Figure 2. Location matched (a) T₁ weighted and (b) T₂ weighted images of the rectum and pelvic sigmoid colon with heterogeneous faecal material. These images also demonstrate the potential value of comparing multiple sequences to aid differentiation between lesions and intraluminal faeces. On T₁ weighting (a) the area indicated (thick arrow) is of similar signal to the bowel wall and therefore could be tumour. T₂ weighted (b) however demonstrates good negative luminal contrast in this region: no tumour is present. However this strategy is clearly limited: it would be impossible to exclude a lesion in either image at the area indicated by the thin arrow.