脳白質線維トラクトグラフィーと定量解析

White Matter Fiber Tractography and Quantitative Analysis of Diffusion Tensor Imaging

拡散MRI像は非侵襲的に生体脳の白質路を同定，計測しうる唯一の手法である。連合線維は大脳半球内の異なる部位の皮質間を結ぶ。投射線維は大脳皮質と脊髄など他の中枢神経を結ぶ。大脳の左右半球間を結ぶ線維を交連線維と呼ぶ。拡散テンソル像を用いた定量解析手法には，関心領域法，白質路を描出し計測するtract-specific analysis，全脳解析法の3つに大別される。

Abstract

Magnetic resonance diffusion tensor imaging (DTI) is a noninvasive technique that can identify and quantify white matter tracts by evaluating the diffusion of water in biological tissues. While association fibers are bundles of axons within the brain that unite different parts of the same cerebral hemisphere, projection fibers are bundles of axons that unite the cortex with lower parts of the brain and the spinal cord. The commissural fibers are axon bundles that connect the two hemispheres of the brain. Quantitative analysis of DTI can be roughly classified into three types: region of interest analysis, tract-specific analysis, and fully automated hypothesis free whole brain analysis.