1. A medical imaging system comprising: one or more displays; a viewer device configured to generate an interactive user interface screen on the one or more displays, which viewer device enables a user to simultaneously inspect selected image data of multiple patients or multiple images; and a registration device configured to: select image data and identify a global reference image having a global image frame of reference in the selected image data, determine a first registration matrix which aligns a first selected image with the global reference image, wherein determining the first registration matrix comprises: defining the first registration matrix based on a priori information if the registration between the first selected image is known a priori; and defining an identity matrix as the first registration matrix if a frame of reference of the first selected image is the same as the global image frame of reference; compare a frame of reference of remaining images to the frame of reference of the first selected image, and propagate the first registration matrix to the images whose frames of reference coincide with the frame of reference of the first selected image.