Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.
Adult Neurodevelopment and Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.
J Neuroimaging. 2019 Nov;29(6):721-729. doi: 10.1111/jon.12646. Epub 2019 Jul 3.
Amyloid deposition, tau neurofibrillary tangles, and cerebrovascular dysfunction are important pathophysiologic features in Alzheimer's disease. Pittsburgh compound B ([ C]-PIB) is a positron emission tomography (PET) radiotracer used to quantify amyloid deposition in vivo. In addition, certain models of [ C]-PIB delivery reflect cerebral blood flow rather than amyloid plaques. As cerebral blood flow and perfusion deficits are associated with white matter pathology, we hypothesized that [ C]-PIB delivery in white matter regions may reflect white matter integrity.
We obtained [ C]-PIB-PET scans and quantified white matter hyperintensities and global fractional anisotropy on magnetic resonance images as biomarkers of white matter pathology in 34 older participants with mild cognitive impairment with or without a history of major depressive disorder. We analyzed the [ C]-PIB time-activity curve data with models associated with cerebral blood flow: the early maximum standard uptake value and the relative delivery parameter R1. We used a global white matter region of interest.
Both of the partial-volume corrected PET parameters were correlated with white matter hyperintensities and fractional anisotropy.
Future studies are warranted to explore whether [ C]-PIB PET is a "triple biomarker" that may provide information about amyloid deposition, cerebral blood flow, and white matter pathology.
淀粉样蛋白沉积、tau 神经原纤维缠结和脑血管功能障碍是阿尔茨海默病的重要病理生理特征。匹兹堡化合物 B([C]-PIB)是一种正电子发射断层扫描(PET)示踪剂，用于在体内定量检测淀粉样蛋白沉积。此外，某些[C]-PIB 传递模型反映了脑血流，而不是淀粉样斑块。由于脑血流和灌注缺陷与白质病理学有关，我们假设白质区域的[C]-PIB 传递可能反映白质完整性。
我们在 34 名伴有或不伴有重度抑郁症病史的轻度认知障碍老年患者中获得了[C]-PIB-PET 扫描，并对磁共振图像上的白质高信号和整体各向异性分数进行了量化，作为白质病理学的生物标志物。我们使用与脑血流相关的模型来分析[C]-PIB 时间-活性曲线数据：早期最大标准摄取值和相对传递参数 R1。我们使用了一个全脑白质感兴趣区。
两种部分容积校正的 PET 参数均与白质高信号和各向异性分数相关。
未来的研究需要探索[C]-PIB PET 是否是一种“三重生物标志物”，它可以提供关于淀粉样蛋白沉积、脑血流和白质病理学的信息。
