Wierenga Christina E, Hays Chelsea C, Zlatar Zvinka Z
VA San Diego Healthcare System, San Diego, CA, USA Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA.
VA San Diego Healthcare System, San Diego, CA, USA.
J Alzheimers Dis. 2014;42 Suppl 4(Suppl 4):S411-9. doi: 10.3233/JAD-141467.
There is growing recognition that cerebral hypoperfusion is related to the pathogenesis of Alzheimer's disease (AD), implicating the measurement of cerebral blood flow (CBF) as a possible biomarker of AD. The ability to identify the earliest and most reliable markers of incipient cognitive decline and clinical symptoms is critical to develop effective preventive strategies and interventions for AD. Arterial spin labeling (ASL) magnetic resonance imaging (MRI) measures CBF by magnetically labeling arterial water and using it as an endogenous tracer. Studies using ASL MRI in humans indicate that CBF changes are present several years before the development of the clinical symptoms of AD. Moreover, ASL-measured CBF has been shown to distinguish between cognitively normal individuals, adults at risk for AD, and persons diagnosed with AD. Some studies indicate that CBF may even be sensitive for predicting cognitive decline and conversion to mild cognitive impairment and AD over time. Taken together, evidence suggests that the current staging models of AD biomarker pathology should incorporate early changes in CBF as a useful biomarker, possibly present even earlier than amyloid-β accumulation. Though still a research tool, ASL imaging is a promising non-invasive and reliable method with the potential to serve as a future clinical tool for the measurement of CBF in preclinical AD.
越来越多的人认识到脑灌注不足与阿尔茨海默病（AD）的发病机制有关，这意味着测量脑血流量（CBF）可能是AD的一种生物标志物。识别早期认知衰退和临床症状的最早且最可靠标志物的能力对于制定有效的AD预防策略和干预措施至关重要。动脉自旋标记（ASL）磁共振成像（MRI）通过对动脉血中的水进行磁性标记并将其用作内源性示踪剂来测量CBF。在人体中使用ASL MRI的研究表明，在AD临床症状出现前数年，CBF就已发生变化。此外，经ASL测量的CBF已被证明能够区分认知正常个体、有患AD风险的成年人以及被诊断为AD的患者。一些研究表明，随着时间的推移，CBF甚至可能对预测认知衰退以及向轻度认知障碍和AD的转化具有敏感性。综上所述，有证据表明，目前AD生物标志物病理学的分期模型应将CBF的早期变化纳入其中，作为一种有用的生物标志物，其出现可能比淀粉样β蛋白积累还要早。尽管ASL成像仍是一种研究工具，但它是一种有前景的非侵入性且可靠的方法，有可能成为未来在临床前AD中测量CBF的临床工具。
