Localized NMR spectroscopy and functional mapping of the brain.

局部质子磁共振波谱（1H-MRS）和激光多普勒血流仪（LDF）的同时应用，使我们能够观察局部乳酸水平和局部血流量（rBF）在麻醉兔脑的同时变化。1H-MRS的体素（8 mm立方）主要位于丘脑区，rBF记录在对侧丘脑区。通过使用体模模型评估1H-MRS中的定位，并证明实际上是令人满意的。缺氧时乳酸逐渐增加，rBF迅速增加。尽管rBF增加，但氧输送（即动脉血中的氧含量（O2 CT）乘以rBF）减少。缺氧30 min后10 min乳酸升高与缺氧时氧供不足呈直线相关（r ~ 2 =0.68，n=14，P<0.001）。在随后的恢复期，rBF缓慢下降，而O2 CT迅速回升至对照水平。缺氧后rFB的恢复率与乳酸的增加呈线性相关（偏相关系数; r2=0.72，n=14，p<0.001）。

Simultaneous applications of localized proton magnetic resonance spectroscopy (1H-MRS) and laser doppler flowmetry (LDF) allowed us to observe concurrent changes in regional lactate level and regional blood flow (rBF) in the anesthetized rabbit brain. The voxel (8mm-cubic) for 1H-MRS was located mostly in the thalamic area, and the rBF was recorded in the same area contralaterally. The localization in the 1H-MRS was assessed by using a phantom model and was proved to be practically satisfactory. During hypoxia, lactate increased gradually, while the rBF increased rapidly. Despite the increase in rBF,the oxygen delivery, which was the oxygen content in arterial blood (O2 CT) multiplied by the rBF,decreased. There was a linear correlation between the increase in lactate in last ten minutes during the thirty minutes hypoxia and deficiency in the oxygen delivery during hypoxia (correlation coefficience ; r2=0.68, n=14, P<0.001). In the subsequent recovery period, the rBF decreased slowly, while the O2 CT increased rapidly back to the control level. This rate of rFB recovery after hypoxia was linearly correlated with the increase in lactate (partial correlation coefficience ; r2=0.72, n=14, p<0.001).