Superior sagittal sinus flow as a proxy for tracking global cerebral blood flow dynamics during wakefulness and sleep.
Superior sagittal sinus flow as a proxy for tracking global cerebral blood flow dynamics during wakefulness and sleep.
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DOI：
10.1177/0271678x231164423
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发表时间：
2023-08
期刊：
影响因子：
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通讯作者：
Wehrli FW
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作者：
Caporale AS;Barclay AM;Xu J;Rao H;Lee H;Langham MC;Detre JA;Wehrli FW
睡眠是一种意识减退的状态，会影响脑氧代谢，降低脑氧代谢率(CMRO2)。此前，我们根据Fick的原理对睡眠中的CMRO2进行了量化，用单波段MRI序列测量了血红蛋白O2饱和度(SvO2)和上矢状窦(SSS)的血流量，并将其放大以获得总脑血流量(TCBF)。该程序包括简短的初始校准扫描，以确定假设状态不变的升标因数(FC)。在这里，我们使用双波段序列，每16秒同时提供SSS的SvO2和颈部的tCBF，允许动态定量FC。对10名健康受试者进行了80分钟的MRI扫描和脑电同步扫描，每个受试者产生300个时间图像帧。根据美国睡眠医学学会的标准，四名志愿者获得了慢波睡眠，δ波活动增加就是明证。SWS维持13.5 ± 7.0min，CMRO228.6 ± 较睡前下降5.5%。重要的是，通过上调SSS-血流获得的tCBF与直接在颈部流入动脉测量的tCBF之间的偏差可以忽略不计(类内相关系数0.95 ± 0.04，在所有受试者中平均)，表明单波段方法是量化tCBF的有效替代方法，在不影响准确性的情况下简化了图像数据的收集和分析。
Sleep, a state of reduced consciousness, affects brain oxygen metabolism and lowers cerebral metabolic rate of oxygen (CMRO2). Previously, we quantified CMRO2 during sleep via Fick’s Principle, with a single-band MRI sequence measuring both hemoglobin O2 saturation (SvO2) and superior sagittal sinus (SSS) blood flow, which was upscaled to obtain total cerebral blood flow (tCBF). The procedure involves a brief initial calibration scan to determine the upscaling factor (fc), assumed state-invariant. Here, we used a dual-band sequence to simultaneously provide SvO2 in SSS and tCBF in the neck every 16 seconds, allowing quantification of fc dynamically. Ten healthy subjects were scanned by MRI with simultaneous EEG for 80 minutes, yielding 300 temporal image frames per subject. Four volunteers achieved slow-wave sleep (SWS), as evidenced by increased δ-wave activity (per American Academy of Sleep Medicine criteria). SWS was maintained for 13.5 ± 7.0 minutes, with CMRO2 28.6 ± 5.5% lower than pre-sleep wakefulness. Importantly, there was negligible bias between tCBF obtained by upscaling SSS-blood flow, and tCBF measured directly in the inflowing arteries of the neck (intra-class correlation 0.95 ± 0.04, averaged across all subjects), showing that the single-band approach is a valid substitute for quantifying tCBF, simplifying image data collection and analysis without sacrificing accuracy.