Spiral Spectroscopic Human Neuroimaging

描述(申请人提供)：磁共振光谱成像技术的广泛使用受到几个挑战的阻碍，包括低信噪比(SNR)、主场和RF激励场的不均匀、成像时间和体积覆盖的繁琐限制，以及从耦合或重叠的光谱分量中检测和分离信号的能力有限。针对这些限制，我们开发了光谱采集和处理方法，用于i)高场强(3T和7T)，提供更高的SNR、增加化学位移色散和简化耦合图案；ii)螺旋读出梯度，通过提供两个数量级的编码加速来解决MRSI中的空间编码限制；iii)并行射频传输，以缓解高场下射频激励的严重不均匀；以及iv)接收线圈阵列，以提高SNR并实现并行编码。一些有吸引力的光谱成像应用为这项工作提供了强大的动机，包括体积、高空间分辨率的光谱成像、大大减少了扫描时间以提高患者的耐受性，以及结合多维方法来检测细微不同的化学位移物种。

DESCRIPTION (provided by applicant): Widespread use of magnetic resonance spectroscopic imaging techniques is hindered by several challenges, including low signal-to-noise ratio (SNR), inhomogeneity of the main field and RF excitation field, cumbersome constraints on imaging time and volumetric coverage, and limited ability to detect and separate signals from coupled or overlapping spectral components. We address these limitations by developing spectroscopic acquisition and processing methods for i) high field strength (3T and 7T), providing higher SNR, increased chemical shift dispersion and simplified coupling patterns; ii) spiral readout gradients that address the spatial encoding limitations in MRSI by offering two orders of magnitude of encoding acceleration; iii) parallel RF transmission to mitigate the severe non-uniformity of RF excitation at high field; and iv) receive coil arrays to improve SNR and enable parallel encoding. Several attractive spectroscopic imaging applications provide a strong motivation for this work, including volumetric, high spatial resolution spectroscopic imaging, greatly reduced scan times for improved patient tolerance, and the incorporation of multidimensional methods to detect subtly different chemical shift species.