A method of registering a 4D contrast enhanced image data set, wherein the 4D contrast enhanced image data set includes image data of the same volume of interest acquired at different timeframes with changing contrast enhancement, the volume of interest includes moving structure, and the different timeframes correspond to a predetermined motion phase of interest in different motion cycles of the moving structure, the method, comprising: registering image data corresponding to a plurality of the different timeframes with reference image from one of the timeframes.