Quantitative analysis of neuronal density in Alzheimer's disease by MR axonography

在磁共振成像的各种对比机制中，表观扩散具有方向依赖性(各向异性扩散)的独特性质，在中枢神经系统中，经验证明各向异性主要起源于轴突。因此，在活体内通过扩散张量分析非侵入性地获得轴突信息是可能的(轴突摄影术)。该项目代表了这种轴突成像方法的临床应用，试图进一步了解退行性神经疾病，如帕金森氏病、肌萎缩侧索硬化症和阿尔茨海默病的病理生理学。该项目成功地引入了轴突造影术中的各种技术，并清楚地表明，对快速轴突血流的定量分析现在在人类身上是可行的。

Among the various contrast mechanics for magnetic resonance (MR) imaging, apparent diffusion possesses the unique property of directional dependency (anisotropic diffusion), In the central nervous system, anisotropism has empirically been shown to primarily originate from axons. It is therefore possible to obtain axonal information in vivo by diffusion tensor analysis, non-invasively, in humans (axonography). The project represents clinical applications of this axonographic method in attempt to obtain further insight into the pathophysiology of degenerative neurological disorders such as Parkinson's disease, amyotrophic lateral sclerosis, and Alzheimer's disease. The project has successfully introduced various techniques in axonography and clearly demonstrates that quantitative analysis of fast axonal flow is now feasible in humans.