Abstract: A method and system for acquiring information on lesions in dynamic 3D medical images of a body region and/or organ, having the steps: applying a registration technique to align a plurality of volumetric image data of the body region and/or organ, yielding multi-phase registered volumetric image data of the body region and/or organ; applying a hierarchical segmentation on the multi-phase registered volumetric image data of the body region and/or organ, the segmentation yielding a plurality of clusters of n-dimensional voxel vectors of the multi-phase aligned volumetric image; determining from the plurality of clusters a cluster or set of clusters delineating the body and/or organ; identifying the connected region(s) of voxel vectors belonging to the body region and/or organ; refining/filling the connected region(s) corresponding to the body region and/or organ; reapplying the segmentation step to the refined/filled connected region(s) corresponding to the body region and/or organ, to obtain a more accurate se