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。到目前为止，在1.5特斯拉的功率下，MRS已经将核磁共振成像的解剖学与癌症、癫痫、阿尔茨海默病、多发性硬化症、艾滋病毒感染、中风和其他中枢神经系统疾病的潜在代谢联系起来。因此，预计高磁场（Bo） 1.5 T成像仪将为H-MRS提供急需的灵敏度提升。不幸的是，这种情况并未发生：将最有用的2维和3维（3D） H-MRS技术转化为高bos一直受到高射频（BI）功率要求的阻碍；短TZ降低信噪比（SNR）增益；化学位移错配误差；缺乏软件来填充、设计3D定位、评估和显示大型3D MRS数据集。

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.