A system automatically processes different medical image sequences facilitating comparison of the sequences in adjacent respective display areas. An image data processor, identifies first and second mask images of first and second image sequences respectively as images preceding introduction of contrast agent and determines a translational shift between the first and second mask images. The image data processor transforms data representing individual images of at least one of the first image sequence and the second image sequence in response to the determined translational shift to reduce mis-alignment of the individual images of the first image sequence relative to the individual images of the second image sequence. A display presents first and second image sequences corrected for mis-alignment, in substantially adjacent display areas to facilitate user comparison.