Xiujuan Geng1, Hong Gu1, Wang Zhan2, Wanyong Shin1, Yi-Ping Chao3, Norbert Schuff, Ching-Po Lin4, Yihong Yang1
1Neuroimaging, National Institute on Drug Abuse, NIH, Baltimore, MD, United States; 2Department of Radiology, University of California, San Francisco; 3Department of Electrical Engineering, National Taiwan University, Taiwan; 4Institute of Brain Science, National Yang-Ming University, Taiwan
We propose a novel diffeomorphic registration method for diffusion MRI data by mapping their orientation distribution functions (ODFs) represented with spherical harmonics (SHs). The registration is based on optimizing a diffeomorphic demons cost function. ODF reorientation is performed by rotating the SH coefficients to maintain the consistency with the local fiber orientations. Rotation on SH coefficients avoids the estimation of principle directions which has no analytical solution and is time consuming. The performance was tested using different SH orders. Results show that registration with higher orders improves the registration accuracy in terms of smaller similarity error and higher directional consistency.