Staging of Rectal Cancer: MRI Protocol, Pelvic Anatomy, and Definitions

Abstract

Rectal carcinoma is a prevalent and increasingly diagnosed cancer globally, posing significant mortality and morbidity risks, particularly among younger individuals. Prognosis hinges on several factors, such as site of involvement (upper rectum vs. lower rectum), tumor extension into surrounding tissues, involvement of critical structures like the mesorectal fascia and vessels, and the presence of distant metastases. Treatment approaches are tailored to the tumor's location and extent. Diagnostic tools including digital rectal examination and various imaging modalities like computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography-CT play crucial roles in staging, identifying high-risk patients needing neoadjuvant chemoradiotherapy (CRT), and monitoring treatment response. MRI stands out as the preferred modality for locoregional staging, detecting adverse prognostic indicators, assessing post-CRT changes, and long-term surveillance due to its superior contrast resolution. This review discusses the key concepts in the application of MRI to rectal cancer imaging.

Keywords

anorectal junction - circumferential resection margin - mesorectal fascia - MRI - rectal carcinoma

Publication History

Article published online:
12 June 2025

• References

• 1 Siegel RL, Wagle NS, Cercek A, Smith RA, Jemal A. Colorectal cancer statistics, 2023. CA: A Cancer Journal for Clinicians 2023; 73: 233-254
• 2 Arya S, Das D, Engineer R, Saklani A. Imaging in rectal cancer with emphasis on local staging with MRI. Indian J Radiol Imaging 2015; 25 (02) 148-161
• 3 Benson AB, Venook AP, Al-Hawary MM. et al. Colon cancer, version 2.2021, NCCN clinical practice guidelines in oncology. J Nat Comprehensive Cancer Network 2021; 19: 329-359
• 4 Duzova M, Basaran H, Inan G, Gul OV, Eren OO, Korez MK. Preoperative versus postoperative chemoradiotherapy for locally advanced rectal cancer: outcomes of survival, toxicity, sphincter preserving and prognostic factors. Transpl Immunol 2021; 69: 101489
• 5 Schrag D, Shi Q, Weiser MR. et al. Preoperative treatment of locally advanced rectal cancer. N Engl J Med 2023; 389 (04) 322-334
• 6 Kaur H, Gabriel H, Awiwi MO. et al. Anatomic basis of rectal cancer staging: clarifying controversies and misconceptions. Radiographics 2024; 44 (07) e230203
• 7 DʼSouza N, de Neree Tot Babberich MPM, d'Hoore A. et al. Definition of the rectum: an international, expert-based Delphi consensus. Ann Surg 2019; 270 (06) 955-959
• 8 Kraima AC, West NP, Treanor D. et al. Understanding the surgical pitfalls in total mesorectal excision: investigating the histology of the perirectal fascia and the pelvic autonomic nerves. Eur J Surg Oncol 2015; 41 (12) 1621-1629
• 9 Beets-Tan RGH, Lambregts DMJ, Maas M. et al. Magnetic resonance imaging for clinical management of rectal cancer: Updated recommendations from the 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus meeting. Eur Radiol 2018; 28 (04) 1465-1475
• 10 Maas M, Lambregts DMJ, Lahaye MJ. et al. T-staging of rectal cancer: accuracy of 3.0 Tesla MRI compared with 1.5 Tesla. Abdom Imaging 2012; 37 (03) 475-481
• 11 Alberda WJ, Dassen HPN, Dwarkasing RS. et al. Prediction of tumor stage and lymph node involvement with dynamic contrast-enhanced MRI after chemoradiotherapy for locally advanced rectal cancer. Int J Colorectal Dis 2013; 28 (04) 573-580
