Eligible patients with high risk colorectal malignancy (T3/4, spread greater than 5mm, EMVI positive) will have additional surveillance of breath hold T1, T2 and DW-MRIs (no IV contrast) post surgery six monthly for three years. Findings of liver MRIs as reported by radiology PI will be shared with their local MDT who make decisions as appropriate, including the management of any identified liver metastases, according to local protocol.