Figure 7. (a) T₁ weighted (repetition time (TR)=500 ms, echo time (TE) 10 ms) and (b) T₂ fast spin echo (FSE) (TR>3000 ms, TE 105 ms) axial images of rectal tumour. The bowel wall layers cannot be seen on the T₁ weighted images. Vessels (arrowhead), lymph node (arrow), tumour (open arrow) and muscle coat (curved arrow) all return very similar signal intensities making distinction between structures difficult on the T₁ weighted image. This compares with the T₂ weighted image, which shows clear separation of tumour and bowel wall layers due to high inherent tissue contrast.