Tang Shuyu, Bok Robert, Qin Hecong, Reed Galen, VanCriekinge Mark, Delos Santos Romelyn, Overall William, Santos Juan, Gordon Jeremy, Wang Zhen Jane, Vigneron Daniel B, Larson Peder E Z
UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA.
Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA.
Magn Reson Med. 2020 Sep;84(3):1113-1125. doi: 10.1002/mrm.28204. Epub 2020 Feb 21.
The balanced steady-state free precession sequence has been previously explored to improve the efficient use of nonrecoverable hyperpolarized C magnetization, but suffers from poor spectral selectivity and long acquisition time. The purpose of this study was to develop a novel metabolite-specific 3D bSSFP ("MS-3DSSFP") sequence with stack-of-spiral readouts for improved lactate imaging in hyperpolarized [1- C]pyruvate studies on a clinical 3T scanner.
Simulations were performed to evaluate the spectral response of the MS-3DSSFP sequence. Thermal C phantom experiments were performed to validate the MS-3DSSFP sequence. In vivo hyperpolarized [1- C], pyruvate studies were performed to compare the MS-3DSSFP sequence with metabolite-specific gradient echo ("MS-GRE") sequences for lactate imaging.
Simulations, phantom, and in vivo studies demonstrate that the MS-3DSSFP sequence achieved spectrally selective excitation on lactate while minimally perturbing other metabolites. Compared with MS-GRE sequences, the MS-3DSSFP sequence showed approximately a 2.5-fold SNR improvement for lactate imaging in rat kidneys, prostate tumors in a mouse model, and human kidneys.
Improved lactate imaging using the MS-3DSSFP sequence in hyperpolarized [1- C]pyruvate studies was demonstrated in animals and humans. The MS-3DSSFP sequence could be applied for other clinical applications such as in the brain or adapted for imaging other metabolites such as pyruvate and bicarbonate.
平衡稳态自由进动序列此前已被探索用于提高不可恢复的超极化碳磁化的有效利用，但存在光谱选择性差和采集时间长的问题。本研究的目的是开发一种具有螺旋读出堆栈的新型代谢物特异性三维稳态自由进动（“MS-3DSSFP”）序列，以在临床3T扫描仪上的超极化[1- C]丙酮酸研究中改善乳酸成像。
进行模拟以评估MS-3DSSFP序列的光谱响应。进行热碳体模实验以验证MS-3DSSFP序列。进行体内超极化[1- C]丙酮酸研究，以将MS-3DSSFP序列与代谢物特异性梯度回波（“MS-GRE”）序列用于乳酸成像进行比较。
模拟、体模和体内研究表明，MS-3DSSFP序列在对乳酸实现光谱选择性激发的同时，对其他代谢物的干扰最小。与MS-GRE序列相比，MS-3DSSFP序列在大鼠肾脏、小鼠模型中的前列腺肿瘤和人类肾脏的乳酸成像中显示出约2.5倍的信噪比改善。
在动物和人类中证明了在超极化[1- C]丙酮酸研究中使用MS-3DSSFP序列可改善乳酸成像。MS-3DSSFP序列可应用于其他临床应用，如脑部，或适用于成像其他代谢物，如丙酮酸和碳酸氢盐。
