MR imaging of Rectal Cancer

MR imaging strengthens contemporary management of rectal cancer by depicting tumor extent, mesorectal fascia proximity, and nodal disease with exquisite anatomic detail. Both standardized technique and synoptic reporting improve reproducibility and multidisciplinary planning. Accurate T-category assignment, measurement of the circumferential resection margin, and recognition of extramural vascular invasion/tumor deposits stratify risk and help to triage patients into surgical, neoadjuvant or "watch-and-wait" pathways. Station-based evaluation of lateral pelvic nodes is critical to develop local control strategies. On restaging, a descriptive T2 + diffusion-weighted imaging framework differentiates treatment-related fibrosis from residual tumor to support organ-preserving options when appropriate.