Fig. 15

Mucin-producing tumours are particularly difficult to evaluate after neo-adjuvant treatment. The difference between sagittal TSE images before (a) and after treatment (b) (1.5 T) can only be seen in findings such as mucosal oedema of the lower rectum (white arrow), and presacral oedema (black arrow). The tumour itself and it extension outside the rectum (hatched arrows) are virtually unchanged