Lundervold A, Ersland L, Gjesdal K I, Smievoll A I, Tillung T, Sundberg H, Hugdahl K
Department of Physiology, University of Bergen, Norway.
Int J Neurosci. 1995 Apr;81(3-4):151-68. doi: 10.3109/00207459509004883.
Recent advances in functional magnetic resonance imaging (fMRI) at > or = 1.5 T magnetic field strength and with high speed single-shot echo planar imaging techniques have made it possible to monitor local changes in cerebral blood volume, cerebral blood flow, and blood oxygenation level in response to sensory stimulation, simple motor activity, and possibly also to more complex cognitive processing. However, fMRI has also been accomplished on conventional MR scanners of medium field strength (approximately 1.0 T) using special pulse sequences and appropriate methods for image analysis. We present results from six subjects on photic stimulation using a standard 1.0 T MR scanner together with special software for off-line image analysis. Continuous serial T2-weighted imaging were performed for 6 minutes in the plane of the calcarine fissure. There were 3 repetitions of 1 minute resting state of darkness (OFF) and 1 minute activated state (ON) with 8 Hz flicker stimulation. To directly map these functional images to the underlying anatomy we also acquired a high resolution T1-weighted image from the same axial slice. The results demonstrated that stimulus-related signals can be obtained from primary visual cortex with a conventional 1.0 T MR scanner. Further methodological improvements are discussed and related to present and future possibilities for the use of fMRI within psychophysiology.
近期，在磁场强度≥1.5T且采用高速单次激发回波平面成像技术的功能磁共振成像（fMRI）方面取得的进展，使得监测因感觉刺激、简单运动活动以及可能更复杂的认知加工而引起的脑血容量、脑血流量和血氧水平的局部变化成为可能。然而，使用特殊脉冲序列和适当的图像分析方法，在中等场强（约1.0T）的传统磁共振扫描仪上也已实现功能磁共振成像。我们展示了6名受试者使用标准1.0T磁共振扫描仪进行光刺激的结果，以及用于离线图像分析的特殊软件。在距状裂平面连续进行6分钟的系列T2加权成像。黑暗（关闭）休息状态1分钟和8Hz闪烁刺激激活状态（开启）1分钟的过程重复3次。为了将这些功能图像直接映射到其下方的解剖结构，我们还从同一轴位切片获取了高分辨率T1加权图像。结果表明，使用传统1.0T磁共振扫描仪可从初级视觉皮层获得与刺激相关的信号。文中讨论了进一步的方法学改进，并将其与功能磁共振成像在心理生理学中的当前及未来应用可能性相关联。
