Fig. 4

Axial TSE image (1.5 T) of the pelvis at the level of a mid-rectal cancer. The intact muscularis propria is seen as a thin dark band on the left side where no tumour is present (solid arrow). The mesorectal fascia is also marked by the dotted arrows. Both the muscularis propria and the mesorectal fascia are visible as a thin low-signal layer and line, respectively. However the imaging plane should meet these structures perpendicularly for optimal demonstration