A method and system are provided for creating and simultaneously displaying medical scan images, from each of first (780) and second (530) medical scan datasets, obtained by scanning a 3-dimensional (3-D) object with different scanning modalities. A first image (410) is derived from the first (780) dataset, the first image (410) lying in a first plane corresponding to an acquisition plane of the first (780) dataset. A second image (420) is obtained from the second dataset (530), the second image also lying in the first plane. The second image may be obtained by re-slicing the second data set. One or both medical scan datasets may be multivolume datasets. The invention may improve viewing resolution and/or speed, when viewing a multi-series MRI scan together with a CT and/or a PET scan.