The role of MRI in the pre‐operative staging of rectal cancer
Pre‐operative local staging in patients with rectal cancer can be used to:
- Assign the most appropriate pre‐operative adjuvant therapy;
- Assist in surgical planning;
- Serve as an accurate baseline from which to compare the success of different treatment strategies.
In image interpretation, the following prognostic information should be sought:
- Tumour T stage;
- The depth of extramural spread of tumour (depth beyond outer muscle wall);
- The relationship of the tumour to the peritoneal reflection;
- The relationship of the tumour to the anal sphincter complex;
- The distance from the outermost edge of the tumour to the mesorectal fascia;
- The presence and location of mesorectal deposits;
- The presence of other prognostic factors, such as extramural venous invasion and peritoneal invasion.