• 12 Patel UB, Taylor F, Blomqvist L. et al. Magnetic resonance imaging-detected tumor response for locally advanced rectal cancer predicts survival outcomes: MERCURY experience. J Clin Oncol 2011; 29 (28) 3753-3760
• 13 Armbruster M, D'Anastasi M, Holzner V. et al. Improved detection of a tumorous involvement of the mesorectal fascia and locoregional lymph nodes in locally advanced rectal cancer using DCE-MRI. Int J Colorectal Dis 2018; 33 (07) 901-909
• 14 Gollub MJ, Gultekin DH, Akin O. et al. Dynamic contrast enhanced-MRI for the detection of pathological complete response to neoadjuvant chemotherapy for locally advanced rectal cancer. Eur Radiol 2012; 22 (04) 821-831
• 15 Hötker AM, Garcia-Aguilar J, Gollub MJ. Multiparametric MRI of rectal cancer in the assessment of response to therapy: a systematic review. Dis Colon Rectum 2014; 57 (06) 790-799
• 16 Tong T, Sun Y, Gollub MJ. et al. Dynamic contrast-enhanced MRI: use in predicting pathological complete response to neoadjuvant chemoradiation in locally advanced rectal cancer. J Magn Reson Imaging 2015; 42 (03) 673-680
• 17 Brown G, Daniels IR, Richardson C, Revell P, Peppercorn D, Bourne M. Techniques and trouble-shooting in high spatial resolution thin slice MRI for rectal cancer. Br J Radiol 2005; 78 (927) 245-251
• 18 Chambers WM, Khan U, Gagliano A, Smith RD, Sheffield J, Nicholls RJ. Tumour morphology as a predictor of outcome after local excision of rectal cancer. Br J Surg 2004; 91 (04) 457-459
• 19 Klessen C, Rogalla P, Taupitz M. Local staging of rectal cancer: the current role of MRI. Eur Radiol 2007; 17 (02) 379-389
• 20 Sinaei M, Swallow C, Milot L, Moghaddam PA, Smith A, Atri M. Patterns and signal intensity characteristics of pelvic recurrence of rectal cancer at MR imaging. Radiographics 2013; 33 (05) E171-E187
• 21 Delli Pizzi A, Basilico R, Cianci R. et al. Rectal cancer MRI: protocols, signs and future perspectives radiologists should consider in everyday clinical practice. Insights Imaging 2018; 9 (04) 405-412
• 22 Glimelius B, Tiret E, Cervantes A, Arnold D. ESMO Guidelines Working Group. Rectal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol 2013; 24 (Suppl. 06) vi81-vi88
• 23 Weiser MR. AJCC 8th edition: colorectal cancer. Ann Surg Oncol 2018; 25 (06) 1454-1455
• 24 Consorti F, Lorenzotti A, Midiri G, Di Paola M. Prognostic significance of mucinous carcinoma of colon and rectum: a prospective case-control study. J Surg Oncol 2000; 73 (02) 70-74
• 25 Bates DDB, Homsi ME, Chang KJ, Lalwani N, Horvat N, Sheedy SP. MRI for rectal cancer: staging, mrCRM, EMVI, lymph node staging and post-treatment response. Clin Colorectal Cancer 2022; 21 (01) 10-18
• 26 McCourt M, Armitage J, Monson JRT. Rectal cancer. Surgeon 2009; 7 (03) 162-169
• 27 Detering R, van Oostendorp SE, Meyer VM. et al; Dutch ColoRectal Audit Group*. MRI cT1-2 rectal cancer staging accuracy: a population-based study. Br J Surg 2020; 107 (10) 1372-1382
• 28 Ghoneem E, Shabana ASA, El Sherbini M. et al. Endoluminal ultrasound versus magnetic resonance imaging in assessment of rectal cancer after neoadjuvant therapy. BMC Gastroenterol 2022; 22 (01) 542
• 29 Oien K, Forsmo HM, Rösler C, Nylund K, Waage JE, Pfeffer F. Endorectal ultrasound and magnetic resonance imaging for staging of early rectal cancers: how well does it work in practice?. Acta Oncol 2019; 58 (sup1): S49-S54
