Multimodal imaging evaluation in staging of rectal cancer

Figure 5 Combination of high-resolution magnetic resonance imaging with diffusion-weighted imaging and positron emission tomography/computed tomography for assessing tumor response after neoadjuvant chemoradiotherapy. A-C: T2-weighted magnetic resonance image (MRI) (A), diffusion-weighted imaging (DWI) (B), and positron emission tomography (PET)/computed tomography (CT) (C) obtained before chemoradiotherapy (CRT) shows a T3 tumor (arrows) with the restricted diffusion and intense hyper-metabolism; D-F: After CRT, T2-weighted MRI (D) shows a marked decrease in the tumor size. DWI (E) shows the focal diffusion restriction confined to the rectal wall, corresponding to histological proven T2 lesion. PET/CT (F) also demonstrates the good tumor response to CRT.