Guo Hui, Siu William, D'Arcy Ryan Cn, Black Sandra E, Grajauskas Lukas A, Singh Sonia, Zhang Yunting, Rockwood Kenneth, Song Xiaowei
Health Sciences and Innovation, ImageTech Laboratory, Fraser Health Authority, Surrey, BC, Canada.
Department of Diagnostic Imaging, Tianjin Medical University General Hospital, Tianjin, China.
Clin Interv Aging. 2017 Aug 9;12:1251-1270. doi: 10.2147/CIA.S139515. eCollection 2017.
One of the central features of brain aging is the accumulation of multiple age-related structural changes, which occur heterogeneously in individuals and can have immediate or potential clinical consequences. Each of these deficits can coexist and interact, producing both independent and additive impacts on brain health. Many of the changes can be visualized using MRI. To collectively assess whole-brain structural changes, the MRI-based Brain Atrophy and Lesion Index (BALI) has been developed. In this study, we validate this whole-brain health assessment approach using several clinical MRI examinations.
Data came from three independent studies: the Alzheimer's Disease Neuroimaging Initiative Phase II (n=950; women =47.9%; age =72.7±7.4 years); the National Alzheimer's Coordinating Center (n=722; women =55.1%; age =72.7±9.9 years); and the Tianjin Medical University General Hospital Research database on older adults (n=170; women =60.0%; age =62.9±9.3 years). The 3.0-Tesla MRI scans were evaluated using the BALI rating scheme on the basis of T1-weighted (T1WI), T2-weighted (T2WI), T2-weighted fluid-attenuated inversion recovery (T2-FLAIR), and T2*-weighted gradient-recalled echo (T2*GRE) images.
Atrophy and lesion changes were commonly seen in each MRI test. The BALI scores based on different sequences were highly correlated (Spearman >0.69; <0.00001). They were associated with age (>0.29; <0.00001) and differed by cognitive status (>26.48, <0.00001). T2-FLAIR revealed a greater level of periventricular (=29.09) and deep white matter (=26.65, <0.001) lesions than others, but missed revealing certain dilated perivascular spaces that were seen in T2WI (<0.001). Microhemorrhages occurred in 15.3% of the sample examined and were detected using only T2*GRE.
The T1WI- and T2WI-based BALI evaluations consistently identified the burden of aging and dementia-related decline of structural brain health. Inclusion of additional MRI tests increased lesion differentiation. Further research is to integrate MRI tests for a clinical tool to aid the diagnosis and intervention of brain aging.
脑老化的核心特征之一是多种与年龄相关的结构变化的积累，这些变化在个体中异质性发生，可能产生直接或潜在的临床后果。这些缺陷中的每一个都可能共存并相互作用，对脑健康产生独立和累加的影响。许多变化可以通过磁共振成像（MRI）可视化。为了综合评估全脑结构变化，基于MRI的脑萎缩和病变指数（BALI）已被开发出来。在本研究中，我们使用几种临床MRI检查来验证这种全脑健康评估方法。
数据来自三项独立研究：阿尔茨海默病神经影像学倡议二期（n = 950；女性 = 47.9%；年龄 = 72.7±7.4岁）；国家阿尔茨海默病协调中心（n = 722；女性 = 55.1%；年龄 = 72.7±9.9岁）；以及天津医科大学总医院老年成人研究数据库（n = 170；女性 = 60.0%；年龄 = 62.9±9.3岁）。基于T1加权（T1WI）、T2加权（T2WI）、T2加权液体衰减反转恢复（T2-FLAIR）和T2加权梯度回波（T2GRE）图像，使用BALI评分方案对3.0特斯拉MRI扫描进行评估。
在每次MRI检查中，萎缩和病变变化都很常见。基于不同序列的BALI评分高度相关（斯皮尔曼相关系数>0.69；P<0.00001）。它们与年龄相关（相关系数>0.29；P<0.00001），并且在认知状态方面存在差异（差异>26.48，P<0.00001）。T2-FLAIR显示出比其他序列更高水平的脑室周围病变（P = 29.09）和深部白质病变（P = 26.65，P<0.001），但遗漏了在T2WI中可见的某些扩张的血管周围间隙（P<0.001）。在所检查的样本中，15.3%出现微出血，且仅使用T2*GRE检测到。
基于T1WI和T2WI的BALI评估一致地识别出与衰老和痴呆相关的脑结构健康下降的负担。纳入额外的MRI检查增加了病变的区分度。进一步的研究是将MRI检查整合为一种临床工具，以辅助脑老化的诊断和干预。
