Spiral Spectroscopic Human Neuroimaging

磁共振光谱成像技术的广泛使用受到若干挑战的阻碍，包括低信噪比（SNR）、主场和RF激励场的不均匀性、对成像时间和体积覆盖的繁琐约束、以及从耦合或重叠的谱分量检测和分离信号的能力有限。我们通过开发光谱采集和处理方法来解决这些限制，ii）螺旋读出梯度，其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RF传输，以减轻高场下RF激励的严重不均匀性;以及iv）接收线圈阵列，以提高SNR并实现并行编码。几个有吸引力的光谱成像应用提供了一个强大的动力，这项工作，包括体积，高空间分辨率光谱成像，大大减少扫描时间，提高病人的耐受性，并纳入多维方法来检测微妙的不同化学位移物种。

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.