Functional Magnetic Resonance Imaging and Spectroscopy at 4 Tesla

BOLD对比度和信噪比（SNR）都与场相关，并且在4T时比1.5T时更大。对于使用fMRI研究高级认知功能，其中的信噪比一直是一个问题，在高场测量已被证明是有利的。由于更高的认知功能涉及更微妙的影响，以及随之而来的更小的BOLD反应，因此高场MRI系统对于此类实验至关重要。目前的大部分功能磁共振成像都忽略了除氢（1H）核以外的所有其他核，因为它们的灵敏度较低。然而，在高磁场下，生物学上重要的核23Na和17O的信噪比可以提供比BOLD fMRI获得的更多的新信息，这是计划中的。此外，对于高场功能光谱，改善的光谱色散和更高的信噪比是非常重要的优势，可以用于对脑功能的研究。这个应用程序的重点是实现一些新颖的项目，这些项目将从在计划的4T机器上执行中受益匪浅。方法学的发展将用于回答神经科学和临床感兴趣的问题。

The BOLD contrast and signal-to-noise ratio (SNR) are both field-dependent and are greater at 4T than at 1.5T. For the study of higher cognitive function using fMRI, where the signal-to-noise is always an issue, measurement at high fields has been shown to be advantageous. Since higher cognitive function involves more subtle effects, and a concomitantly smaller BOLD response, a high-field MRI system is essential for such experiments.Much of current fMRI has neglected all other nuclei apart from the hydrogen (1H) nucleus simply because their sensitivity is lower. At high fields, however, the SNR from the biologically-important nuclei 23Na and 17O, which can provide new information over and above that obtainable with BOLD fMRI, is planned.Further, for functional spectroscopy at high field, the improved spectral dispersion, as well as the higher signal-to-noise ratio, are extremely important advantages which may be exploited for the investigation ob brain function.This aplication is focused on the implementation of a number of novel projects which would benefit enormously from execution on the planned 4T machine. Methodological developments will be used to answer questions of neuroscientific and clinical interest.