A medical data processing method of segmenting image features in medical images generated with different imaging modalities, wherein the image features represent a corresponding anatomical structure in each of the medical images, the method being constituted to be executed by a computer and comprising the following steps: a) acquiring first modality medical image data describing a first modality medical image containing a first modality image representation of the anatomical structure; b) acquiring second modality medical image data describing a second modality medical image containing a second modality image representation of the anatomical structure; c) determining, based on the first modality medical image data and the second modality medical image data, modality transformation data describing a mapping transformation between the image information in the first modality image data and the image information in the second modality medical image data; d) acquiring colour value data describing a colour value of the image elements in the first modality medical image and in the second modality medical image, wherein the colour value data comprises colour value sets of colour values for each one of the image elements in the first modality image representation and the second modality image representation, wherein each member of a set describes the colour value of one of the image elements in either the first modality image representation or the second modality image representation; e) determining (S2 - S7), based on the first modality medical image data, first modality segmentation data describing the result of segmenting the first modality image representation from the first modality medical image data; f) determining (S8 - S10), based on the first modality segmentation data and the modality transformation data and the colour value data, second modality segmentation data describing a result of segmenting the second modality image representation from the second modality medical image data, characterised in that g) determining the second modality segmentation data comprises correlating the colour value sets based on correlating the colour values of image elements of the second modality medical image with the colour values of the image elements which correspond to image elements of the first modality medical image which represent the first modality image representation as defined by the mapping transformation. a) acquiring first modality medical image data describing a first modality medical image containing a first modality image representation of the anatomical structure; b) acquiring second modality medical image data describing a second modality medical image containing a second modality image representation of the anatomical structure; c) determining, based on the first modality medical image data and the second modality medical image data, modality transformation data describing a mapping transformation between the image information in the first modality image data and the image information in the second modality medical image data; d) acquiring colour value data describing a colour value of the image elements in the first modality medical image and in the second modality medical image, wherein the colour value data comprises colour value sets of colour values for each one of the image elements in the first modality image representation and the second modality image representation, wherein each member of a set describes the colour value of one of the image elements in either the first modality image representation or the second modality image representation; e) determining (S2 - S7), based on the first modality medical image data, first modality segmentation data describing the result of segmenting the first modality image representation from the first modality medical image data; f) determining (S8 - S10), based on the first modality segmentation data and the modality transformation data and the colour value data, second modality segmentation data describing a result of segmenting the second modality image representation from the second modality medical image data,