Med, 2024, 55(1): 1-9. DOI: 10.1016/j.ejrnm.2024.01.001.\u003c/li\u003e\n \u003cli\u003eMOROTE J, PAESANO N, PICOLA N, et al. The Role of Digital Rectal Examination for Early Detection of Significant Prostate Cancer in the Era of Magnetic Resonance Imaging [J]. Life, 2024, 14(11): 1359. DOI: 10.3390/life14111359.\u003c/li\u003e\n \u003cli\u003eZHOU D G, HUANG J L, FANG J F, et al. Value of high-resolution magnetic resonance imaging for preoperative evaluation of Denonvilliers fascia in patients with rectal cancer [J]. Chin J Gastrointest Surg, 2021, 24(6): 536-543. DOI: 10.3765/j.issn.1671-0274.2021.06.012.\u003c/li\u003e\n \u003cli\u003eHORVAT N, ROCHA C, OLIVEIRA B C, et al. MRI of Rectal Cancer: Tumor Staging, Imaging Techniques, and Management [J]. Radiographics, 2019, 39(2): 307-321. DOI: 10.1148/rg.2019180114.\u003c/li\u003e\n \u003cli\u003ePredictive value of rectal MRI variables for pathological complete response in locally advanced rectal cancer [J]. Abdom Radiol, 2024. DOI: 10.1007/s00384-024-04801-w.\u003c/li\u003e\n \u003cli\u003eRobinson E, Balasubramaniam R, Hameed M, Clarke C, Taylor SA, Tolan D, Foley KG. Survey of rectal cancer MRI technique and reporting tumour descriptors in the UK: a multi-centre British Society of Gastrointestinal and Abdominal Radiology (BSGAR) audit. Clin Radiol. 2024 Feb;79(2):117-123. doi: 10.1016/j.crad.2023.10.025. Epub 2023 Nov 21. PMID: 37989667.\u003c/li\u003e\n \u003cli\u003eBregendahl S, Bondeven P, Gr\u0026oslash;nborg TK, Brown G, Laurberg S, Pedersen BG. Training of radiology specialists in local staging of primary rectal cancer on MRI: a prospective intervention study exploring the impact of various educational elements on the interpretive performance. BMJ Open Qual. 2022 Aug;11(3):e001716. doi: 10.1136/bmjoq-2021-001716.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eEL HOMSI M, YILDIRIM O, GANGAI N, et al. Contrast-enhanced pelvic magnetic resonance imaging (MRI) for the prediction of treatment response in mucinous rectal cancer [J]. Quant Imaging Med Surg, 2024, 14(6): 4110-4122. DOI: 10.3978/j.qims.2024.06.010.\u003c/li\u003e\n \u003cli\u003eBARBARO B, CARAFAM R P, MINORDI L M, et al. Magnetic resonance imaging for assessment of rectal cancer nodes after chemoradiotherapy: A single center experience [J]. Radiother Oncol, 2024: 110124. DOI: 10.1016/j.radonc.2024.110124.\u003c/li\u003e\n \u003cli\u003eDATTANI M, HEALD R J, GOUSSOUS G, et al. Oncological and survival outcomes in watch and wait patients with a clinical complete response after neoadjuvant chemoradiotherapy for rectal cancer: A systematic review and pooled analysis [J]. Ann Surg, 2024, 268: 955\u0026ndash;967. DOI: 10.1097/SLA.0000000000005196.\u003c/li\u003e\n \u003cli\u003eRENEHAN A G, MALCOMSON L, EMSLEY R, et al. Watch-and-wait approach versus surgical resection after chemoradiotherapy for patients with rectal cancer (the OnCoRe project): A propensity-score matched cohort analysis [J]. Lancet Oncol, 2016, 17(2): 174\u0026ndash;183. DOI: 10.1016/S1470-2045(15)00467-2.\u003c/li\u003e\n \u003cli\u003eOLARIU N, MARALESCU F-M, BOB F, et al. Contrast-Induced Nephropathy in Endovascular Patients: A Retrospective Cohort Study from a Vascular Surgery Clinic in Eastern Europe [J]. J Clin Med, 2025, 14(4): 1172. DOI: 10.3390/jcm14041172.\u003c/li\u003e\n \u003cli\u003eGEUBELS B M, MAAS M, BEETS G L, et al. What to do with suspected nodal regrowth on magnetic resonance imaging during follow-up in an organ preservation approach for rectal cancer [J]. Dis Colon Rectum, 2024, 67(12): 1528-1535. DOI: 10.1097/DCR.0000814379.37407.46.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Rectal cancer, Magnetic resonance imaging, Simplified MRI scanning, Diffusion-weighted MRI","lastPublishedDoi":"10.21203/rs.3.rs-7079111/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7079111/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjective\u003c/strong\u003e: This study aims to evaluate the diagnostic performance of a simplified rectal MRI scanning protocol in the assessment of patients with rectal cancer.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods:\u003c/strong\u003e This retrospective study included patients with newly diagnosed rectal cancer confirmed by pathology who underwent standard rectal MRI scanning. The simplified rectal MRI scanning protocol consisted of the first three sequences of the standard protocol： pelvic sagittal fat-suppressed T2-weighted imaging (T2WI), oblique axial T2WI, and diffusion-weighted imaging (DWI). Four radiologists independently reviewed the images from the simplified and standard rectal MRI scans to assess image quality and observe the primary tumor, extramural invasion, and lymph node metastasis of rectal cancer.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e: A total of 359 patients (198 males and 161 females; mean age = 62.2 ± 6.5 years) were included. 192 patients had extramural invasion, and 146 patients had regional or distant lymph node metastasis. The image quality of the simplified protocol was rated as good or better in 88.3% of cases, which was significantly higher than that of the standard protocol. The T-staging accuracy of the simplified protocol was 97.77%; the sensitivity and specificity for assessing extramural invasion were 97.42% and 92.61%, respectively; and the sensitivity and specificity for detecting lymph node metastasis were 76.47% and 84.20%, respectively. The T-staging accuracy of the standard protocol was 98.89%; the sensitivity and specificity for assessing extramural invasion were 97.39% and 93.64%, respectively; and the sensitivity and specificity for detecting lymph node metastasis were 78.44% and 86.29%, respectively. No statistically significant differences were observed between the two protocols.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e: The simplified rectal MRI scanning protocol demonstrated comparable accuracy in T-staging, as well as sensitivity and specificity in the evaluation of extramural invasion and lymph node metastasis, to the standard rectal MRI scanning protocol. Moreover, the image quality of the simplified protocol is superior to that of the standard protocol. Therefore, the simplified rectal MRI scanning protocol can be used as an alternative to the standard rectal MRI scanning protocol in clinical practice.\u003c/p\u003e","manuscriptTitle":"Analysis of the Diagnostic Performance of a Simplified Rectal Magnetic Resonance Imaging Protocol in the Evaluation of Rectal Cancer","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-11 15:53:48","doi":"10.21203/rs.3.rs-7079111/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"cdd0e7ed-604d-4ca9-bdb7-675b519e44ad","owner":[],"postedDate":"August 11th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-06T06:10:39+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-11 15:53:48","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7079111","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7079111","identity":"rs-7079111","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}