1. A method for identifying, within volume scan comprising a sequence of a plurality of scan slices and in which there is difference of intensity between normal and pathological regions, a subset of said scan slices which include pathological tissue, each scan slice being an image composed of respective intensity values for each of an array of pixels, the method comprising: a. obtaining a respective slice parameter for each scan slice using percentiles of the distribution of the intensity of the pixels of the corresponding slices, the slice parameter characterizing the shape of the distribution of intensities of the pixels of a corresponding scan slice; b. generating a curve of the slice parameter for a sequence of scan slices; and c. identifying said scan slices which include pathological tissue using the curve, as a range of scan slices for which a corresponding slice parameter indicates that there is a relatively high number of high intensity pixels.