Ogawa S, Lee T M, Kay A R, Tank D W
Biophysics Research Department, AT&T Bell Laboratories, Murray Hill, NJ 07974.
Proc Natl Acad Sci U S A. 1990 Dec;87(24):9868-72. doi: 10.1073/pnas.87.24.9868.
Paramagnetic deoxyhemoglobin in venous blood is a naturally occurring contrast agent for magnetic resonance imaging (MRI). By accentuating the effects of this agent through the use of gradient-echo techniques in high fields, we demonstrate in vivo images of brain microvasculature with image contrast reflecting the blood oxygen level. This blood oxygenation level-dependent (BOLD) contrast follows blood oxygen changes induced by anesthetics, by insulin-induced hypoglycemia, and by inhaled gas mixtures that alter metabolic demand or blood flow. The results suggest that BOLD contrast can be used to provide in vivo real-time maps of blood oxygenation in the brain under normal physiological conditions. BOLD contrast adds an additional feature to magnetic resonance imaging and complements other techniques that are attempting to provide positron emission tomography-like measurements related to regional neural activity.
静脉血中的顺磁性脱氧血红蛋白是一种天然存在的磁共振成像（MRI）造影剂。通过在高场中使用梯度回波技术增强这种造影剂的效果，我们展示了脑微血管系统的体内图像，其图像对比度反映了血氧水平。这种血氧水平依赖（BOLD）对比度随麻醉剂、胰岛素诱导的低血糖以及改变代谢需求或血流的吸入气体混合物所引起的血氧变化而变化。结果表明，BOLD对比度可用于在正常生理条件下提供脑内血氧合的体内实时图谱。BOLD对比度为磁共振成像增添了一个额外的特性，并补充了其他试图提供与区域神经活动相关的正电子发射断层扫描样测量的技术。
