Magnetic resonance imaging for diagnosis and neoadjuvant treatment evaluation in locally advanced rectal cancer: A pictorial review

High-resolution pelvic magnetic resonance imaging (MRI) is the primary method for staging rectal cancer.MRI is highly accurate in the primary staging of rectal cancer; however, it has not proven to be effective in restaging, especially in complete response evaluation after neoadjuvant therapy.Neoadjuvant chemoradiotherapy produces many changes in rectal tumors and on adjacent area, as a result, local tumor extent may not be accurately determined.However, adding diffusion-weighted sequences to the standard approach can improve diagnostic accuracy.In this pictorial review, an overview of the situation of MRI in the staging and re-staging of rectal cancer is exhibited as a pictorial assay.An experience-and literature-based discussion of limitations and difficulties in interpretation are also presented.