MRI for Rectal Cancer: Updates and Controversies-AJR Expert Panel Narrative Review.

Rectal MRI is a critical tool in the care of patients with rectal cancer, having established roles for primary staging, restaging, and surveillance. The comprehensive diagnostic and prognostic information provided by MRI helps to optimize treatment decision-making. However, challenges persist in the standardization and interpretation of rectal MRI, particularly in the context of rapidly evolving treatment paradigms, including growing acceptance of nonoperative management. In this AJR Expert Panel Narrative Review, we address recent advances and key areas of contention relating to the use of MRI for rectal cancer. Our objectives include: to discuss concepts regarding anatomic localization of rectal tumors; review the evolving rectal cancer treatment paradigm and implications for MRI assessment; discuss updates and controversies regarding rectal MRI for locoregional staging, restaging, and surveillance; review current rectal MRI acquisition protocols; and discuss challenges in homogenizing and optimizing acquisition parameters.