Cho Z H, Chung S C, Lim D W, Wong E K
Department of Radiological Sciences, University of California, Irvine 92717, USA.
Magn Reson Med. 1998 Feb;39(2):331-5. doi: 10.1002/mrm.1910390224.
MR acoustic, or sound, noise due to gradient pulsing has been one of the problems in MRI, both in patient scanning as well as in many areas of psychiatric and neuroscience research, such as brain fMRI. Especially in brain fMRI, sound noise is one of the serious noise sources that obscures the small signals obtainable from the subtle changes occurring in oxygenation status in the cortex and blood capillaries. Therefore, we have studied the effects of acoustic, or sound, noise arising in fMR imaging of the auditory, motor, and visual cortices. The results show that the effects of acoustic noise on motor and visual responses are opposite. That is, for motor activity, there is an increased total motor activation, whereas for visual stimulation, the corresponding (visual) cortical activity is diminished substantially when the subject is exposed to a loud acoustic sound. Although the current observations are preliminary and require more experimental confirmation, it seems that the observed acoustic-noise effects on brain functions, such as in the motor and visual cortices, are new observations and could have significant consequences in data observation and interpretation in future fMRI studies.
由于梯度脉冲产生的磁共振声学噪声，即声音噪声，一直是磁共振成像（MRI）中的问题之一，无论是在患者扫描中，还是在精神病学和神经科学研究的许多领域，如脑功能磁共振成像（fMRI）中。特别是在脑功能磁共振成像中，声音噪声是严重的噪声源之一，它会掩盖从皮质和毛细血管中氧合状态的细微变化所获得的微弱信号。因此，我们研究了听觉、运动和视觉皮质的功能磁共振成像中产生的声学噪声，即声音噪声的影响。结果表明，声学噪声对运动和视觉反应的影响是相反的。也就是说，对于运动活动，总的运动激活增加，而对于视觉刺激，当受试者暴露在响亮的声音中时，相应的（视觉）皮质活动会大幅减少。尽管目前的观察是初步的，需要更多的实验证实，但似乎观察到的声学噪声对脑功能的影响，如在运动和视觉皮质中，是新的观察结果，可能会对未来功能磁共振成像研究中的数据观察和解释产生重大影响。
