Application of Rotational Tensor Interpolation to Tractography

Introduction: Diffusion MRI was the first imaging modality to allow the visualization of white matter fibre paths in vivo, and non-invasively. The process by which the white matter tracts are reconstructed from diffusion tensor data is called tractography. Tensor interpolation methods have often been used to improve the reproducibility and reliability of tractography results (e.g [1]). In this abstract we will introduce a new method for 3D tensor interpolation based on work by Batchelor [2], and use simulated data to compare its performance to well established methodologies. Methods: Rotational Interpolation: In [2] Batchelor et al describe a novel interpolation method between two positive definite tensors called rotational anisotropy. According to this method, the interpolated tensor, D(s), between tensors D1 and D2 will be given by: T s s s R s R s D ) ( ) ( ) ( ) 1 2 1 − Λ Λ = where Λi is a diagonal matrix with the eigenvalues of tensor Di along the diagonal, and R(s) is given by: