METHODS: Healthy volunteers (n = 5), were injected with HP [1-13C]pyruvate dissolved in D2O and imaged with a metabolite-specific 3D dual-echo dynamic EPI sequence at 3T at one site (Site 1). Volunteers were monitored following the procedure to assess safety. Image characteristics, including SNR, were compared to data acquired in a separate cohort using water as a solvent (n = 5) at another site (Site 2). The apparent spin-lattice relaxation time (T1) of [1-13C]pyruvate was determined both in vitro and in vivo from a mono-exponential fit to the image intensity at each time point of our dynamic data.
RESULTS: All volunteers completed the study safely and reported no adverse effects. The use of D2O increased the T1 of [1-13C]pyruvate from 66.5 ± 1.6 s to 92.1 ± 5.1 s in vitro, which resulted in an increase in signal by a factor of 1.46 ± 0.03 at the time of injection (90 s after dissolution). The use of D2O also increased the apparent relaxation time of [1-13C]pyruvate by a factor of 1.4 ± 0.2 in vivo. After adjusting for inter-site SNR differences, the use of D2O was shown to increase image SNR by a factor of 2.6 ± 0.2 in humans.
CONCLUSIONS: HP [1-13C]pyruvate in D2O is safe for human imaging and provides an increase in T1 and SNR that may improve image quality.
方法:健康志愿者(n=5),注射溶解在D2O中的HP[1-13C]丙酮酸盐,并在一个部位(部位1)的3T处使用代谢物特异性3D双回波动态EPI序列进行成像。按照该程序监测志愿者以评估安全性。图像特征,包括SNR,将其与在另一个地点(地点2)使用水作为溶剂(n=5)的单独队列中获得的数据进行比较。[1-13C]丙酮酸盐的表观自旋晶格弛豫时间(T1)在体外和体内均从单指数拟合到我们动态数据的每个时间点的图像强度。
结果:所有志愿者均安全完成研究,报告无不良反应。D2O的使用使[1-13C]丙酮酸的T1在体外从66.5±1.6s增加到92.1±5.1s,这导致在注射时(溶解后90秒)信号增加1.46±0.03倍。D2O的使用还使[1-13C]丙酮酸的表观弛豫时间增加了1.4±0.2倍。调整站点间SNR差异后,在人类中,使用D2O可以将图像信噪比提高2.6±0.2倍。
结论:D2O中的HP[1-13C]丙酮酸盐对于人体成像是安全的,并且提供了T1和SNR的增加,这可能会改善图像质量。