Functional Magnetic Resonance Imaging and Spectroscopy at 4 Tesla

BOLD对比度和信噪比（SNR）均依赖于场，并且在4T下大于1.5T下。对于使用fMRI的高级认知功能的研究，其中信噪比始终是一个问题，在高场的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效应，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fMRI都忽略了除了氢（1H）核之外的所有其他核，只是因为它们的灵敏度较低。然而，在高场，来自生物学上重要的核23 Na和17 O的SNR可以提供比BOLD fMRI可获得的更高的新信息，这是计划的。此外，对于高场的功能光谱，改善的光谱色散，以及更高的信噪比，是非常重要的优势，可用于脑功能的研究。本申请集中在一些新的项目的实施，这将有利于在计划中的4T机器上执行。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.