• 30 Opara CO, Khan FY, Kabiraj DG. et al. The value of magnetic resonance imaging and endorectal ultrasound for the accurate preoperative T-staging of rectal cancer. Cureus 2022; 14 (10) e30499
• 31 Taylor FGM, Swift RI, Blomqvist L, Brown G. A systematic approach to the interpretation of preoperative staging MRI for rectal cancer. AJR Am J Roentgenol 2008; 191 (06) 1827-1835
• 32 Chen Y, Guo R, Xie J, Liu Z, Shi P, Ming Q. Laparoscopy combined with transanal endoscopic microsurgery for rectal cancer: a prospective, single-blinded, randomized clinical trial. Surg Laparosc Endosc Percutan Tech 2015; 25 (05) 399-402
• 33 Lindsetmo RO, Joh YG, Delaney CP. Surgical treatment for rectal cancer: an international perspective on what the medical gastroenterologist needs to know. World J Gastroenterol 2008; 14 (21) 3281-3289
• 34 Benson AB, Venook AP, Al-Hawary MM. et al. Colon cancer, version 2.2021, NCCN clinical practice guidelines in oncology. J Natl Compr Canc Netw 2021; 19 (03) 329-359
• 35 Borgheresi A, De Muzio F, Agostini A. et al. Lymph nodes evaluation in rectal cancer: where do we stand and future perspective. J Clin Med 2022; 11 (09) 2599
• 36 Kaur H, Ernst RD, Rauch GM, Harisinghani M. Nodal drainage pathways in primary rectal cancer: anatomy of regional and distant nodal spread. Abdom Radiol (NY) 2019; 44 (11) 3527-3535
• 37 Arian A, Taher HJ, Suhail Najm Alareer H, Aghili M. Value of conventional MRI, DCE-MRI, and DWI-MRI in the discrimination of metastatic from non-metastatic lymph nodes in rectal cancer: a systematic review and meta-analysis study. Asian Pac J Cancer Prev 2023; 24 (02) 401-410
• 38 Mir N, Sohaib SA, Collins D, Koh DM. Fusion of high b-value diffusion-weighted and T2-weighted MR images improves identification of lymph nodes in the pelvis. J Med Imaging Radiat Oncol 2010; 54 (04) 358-364
• 39 Nakai G, Matsuki M, Inada Y. et al. Detection and evaluation of pelvic lymph nodes in patients with gynecologic malignancies using body diffusion-weighted magnetic resonance imaging. J Comput Assist Tomogr 2008; 32 (05) 764-768
• 40 Gollub MJ, Arya S, Beets-Tan RG. et al. Use of magnetic resonance imaging in rectal cancer patients: Society of Abdominal Radiology (SAR) rectal cancer disease-focused panel (DFP) recommendations 2017. Abdom Radiol (NY) 2018; 43 (11) 2893-2902
• 41 Lambregts DMJ, Heijnen LA, Maas M. et al. Gadofosveset-enhanced MRI for the assessment of rectal cancer lymph nodes: predictive criteria. Abdom Imaging 2013; 38 (04) 720-727
• 42 Renzulli M, Clemente A, Ierardi AM. et al. Imaging of colorectal liver metastases: new developments and pending issues. Cancers (Basel) 2020; 12 (01) 151
• 43 Pangarkar SY, Baheti AD, Mistry KA. et al. Prognostic significance of EMVI in rectal cancer in a tertiary cancer hospital in India. Indian J Radiol Imaging 2021; 31 (03) 560-565
• 44 Battersby NJ, How P, Moran B. et al; MERCURY II Study Group. Prospective validation of a low rectal cancer magnetic resonance imaging staging system and development of a local recurrence risk stratification model: the MERCURY II study. Ann Surg 2016; 263 (04) 751-760
• 45 Tripathi P, Rao SX, Zeng MS. Clinical value of MRI-detected extramural venous invasion in rectal cancer. J Dig Dis 2017; 18 (01) 2-12
• 46 KSAR Study Group for Rectal Cancer. Essential items for structured reporting of rectal cancer MRI: 2016 consensus recommendation from the Korean Society of Abdominal Radiology. Korean J Radiol 2017; 18 (01) 132-151