HIGHER SPEED, FIELD & SPATIAL RESOLUTION BRAIN 3D 1H MRS

描述（由申请人提供）：质子磁共振波谱（'H-MRS）观察到的代谢水平变化经常用于增强高灵敏度（但非特异性）MRI。在1.5特斯拉，MRS迄今已将MRI的解剖结构与癌症、癫痫、阿尔茨海默病、多发性硬化症、HIV感染、中风和其他中枢神经系统（CNS）疾病的潜在代谢联系起来。因此，预期高磁场（B 0）1.5T成像器将为1H-MRS提供非常需要的灵敏度提升。不幸的是，这还没有发生：将最有用的2维和3维（3D）H-MRS技术转换为高Bos受到以下因素的阻碍：高射频（BI）功率要求;降低信噪比（SNR）增益的短TZ;化学位移配准误差;以及缺乏软件来填隙、设计3D定位、评估和显示大型3D MRS数据集。 这种竞争性延续的长期目标是开发和实施30 'H-MRS方法，以解决上述问题，并在更高的BG下表现得更好。它们将是过去两个周期开发的混合技术的延伸。具体目标1将利用较短的T2：（a）通过在感兴趣体积上最佳交错“厚片”进行3D覆盖，每个厚片足够薄，以便在强梯度下用可用B1激发，从而最大限度地减少配准误差;以及（B）将空间分辨率提高到（（1 ~m）~体素，并将覆盖范围一直扩展到颅骨。Specific Aim 2将把3D定位引入我们的无回声、非定位、全头部的H-MRS中，以提供一个快速、成像侧、低分辨率的“代谢定位器”。“Specific Aim 3将利用增加的灵敏度在有限区域产生非常高的空间分辨率，（0.5 - 0.375 μ m）体素，例如，视神经或脊髓，这两者目前都无法触及。最后，Specific Aim 4将开发新的方法来检测和可视化不同代谢物空间分布之间的关系，以简化3D 'H MRS生成的惊人的、经常令人困惑的信息量。 该项目的健康相关性是其将空间分辨率增加、体积覆盖和采集时间更短的3D 'H-MRS方法扩展到高23 T磁场，以支持正在进行和未来的与多灶性和弥漫性疾病相关的CNS代谢研究。

DESCRIPTION (provided by applicant): Changes in metabolic levels observed with proton-magnetic-resonance-spectroscopy ('H-MRS) are frequently used to augment the highly sensitive (but not specific) MRI. At 1.5 Tesla, MRS has so far linked anatomy from MRI with the underlying metabolism in cancer, epilepsy, Alzheimer's disease, multiple sclerosis, HIV infection, stroke and other disorders of the central nervous system (CNS). Therefore, it was anticipated that high-magnetic-field (Bo ) 1.5 T) imagers would provide 'H-MRS a much needed boost in sensitivity. Unfortunately, that has not happened: Translating the most useful 2 and 3 dimensional (3D) 'H-MRS techniques to high-Bos has been stymied by high radio-frequency (BI) power requirements; short TZ reducing the signal-to-noise-ratio (SNR) gain; chemical shift misregistration errors; and scarcity of software to shim, design 3D localization, evaluate and display the large 3D MRS data sets. The long term goal of this competing continuation is to develop and implement 30 'H-MRS methods to address the above issues and perform better at higher BG. They will be extensions of the hybrid techniques developed in the past two cycles. Specific Aim 1 will exploit the shorter T2s for: (a) 3D coverage by optimal interleaving of "slabs," across the volume-of-interest, each thin enough to excite with the available B1 under strong gradients to minimize the misregistration error; and (b) increase the spatial resolution to ((1 ~m )~voxels, and extend coverage all the way to the skull. Specific Aim 2 will introduce 3D localization into our non-echo, non-localized, whole head 'H-MRS, to provide a rapid, imager-side, lower-resolution "metabolic localizer." Specific Aim 3 will utilize the increased sensitivity to produce very high spatial resolution, (0.5 - 0.375 ~m )~ voxels, in restricted regions, e.g., the optic nerve or spinal cord, both of which are currently inaccessible. Finally, Specific Aim 4 will develop novel methods to detect and visualize relationships between different metabolites' spatial distributions to simplify the staggering, often confusing, amount of information generated by 3D 'H MRS. The health relatedness of this project is its extension of increased spatial resolution, volume covered and shorter acquisition time 3D 'H-MRS methods to high, 23 T, magnetic fields, to support ongoing and future studies of CNS metabolism associated with multifocal and diffuse diseases.