3-D segmentation of medical structures by integration of raycasting with anatomic knowledge

Abstract We present a graphically interactive procedure which is used to register a digital anatomic brain atlas with the tomographic patient volume. Patient structures to be segmented are outlined by local elastic deformation of corresponding objects from the anatomy model. This is performed in voxel space using a cost minimization procedure. The anatomic knowledge acquired in this manner is stored in a patient specific volume dataset and guides a raycaster with respect to the localization of object surfaces in order to control the result of the deformation process. Thus objects, which so far could not have been segmented appropriately or only after tedious manual editing efforts, become accessible by physicians. We present several results demonstrating the high quality and practicality of the method.