1. A method combining a plurality of image data sets into one multi-fused image for display to a user, comprising in a processor: (a) aligning all image data sets with a data set representing corresponding anatomical data; (b) segmenting the image data in each data set into separate regions representing respective structures of interest by reference to a segmentation derived from anatomical data; (c) for each region, selecting a corresponding segment of image data from a selected image data set; and (d) combining the selected segments of the image data set to generate the multi-fused image of the regions, by applying spatially dependent look-up tables to the plurality of image data sets, thereby to determine whether each data set is hidden or displayed for each region, and making the multi-fused image of the regions available in electronic form from said processor.