Kohler S J, Yen Y, Wolber J, Chen A P, Albers M J, Bok R, Zhang V, Tropp J, Nelson S, Vigneron D B, Kurhanewicz J, Hurd R E
GE Healthcare, Menlo Park, California, USA.
GE Healthcare, Amersham, UK.
Magn Reson Med. 2007 Jul;58(1):65-69. doi: 10.1002/mrm.21253.
We present for the first time dynamic spectra and spectroscopic images acquired in normal rats at 3T following the injection of (13)C-1-pyruvate that was hyperpolarized by the dynamic nuclear polarization (DNP) method. Spectroscopic sampling was optimized for signal-to-noise ratio (SNR) and for spectral resolution of (13)C-1-pyruvate and its metabolic products (13)C-1-alanine, (13)C-1-lactate, and (13)C-bicarbonate. Dynamic spectra in rats were collected with a temporal resolution of 3 s from a 90-mm axial slab using a dual (1)H-(13)C quadrature birdcage coil to observe the combined effects of metabolism, flow, and T(1) relaxation. In separate experiments, spectroscopic imaging data were obtained during a 17-s acquisition of a 20-mm axial slice centered on the rat kidney region to provide information on the spatial distribution of the metabolites. Conversion of pyruvate to lactate, alanine, and bicarbonate occurred within a minute of injection. Alanine was observed primarily in skeletal muscle and liver, while pyruvate, lactate, and bicarbonate concentrations were relatively high in the vasculature and kidneys. In contrast to earlier work at 1.5 T, bicarbonate was routinely observed in skeletal muscle as well as the kidney and vasculature.
我们首次展示了在3T场强下对正常大鼠注射经动态核极化（DNP）方法超极化的(13)C-1-丙酮酸后获得的动态光谱和光谱图像。光谱采样针对信噪比（SNR）以及(13)C-1-丙酮酸及其代谢产物(13)C-1-丙氨酸、(13)C-1-乳酸和(13)C-碳酸氢盐的光谱分辨率进行了优化。使用双(1)H-(13)C正交鸟笼线圈，从90毫米轴向层面以3秒的时间分辨率采集大鼠的动态光谱，以观察代谢、血流和T(1)弛豫的综合影响。在单独的实验中，在对以大鼠肾区为中心的20毫米轴向切片进行17秒采集期间获取光谱成像数据，以提供有关代谢物空间分布的信息。丙酮酸向乳酸、丙氨酸和碳酸氢盐的转化在注射后一分钟内发生。丙氨酸主要在骨骼肌和肝脏中观察到，而丙酮酸、乳酸和碳酸氢盐在血管和肾脏中的浓度相对较高。与早期在1.5T场强下的研究不同，在骨骼肌以及肾脏和血管中都常规观察到了碳酸氢盐。
