MRI Local Staging and Restaging in Rectal Cancer.

Magnetic resonance imaging (MRI) with rectal protocol modification is a reliable staging modality which is rapidly replacing transrectal ultrasound for staging. The added information delivered by MRI includes wide circumferential radial margin compromise, distant lymph node metastasis in the pelvis, and level of sphincter compromise in the low rectum. As more information becomes available through ongoing studies, MRI may be able to contribute the decision to treat rectal cancer nonoperatively.