Jain Varsha, Langham Michael C, Wehrli Felix W
Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania 19104, USA.
J Cereb Blood Flow Metab. 2010 Sep;30(9):1598-607. doi: 10.1038/jcbfm.2010.49. Epub 2010 Apr 21.
Measuring the global cerebral metabolic rate of oxygen (CMRO(2)) is a valuable tool for assessing brain vitality and function. Measurement of blood oxygen saturation (HbO(2)) and flow in the major cerebral outflow and inflow vessels can provide a global estimate of CMRO(2). We demonstrate a rapid noninvasive method for quantifying CMRO(2) by simultaneously measuring venous oxygen saturation in the superior sagittal sinus with magnetic resonance susceptometry-based oximetry, a technique that exploits the intrinsic susceptibility of deoxygenated hemoglobin, and the average blood inflow rate with phase-contrast magnetic resonance imaging. The average venous HbO(2), cerebral blood flow, and global CMRO(2) values in eight healthy, normal study subjects were 64%+/-4%, 45.2+/-3.2 mL per 100 g per minute, and 127+/-7 micromol per 100 g per minute, respectively. These values are in good agreement with those reported in literature. The technique described is noninvasive, robust, and reproducible for in vivo applications, making it ideal for use in clinical settings for assessing the pathologies associated with dysregulation of cerebral metabolism. In addition, the short acquisition time (approximately 30 seconds) makes the technique suitable for studying the temporal variations in CMRO(2) in response to physiologic challenges.
测量全脑氧代谢率（CMRO₂）是评估脑活力和功能的一项重要手段。测量主要脑流出和流入血管中的血氧饱和度（HbO₂）及血流，可对CMRO₂进行整体估算。我们展示了一种快速无创的CMRO₂定量方法，该方法通过基于磁共振磁化率测定法的血氧测定法同步测量上矢状窦中的静脉血氧饱和度（该技术利用了脱氧血红蛋白的固有磁化率），并结合相位对比磁共振成像测量平均血流率。8名健康正常研究对象的平均静脉HbO₂、脑血流量和全脑CMRO₂值分别为64%±4%、每100克每分钟45.2±3.2毫升和每100克每分钟127±7微摩尔。这些值与文献报道的值高度一致。所描述的技术具有无创、稳健且可在体内重复应用的特点，使其非常适合在临床环境中用于评估与脑代谢失调相关的病理情况。此外，短采集时间（约30秒）使该技术适用于研究CMRO₂对生理刺激的时间变化。
