1. Image processing device for processing medical image data showing at least two image objects, including a segmentation unit for detection and/or segmentation of image objects in said image data, said segmentation unit comprising: a selection unit for selecting a target object for detection and/or segmentation and an intermediary object in said image data, which is easier detectable than said target object and for which position information about the spatial relationship to said target object are known, an intermediary object segmentation unit for segmentation of said intermediary object in said image data, and a target object detection unit for detection and/or segmentation of said target object in said image data using said segmented intermediary object and said position information about the spatial relationship of said intermediary object to said target object.