Evaluation of polynomial image deformation using anatomical landmarks for matching of 3D-abdominal MR-images and for atlas construction

While a variety of different deformation algorithms have been implemented f or matching of skull, few attempts in matching areas in abdomen have been r eported. In this study we evaluate the usability of first and second order polynomial 3D-warping for this purpose. We match abdominal MR-images from d ifferent individuals using manually picked anatomical landmarks. Generation of transformation coefficients was done through a linear regress ion technique that employs a least square fit using the reference landmarks . The landmarks were picked in a predefined order, well spread over the ent ire data set, by a radiologist. The image resampling was done using linear interpolation and the evaluation was performed visually as well as by calcu lating the cross correlation and the normalized least squared error between the original image and the transformed image. Our preliminary results reveal that the second order polynomial transformat ion using landmarks is a robust and efficient method. It is also superior t o the second order one, for image deformation in the abdominal region and i t may be used in atlas generation as well as in multimodality image coregis tration and fusion.