Automatic detection of fiducial marker center based on shape index and curvedness

Abstract

Fiducial marker is widely used for registration in image guided neurosurgery. In this paper we propose a novel automatic approach of localizing the center of these markers in CT volume. We first segment the volume into three parts according to shape index and curvedness of each voxel. Part1 includes some voxels on top of the markers, part2 includes some voxels at the bottom of the markers, and part3 is the background. Then we cluster voxels in part1 and part2 separately. The result groups in part1 are candidates for the top of markers, and the groups in part2 are candidates for bottom. For each group in part2, if there is a group in part1 that is close to it, this pair is regarded as a marker and the centroid of the group from part2 is the marker center. Experiments show that the marker center can be localized with sub millimeter accuracy. © 2008 Springer-Verlag Berlin Heidelberg.