Barhoum Suliman, Langham Michael C, Magland Jeremy F, Rodgers Zachary B, Li Cheng, Rajapakse Chamith S, Wehrli Felix W
Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
J Cereb Blood Flow Metab. 2015 Oct;35(10):1616-22. doi: 10.1038/jcbfm.2015.96. Epub 2015 May 13.
A recently reported quantitative magnetic resonance imaging (MRI) method denoted OxFlow has been shown to be able to quantify whole-brain cerebral metabolic rate of oxygen (CMRO2) by simultaneously measuring oxygen saturation (SvO2) in the superior sagittal sinus and cerebral blood flow (CBF) in the arteries feeding the brain in 30 seconds, which is adequate for measurement at baseline but not necessarily in response to neuronal activation. Here, we present an accelerated version of the method (referred to as F-OxFlow) that quantifies CMRO2 in 8 seconds scan time under full retention of the parent method's capabilities and compared it with its predecessor at baseline in 10 healthy subjects. Results indicate excellent agreement between both sequences, with mean bias of 2.2% (P=0.18, two-tailed t-test), 3.4% (P=0.08, two-tailed t-test), and 2.0% (P=0.56, two-tailed t-test) for SvO2, CBF, and CMRO2, respectively. F-OxFlow's potential to monitor dynamic changes in SvO2, CBF, and CMRO2 is illustrated in a paradigm of volitional apnea applied to five of the study subjects. The sequence captured an average increase in SvO2, CBF, and CMRO2 of 10.1±2.5%, 43.2±9.2%, and 7.1±2.2%, respectively, in good agreement with literature values. The method may therefore be suited for monitoring alterations in CBF and SvO2 in response to neurovascular stimuli.
最近报道的一种定量磁共振成像（MRI）方法，称为氧流（OxFlow），已被证明能够在30秒内通过同时测量上矢状窦中的氧饱和度（SvO2）和供应大脑的动脉中的脑血流量（CBF）来量化全脑脑氧代谢率（CMRO2），这对于基线测量是足够的，但不一定适用于对神经元激活的反应。在此，我们提出了该方法的加速版本（称为F-OxFlow），它在完全保留母方法功能的情况下，在8秒的扫描时间内量化CMRO2，并在10名健康受试者的基线状态下将其与其前身进行比较。结果表明，两个序列之间具有极好的一致性，SvO2、CBF和CMRO2的平均偏差分别为2.2%（P = 0.18，双尾t检验）、3.4%（P = 0.08，双尾t检验）和2.0%（P = 0.56，双尾t检验）。F-OxFlow监测SvO2、CBF和CMRO2动态变化的潜力在应用于5名研究对象的自主呼吸暂停范例中得到了说明。该序列分别捕捉到SvO2、CBF和CMRO2的平均增加量为10.1±2.5%、43.2±9.2%和7.1±2.2%，与文献值高度一致。因此，该方法可能适用于监测因神经血管刺激而引起的CBF和SvO2变化。
