Automated initialization and region of interest detection for successful head registration of truncated CT/MR head & neck images

Maximization of a voxel based similarity metric like mutual information is the state of the art for the multimodal rigid registration of the head. To achieve satisfactory results the transform needs to be initialized properly and the region of interest (ROI) containing only rigid structures has to be defined in both images. In this paper we present and comprehensively evaluate an automated initialization and ROI detection method that enables the fully automated rigid registration of routinely gathered head CT and MR images.