Bilateral Filtering of Diffusion Tensor Magnetic Resonance Images

Ghassan Hamarneh, Judith Hradsky
2007 IEEE Transactions on Image Processing  
We extend the well-known scalar image bilateral filtering technique to diffusion tensor magnetic resonance images (DTMRI). The scalar version of bilateral image filtering is extended to perform edge-preserving smoothing of DT field data. The bilateral DT filtering is performed in the Log-Euclidean framework which guarantees valid output tensors. Smoothing is achieved by weighted averaging of neighboring tensors. Analogous to bilateral filtering of scalar images, the weights are chosen to be
more » ... rsely proportional to two distance measures: The geometrical Euclidean distance between the spatial locations of tensors and the dissimilarity of tensors. We describe the noniterative DT smoothing equation in closed form and show how interpolation of DT data is treated as a special case of bilateral filtering where only spatial distance is used. We evaluate different recent DT tensor dissimilarity metrics including the Log-Euclidean, the similarity-invariant Log-Euclidean, the square root of the J-divergence, and the distance scaled mutual diffusion coefficient. We present qualitative and quantitative smoothing and interpolation results and show their effect on segmentation, for both synthetic DT field data, as well as real cardiac and brain DTMRI data. Index Terms-Bilateral filtering, diffusion tensor magnetic resonance imaging (DTMRI), interpolation, smoothing. Analysis Laboratory (MIAL), Simon Fraser University. His main research interests are medical image processing, segmentation and registration, and anatomical shape modelling and analysis. Judith Hradsky, received the B.S. and Diplom degree in computational visualistics from the Otto-von-Guericke University,
doi:10.1109/tip.2007.904964 pmid:17926929 fatcat:2ab76pl5jvhofbw6z7qkm7owzi