Global Applied Science Laboratory, GE Healthcare, CA, USA.
NMR Biomed. 2010 May;23(4):414-23. doi: 10.1002/nbm.1481. Epub 2010 Feb 19.
A single-voxel Carr-Purcell-Meibloom-Gill sequence was developed to measure localized T(2) relaxation times of (13)C-labeled metabolites in vivo for the first time. Following hyperpolarized [1-(13)C]pyruvate injections, pyruvate and its metabolic products, alanine and lactate, were observed in the liver of five rats with hepatocellular carcinoma and five healthy control rats. The T(2) relaxation times of alanine and lactate were both significantly longer in HCC tumors than in normal livers (p < 0.002). The HCC tumors also showed significantly higher alanine signal relative to the total (13)C signal than normal livers (p < 0.006). The intra- and inter-subject variations of the alanine T(2) relaxation time were 11% and 13%, respectively. The intra- and inter-subject variations of the lactate T(2) relaxation time were 6% and 7%, respectively. The intra-subject variability of alanine to total carbon ratio was 16% and the inter-subject variability 28%. The intra-subject variability of lactate to total carbon ratio was 14% and the inter-subject variability 20%. The study results show that the signal level and relaxivity of [1-(13)C]alanine may be promising biomarkers for HCC tumors. Its diagnostic values in HCC staging and treatment monitoring are yet to be explored.
首次开发了单体素 Carr-Purcell-Meibloom-Gill 序列，用于测量体内（13）C 标记代谢物的局部 T（2）弛豫时间。在超极化 [1-（13）C]丙酮酸注射后，在五例肝细胞癌大鼠和五例健康对照大鼠的肝脏中观察到丙酮酸及其代谢产物丙氨酸和乳酸。丙氨酸和乳酸的 T（2）弛豫时间在 HCC 肿瘤中均明显长于正常肝脏（p < 0.002）。HCC 肿瘤中丙氨酸信号相对于总（13）C 信号也明显高于正常肝脏（p < 0.006）。丙氨酸 T（2）弛豫时间的个体内和个体间变异性分别为 11%和 13%。乳酸 T（2）弛豫时间的个体内和个体间变异性分别为 6%和 7%。丙氨酸与总碳比的个体内变异性为 16%，个体间变异性为 28%。乳酸与总碳比的个体内变异性为 14%，个体间变异性为 20%。研究结果表明，[1-（13）C]丙氨酸的信号水平和弛豫率可能是 HCC 肿瘤的有前途的生物标志物。其在 HCC 分期和治疗监测中的诊断价值尚待探索。
