Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, CA, 90292, USA.
Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, CA, 90292, USA; Stanford University, Stanford, CA, 94305, USA.
Neuroimage. 2020 Feb 1;206:116327. doi: 10.1016/j.neuroimage.2019.116327. Epub 2019 Nov 1.
White matter hyperintensities (WMHs) are brain white matter lesions that are hyperintense on fluid attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) scans. Larger WMH volumes have been associated with Alzheimer's disease (AD) and with cognitive decline. However, the relationship between WMH volumes and cross-sectional cognitive measures has been inconsistent. We hypothesize that this inconsistency may arise from 1) the presence of AD-specific neuropathology that may obscure any WMH effects on cognition, and 2) varying criteria for creating a WMH segmentation. Manual and automated programs are typically used to determine segmentation boundaries, but criteria for those boundaries can differ. It remains unclear whether WMH volumes are associated with cognitive deficits, and which segmentation criteria influence the relationships between WMH volumes and clinical outcomes. In a sample of 260 non-demented participants (ages 55-90, 141 males, 119 females) from the Alzheimer's Disease Neuroimaging Initiative (ADNI), we compared the performance of five WMH segmentation methods, by relating the WMH volumes derived using each method to both clinical diagnosis and composite measures of executive function and memory. To separate WMH effects on cognition from effects related to AD-specific processes, we performed analyses separately in people with and without abnormal cerebrospinal fluid amyloid levels. WMH volume estimates that excluded more diffuse, lower-intensity lesions were more strongly correlated with clinical diagnosis and cognitive performance, and only in those without abnormal amyloid levels. These findings may inform best practices for WMH segmentation, and suggest that AD neuropathology may mask WMH effects on clinical diagnosis and cognition.
脑白质高信号（WMHs）是在液体衰减反转恢复（FLAIR）磁共振成像（MRI）扫描上呈高信号的脑白质病变。较大的 WMH 体积与阿尔茨海默病（AD）和认知能力下降有关。然而，WMH 体积与横断面认知测量之间的关系一直不一致。我们假设这种不一致可能源于：1）存在 AD 特异性神经病理学，可能掩盖任何 WMH 对认知的影响；2）WMH 分割的标准不同。手动和自动程序通常用于确定分割边界，但这些边界的标准可能不同。WMH 体积是否与认知缺陷相关，以及哪些分割标准影响 WMH 体积与临床结局之间的关系仍不清楚。在来自阿尔茨海默病神经影像学倡议（ADNI）的 260 名非痴呆参与者（年龄 55-90 岁，141 名男性，119 名女性）的样本中，我们比较了五种 WMH 分割方法的性能，通过将每种方法得出的 WMH 体积与临床诊断和执行功能和记忆的综合测量相关联来比较。为了将 WMH 对认知的影响与与 AD 特异性过程相关的影响分开，我们在有和没有异常脑脊液淀粉样蛋白水平的人群中分别进行了分析。排除更弥散、强度更低的病变的 WMH 体积估计值与临床诊断和认知表现的相关性更强，而且仅在没有异常淀粉样蛋白水平的人群中。这些发现可能为 WMH 分割提供最佳实践，并表明 AD 神经病理学可能掩盖 WMH 对临床诊断和认知的影响。
