Comparison of the Diagnostic Accuracy of 3D Volume Acquisition MRI With CT in Staging Colonic Cancer

• The primary endpoint will be the accuracy of MRI and CT in determining T stage using histology as the gold standard, on a per patient basis. [ Designated as safety issue: No ]
  

• Secondary endpoints will be the accuracy of CT and MRI in determining N stage, depth of invasion beyond the muscularis propria, and EMVI. [ Designated as safety issue: No ]
  
• We will also compare the accuracy of 1.5T against 3.0T MRI scans, and T2 weighted against T1 weighted images [ Designated as safety issue: No ]
  

The patient will proceed with their usual colon cancer assessment and treatment, including colonoscopy with biopsy and histology and preoperative CT chest abdomen and pelvis. In addition, patients who enroll in the study will have 2 preoperative MRIs of their abdomen and pelvis performed. One of these will be performed on a 1.5T and the other will be performed on a 3.0T MRI scanner. We will use 20mg of IM buscopan to reduce bowel mobility for each scan. A coronal scout scan will be taken to identify the tumour and select the target volume. IV gadolinium (a contrast agent routinely used in MRI scans to help identify different tissues) will be administered, and a 3D VIBE scan (T1 weighted) will be performed of the target volume. The liver will also be imaged at this time to look for liver metastases. A T2 weighted 3D volume acquisition will then be obtained of the target volume containing the tumour (and its lymphatic drainage).

The MRI will be independently reported by an expert without knowledge of the results of any other investigations. The results of the MRI scan will then be made available to the clinical team. The patient will then proceed as normal with any other investigation which the clinical team feel is necessary, and be treated as normal for their colon cancer. The patient will proceed with their surgery as normal, and the specimen removed at the time of the operation will be examined in the pathology laboratory to determine the exact stage of the cancer.

The accuracy of CT and MRI in staging colon cancer will then be determined against the reference standard provided by the histology examination.