Department of Radiology, China-Japan Friendship Hospital, Beijing 100029, PR China; Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PR China.
Department of Biomedical Engineering, Cornell University, Ithaca, New York 14853, USA; Department of Radiology, Weill Cornell Medical College, New York, New York 10065, USA.
Neuroimage. 2023 Nov 15;282:120381. doi: 10.1016/j.neuroimage.2023.120381. Epub 2023 Sep 19.
The objective of this study was to evaluate the whole-brain pattern of oxygen extraction fraction (OEF), cerebral blood flow (CBF), and cerebral metabolic rate of oxygen consumption (CMRO) perturbation in Alzheimer's disease (AD) and investigate the relationship between regional cerebral oxygen metabolism and global cognition.
Twenty-six AD patients and 25 age-matched healthy controls (HC) were prospectively recruited in this study. Mini-Mental State Examination (MMSE) was used to evaluate cognitive status. We applied the QQ-CCTV algorithm which combines quantitative susceptibility mapping and quantitative blood oxygen level-dependent models (QQ) for OEF calculation. CBF map was computed from arterial spin labeling and CMRO was generated based on Fick's principle. Whole-brain and regional OEF, CBF, and CMRO analyses were performed. The associations between these measures in substructures of deep brain gray matter and MMSE scores were assessed.
Whole brain voxel-wise analysis showed that CBF and CMRO values significantly decreased in AD predominantly in the bilateral angular gyrus, precuneus gyrus and parieto-temporal regions. Regional analysis showed that CBF value decreased in the bilateral caudal hippocampus and left rostral hippocampus and CMRO value decreased in left caudal and rostral hippocampus in AD patients. Considering all subjects in the AD and HC groups combined, the mean CBF and CMRO values in the bilateral hippocampus positively correlated with the MMSE score.
CMRO mapping with the QQ-CCTV method - which is readily available in MR systems for clinical practice - can be a potential biomarker for AD. In addition, CMRO in the hippocampus may be a useful tool for monitoring cognitive impairment.
本研究旨在评估阿尔茨海默病（AD）患者全脑氧摄取分数（OEF）、脑血流（CBF）和脑氧代谢率（CMRO）的整体变化模式，并探讨局部脑氧代谢与整体认知功能的关系。
本研究前瞻性纳入 26 例 AD 患者和 25 名年龄匹配的健康对照者（HC）。采用简易精神状态检查量表（MMSE）评估认知状态。我们应用结合定量磁化率图和定量血氧水平依赖模型（QQ）的 QQ-CCTV 算法计算 OEF。通过动脉自旋标记法获得 CBF 图，根据 Fick 原理生成 CMRO。进行全脑和局部 OEF、CBF 和 CMRO 分析。评估深部灰质脑结构亚区这些测量值与 MMSE 评分之间的相关性。
全脑体素分析显示，AD 患者全脑 CBF 和 CMRO 值均显著降低，主要位于双侧角回、楔前叶和顶颞叶区域。局部分析显示，AD 患者双侧海马尾部和左侧海马头侧 CBF 值降低，左侧海马尾部和头侧 CMRO 值降低。考虑到 AD 和 HC 组所有受试者，双侧海马的平均 CBF 和 CMRO 值与 MMSE 评分呈正相关。
基于 QQ-CCTV 方法的 CMRO 图可作为 AD 的潜在生物标志物，该方法在临床实践中的 MR 系统中易于获得。此外，海马 CMRO 可能是监测认知障碍的有用工具。
