Intrinsic signal changes accompanying sensory stimulation: functional brain mapping with magnetic resonance imaging.

作者：Satoshi Ogawa, David W. Tank, Ravi S. Menon, Jutta Ellermann, Seong‐Gi Kim, Hellmut Merkle, Kǎmil Uǧurbil · 发表于：Proceedings of the National Academy of Sciences · 年份：1992 · DOI：10.1073/pnas.89.13.5951 · 被引用次数：3740 · 研究领域：Advanced MRI Techniques and Applications、Atomic and Subatomic Physics Research、Functional Brain Connectivity Studies

We report that visual stimulation produces an easily detectable (5-20%) transient increase in the intensity of water proton magnetic resonance signals in human primary visual cortex in gradient echo images at 4-T magnetic-field strength. The observed changes predominantly occur in areas containing gray matter and can be used to produce high-spatial-resolution functional brain maps in humans. Reducing the image-acquisition echo time from 40 msec to 8 msec reduces the amplitude of the fractional signal change, suggesting that it is produced by a change in apparent transverse relaxation time T*2. The amplitude, sign, and echo-time dependence of these intrinsic signal changes are consistent with the idea that neural activation increases regional cerebral blood flow and concomitantly increases venous-blood oxygenation.