A method for validating non-rigid image registration includes acquiring a source image and a target image. Registration is performed from source image to target image using a non-rigid registration technique to produce forward transformation map. Registration is performed from the target image back to the source image using the non-rigid registration technique to produce a backward transformation map. Consistency registration error is measured as an indication of a change in local volume of the source with respect to the target image using the produced forward transformation map and the produced backward transformation map. The non-rigid registration technique is validated based on the measured consistency registration error.