新しいアルゴリズムによる拡散テンソルトラクトグラフィー : Diffusion-Tensor Tractography Based on Directional Diffusion Function:
Diffusion-tensor(DT)tractography is an image analysis method that allows for visualization of specific white matter tract in the brain in vivo. This new technique has been used to visualize the pyramidal tract, which conveys electrical signal from neurons in the primary motor cortex to the spinal cord, in planning for brain tumor surgery. Conventional tractography based on the “streamline” method only partially visualizes the pyramidal tract because of fiber crossing with other white matter tracts. To overcome the crossing-fiber problem, we developed a new tractography method which is based on directional diffusion function(DDF). We applied DDF tractography method to MRI data of brain tumor patients as well as healthy subjects, and found that DDF-based method was able to visualize the pyramidal tract to a larger extent than conventional techniques do, and that the estimated tracts were consistent with anatomical knowledge. To further validate the DDF-based tractography method, we studied the somatotopic organization of the pyramidal tract in the posterior limb of the internal capsule(PLIC). Estimated organization of the fiber bundles of the pyramidal tract in the PLIC was consistent with anatomically known somatotopic organization, which supported the validity of the DDF-based tractography method.
医用画像情報学会雑誌 25(1), 5-8, 2008