When a patient is diagnosed with a rectal (bowel) polyp or cancer, radiology doctors read MRI scans to describe how deeply the cancer invades into the bowel wall (this is the 'stage' of the cancer). In this project, we will teach radiologists to find more early-stage rectal cancers. These are cancers that have only grown partially into the bowel wall. If we succeed, more patients could have these lesions removed by a local procedure that preserves the bowel and avoids the risks and complications of major surgery. We have developed a new method for radiology doctors to read MRI scans, which is more accurate than current practice. Currently only 3/10 of early rectal cancers are found by radiologists but by using our MRI reading system, 9/10 patients can be accurately identified as having early rectal cancer. We have proven that we can teach this method to other radiology doctors whose reports help to accurately inform patients of all possible treatment options, so they can be offered the option of a local procedure. In this initial work we will train radiology doctors in our MRI reading method in 20 hospitals. We will compare MRI reports before and after training to see if an accurate reading method improves treatments choices for patients. We will also determine whether more patients have local procedures after our training. The results of this initial work will help us to apply for national funding for a trial that we can quickly roll out to all NHS hospitals.