Establishment of MRI Model for pTRG in Rectal Cancer With Establishment of

This study proposeto integrate a variety of imaging quantitative indicators to establish a new MRI-based tumor response regression(mrTRG) classification method. The accuracy of the established mrTRG classification method according pathology TRG(pTRG) will be tested. The ability of the established mrTRG classification method to predict prognosis will also be tested.

The study included two part: one is a retrospective single-center cohort for analyzing quantitative MRI factors associated with pTRG, from which a new MRI-based tumor response regression(mrTRG) classification method will be established. The other is a prospective multi-center cohort for testing the accuracy of the established mrTRG classification according to pTRG; and also for validating the established mrTRG classification associated with survival.