Yasmin Hasina, Nakata Yasuhiro, Aoki Shigeki, Abe Osamu, Sato Noriko, Nemoto Kiyotaka, Arima Kunimasa, Furuta Nobuo, Uno Masatake, Hirai Shigeo, Masutani Yoshitaka, Ohtomo Kuni
Department of Radiology, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
Neuroradiology. 2008 Apr;50(4):293-9. doi: 10.1007/s00234-007-0353-7. Epub 2008 Feb 2.
Our aim was to determine diffusion abnormalities in the uncinate fasciculus (UF) in Alzheimer's disease (AD) by diffusion tensor tractography (DTT) using a new method for measuring the core of the tract.
We studied 19 patients with AD and 19 age-matched control subjects who underwent MRI using diffusion tensor imaging (DTI). DTT of the UF was generated. The mean diffusivity (MD) and fractional anisotropy (FA) of the core of the tract were measured after voxelized tract shape processing. Student's t-test was used to compare results between patients with AD and controls. Intraobserver correlation tests were also performed.
FA was significantly lower (P < 0.0001) in the UF of patients with AD than of controls. There was no significant difference in MD along the UF between the two groups. Intraobserver reliability (intraclass correlation coefficient) for the first and second measurement was r > 0.93 for measured FA and r > 0.92 for measured MD.
Our results suggest that FA reflects progression of AD-related histopathological changes in the UF of the white matter and may represent a useful biological index in monitoring AD. Diffusion tensor tract-specific analysis with voxelized tract shape processing to measure the core of the tract may be a sensitive tool for evaluation of diffusion abnormalities of white matter tracts in AD.
我们的目的是通过使用一种测量束核心的新方法——扩散张量纤维束成像（DTT），来确定阿尔茨海默病（AD）患者钩束（UF）的扩散异常情况。
我们研究了19例AD患者和19例年龄匹配的对照受试者，他们均接受了使用扩散张量成像（DTI）的磁共振成像（MRI）检查。生成了UF的DTT。在对束形状进行体素化处理后，测量了束核心的平均扩散率（MD）和分数各向异性（FA）。采用学生t检验比较AD患者和对照组的结果。还进行了观察者内相关性测试。
AD患者UF的FA显著低于对照组（P < 0.0001）。两组之间沿UF的MD无显著差异。对于测量的FA，第一次和第二次测量的观察者内可靠性（组内相关系数）r > 0.93，对于测量的MD，r > 0.92。
我们的结果表明，FA反映了AD相关组织病理学变化在白质UF中的进展，可能是监测AD的一个有用的生物学指标。采用体素化束形状处理进行扩散张量束特异性分析以测量束核心，可能是评估AD中白质束扩散异常的一种敏感工具。
