Ogawa S, Lee T M, Barrere B
AT&T Bell Laboratories, Murray Hill, NJ 07974.
Magn Reson Med. 1993 Feb;29(2):205-10. doi: 10.1002/mrm.1910290208.
The sensitivity of magnetic resonance image signals of the brain to the change in the cerebral blood oxygenation was measured in gradient echo images of rat brains at a field strength of 7 T. The sensitivity depended on the blood vessel volume relative to the tissue volume within the image voxel, and signal intensities in the cortical area were well correlated with the change in the venous blood de-oxygenation level at the sagittal sinus. Tissue signals in the image (15 ms echo time) showed a sensitivity of 10-20% change for the full range of deoxygenation level from 0-100%. From these observations and image simulations, the extent of the signal response to some neuro-stimulation which induces an increase in regional cerebral blood flow has been estimated for 4 T field strength.
在7T场强下，通过大鼠脑的梯度回波图像测量了脑磁共振图像信号对脑血氧合变化的敏感性。该敏感性取决于图像体素内血管体积与组织体积的相对关系，并且皮质区域的信号强度与矢状窦处静脉血脱氧水平的变化密切相关。图像（回波时间15ms）中的组织信号在0%-100%的脱氧水平全范围内显示出10%-20%变化的敏感性。基于这些观察结果和图像模拟，已经估算了在4T场强下对某些诱导局部脑血流增加的神经刺激的信号响应程度。
