Method for analyzing data provided by Magnetic Resonance Imaging with dynamic administration of contrast medium in patients with locally advanced rectal cancer, after neoadjuvant radio-chemotherapy, comprising: making available pre- and post-treatment digital images, having one or more regions of interest identified; splitting the regions of interest into portions; calculating first and second time-intensity curves for each portion of the regions of pre- and post-treatment interest, respectively; calculating the maximum signal difference and gradient of the wash-out section for the curves calculated; calculating the median value of the maximum signal difference and of the gradient calculated; calculating the percentage variation between the median values of the maximum signal difference and of the gradient of the wash-out section calculated for each of the first and second curves; linearly combining percentage variations of the maximum signal difference and of the gradient of the wash-out section, to define a relative linear classification index.