This paper aims to give an overview of the various clinical applications of DWI and discuss their potential role for rectal cancer imaging. PRiMARy RectAl cANceR stAgiNg Rectal tumour detection The main goal of MRI for rectal cancer is staging rather than tumour detection, since typically the presence of tumour has already been established by endoscopy or CT-colonography. 2 It is probably therefore that only a few studies have focused on DWI for the primary detection of rectal cancer. 3-10 Nevertheless, published reports have shown consistently good results for DWI to detect rectal tumours. In a recent meta-analysis, albeit focusing on colorectal tumours in general and not specifically on rectal cancer, pooled sensitivity, specificity and area under the curve (AUC) were 95%, 93% and 0.98, respectively. 11

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