Whole-brain histogram and voxel-based analyses of diffusion tensor imaging in patients with leukoaraiosis: Correlation with motor and cognitive impairment
Whole-brain histogram and voxel-based analyses of diffusion tensor imaging in patients with leukoaraiosis: Correlation with motor and cognitive impairment
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DOI：
10.3174/ajnr.a0555
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发表时间：
2007-08-01
影响因子：
3.5
通讯作者：
Mascalchi, M.
中科院分区：
文献类型：
--
作者：
Della Nave, R.;Foresti, S.;Mascalchi, M.
背景和目的：脑白质变化，称为脑白质疏松症（LA），在 T2 加权 MR 图像中表现为信号强度增加的区域，在老年受试者中很常见，但 LA 与认知或运动缺陷之间可能的相关性尚未确定。我们假设，对通过扩散张量成像 (DTI) 计算的全脑平均扩散率 (MD) 和分数各向异性 (FA) 图进行直方图和基于体素的分析可能是比视觉量表更敏感的工具，可用于研究 LA 的临床相关性。 材料和方法：使用液体衰减对 36 名脑白质疏松和残疾研究的患者进行了评估 LA 扩展的反转恢复、体积的 T1 加权图像以及 MD 和 FA 的 DTI。 LA 的范围通过目视评定。计算归一化的总脑容量、灰质脑容量和白质脑容量，以及全脑 MID 和 FA 图的第 25 个百分位、第 50 个百分位、峰度和偏度。最后，使用 SPM2 软件对灰质和白质体积、MID 和 FA 图进行基于体素的分析。使用 Spearman 等级检验和 SPM2 软件进行视觉或计算机数据与运动或神经心理学量表评分之间的相关性分析。结果：视觉评分与一些 MD 和 FA 直方图指标相关 (P < .01)。然而，只有 MID 和 FA 直方图的第 25 个和第 50 个百分位数、峰度和偏度与运动或神经心理缺陷相关。基于体素的分析揭示了胼胝体中大量增加的 MID 与胼胝周白质和运动缺陷之间的相关性（多重比较校正后 P < 0.05）。 结论：这些结果与以下假设一致：全脑 MID 和 FA 图的直方图和基于体素的分析是比 LA 患者临床相关性视觉评估更敏感的工具。
BACKGROUND AND PURPOSE: Cerebral white matter changes, termed leukoaraiosis (LA), appearing as areas of increased signal intensity in T2-weighted MR images, are common in elderly subjects, but the possible correlation of LA with cognitive or motor deficit has not been established. We hypothesized that histogram and voxel-based analyses of whole-brain mean diffusivity (MD) and fractional anisotropy (FA) maps calculated from diffusion tensor imaging (DTI) could be more sensitive tools than visual scales to investigate the clinical correlates of LA.MATERIALS AND METHODS: Thirty-six patients of the Leukoaraiosis and Disability Study were evaluated with fluid-attenuated inversion recovery for LA extension, T1-weighted images for volume, and DTI for MD and FA. The extent of LA was rated visually. The normalized total, gray, and white matter brain volumes were computed, as well as the 25th percentile, 50th percentile, kurtosis, and skewness of the MID and FA maps of the whole brain. Finally, voxel-based analysis on the maps of gray and white matter volume, MID, and FA was performed with SPM2 software. Correlation analyses between visual or computerized data and motor or neuropsychologic scale scores were performed using the Spearman rank test and the SPM2 software.RESULTS: The visual score correlated with some MD and FA histogram metrics (P < .01). However, only the 25th and 50th percentiles, kurtosis, and skewness of the MID and FA histograms correlated with motor or neuropsychologic deficits. Voxel-based analysis revealed a correlation (P < .05 corrected for multiple comparisons) between a large cluster of increased MID in the corpus callosunn and pericallosal white matter and motor deficit.CONCLUSIONS: These results are consistent with the hypothesis that histogram and voxel-based analyses of the whole-brain MID and FA maps are more sensitive tools than the visual evaluation for clinical correlation in patients with LA.