Evaluation of Medical Image Registration by Using 3D SIFT and Phase-Only Correlation.

An effective method for quantitatively evaluating rigid and non-rigid image registration without any manual assessment is proposed. This evaluation method is based on feature point detection in reference images and corresponding point localization in registered floating images. For feature point detection, a 3D SIFT keypoint detector is applied to determine evaluation reference points in liver vessel regions of reference images. For corresponding point localization, a 3D phase-only correlation approach is applied to match reference points and their corresponding points. Distance between the reference points and the correspondences can be used to estimate image registration errors. With the proposed method, users can evaluate different registration algorithms using their own image data automatically.