Physiological noise in oxygenation-sensitive magnetic resonance imaging
Physiological noise in oxygenation-sensitive magnetic resonance imaging
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DOI：
10.1002/mrm.1240
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发表时间：
2001-10-01
影响因子：
3.3
通讯作者：
Glover, GH
中科院分区：
文献类型：
--
作者：
Krüger, G;Glover, GH
在6名健康志愿者中，使用3.0 T氧合敏感双回波螺旋MRI研究了静息脑中的生理噪声，该噪声来自代谢相关脑生理学和细微脑脉动的波动。与系统噪声和热噪声相比，生理噪声表现出信号强度依赖性，并且是代谢相关噪声所特有的回声时间依赖性。通过改变翻转角和回波时间来改变MR信号强度，可以分离不同的噪声成分，并显示3.0 T下的生理噪声（1）超过其他噪声源，（2）皮质灰质中的生理噪声明显大于白色物质区域。在氧合敏感MRI的SNR预测饱和在较高的领域，这表明在3.0 T和更高的静息脑的噪声测量可以提供一个敏感的探头的功能信息。(C)2001 Wiley-Liss，Inc.
The physiological noise in the resting brain, which arises from fluctuations in metabolic-linked brain physiology and subtle brain pulsations, was investigated in six healthy volunteers using oxygenation-sensitive dual-echo spiral MRI at 3.0 T. In contrast to the system and thermal noise, the physiological noise demonstrates a signal strength dependency and, unique to the metabolic-linked noise, an echo-time dependency. Variations of the MR signal strength by changing the flip angle and echo time allowed separation of the different noise components and revealed that the physiological noise at 3.0 T (1) exceeds other noise sources and (2) is significantly greater in cortical gray matter than in white matter regions. The SNR in oxygenation-sensitive MRI is predicted to saturate at higher fields, suggesting that noise measurements of the resting brain at 3.0 T and higher may provide a sensitive probe of functional information. (C) 2001 Wiley-Liss, Inc.