Integrated Bloch-Siegert B1 mapping and multislice imaging of hyperpolarized 13C pyruvate and bicarbonate in the heart
Integrated Bloch-Siegert B1 mapping and multislice imaging of hyperpolarized 13C pyruvate and bicarbonate in the heart
复制标题
DOI：
10.1002/mrm.22977
复制
发表时间：
2012-01-01
影响因子：
3.3
通讯作者：
Cunningham, Charles H.
中科院分区：
文献类型：
--
作者：
Lau, Angus Z.;Chen, Albert P.;Cunningham, Charles H.
通过动态核极化的13 C标记底物的超极化已被用作非侵入性研究体内发生的实时代谢过程的方法。在这些研究中，需要对射频发射功率进行适当的校准，以有效地观察快速衰减的磁化。传统的发射射频场（B-1（+））标测方法依赖于在成像之前将磁化置于固定的已知状态，使得它们不适合于超极化磁化的成像。最近，基于Bloch-Siegert位移的基于相位的B1映射方法已经被报道。该方法使用在非共振射频脉冲的存在下原子核的共振频率中的B-1依赖性偏移。在这篇文章中，我们研究了Bloch-Siegert B-1作图的可行性，并观察了体内单次注射超极化[1-C-13]丙酮酸盐的代谢。该技术通过体模实验以及在正常大鼠和猪体内的实验进行了验证。该方法预计将通过实现精确的翻转角校正来改善体内超极化C-13代谢的定量测量。这项工作演示了使用Bloch-Siegert B-1映射下具有挑战性的平衡成像条件。Magn Reson Med 67：62-71，2012年。(C)2011 Wiley-Liss，Inc.
Hyperpolarization of 13C labeled substrates via dynamic nuclear polarization has been used as a method to noninvasively study real-time metabolic processes occurring in vivo. In these studies, proper calibration of radiofrequency transmit power is required to efficiently observe rapidly decaying magnetization. Conventional transmit radiofrequency field (B-1(+)) mapping methods rely on placing magnetization in a fixed, known state prior to imaging, making them unsuitable for imaging of hyperpolarized magnetization. Recently, a phase-based B1 mapping method based on the Bloch-Siegert shift has been reported. This method uses a B-1-dependent shift in the resonance frequency of nuclei in the presence of an off-resonance radiofrequency pulse. In this article, we investigate the feasibility of Bloch-Siegert B-1 mapping and observation of metabolism of hyperpolarized [1-C-13] pyruvate in vivo, in a single injection. The technique is demonstrated with phantom experiments, and in normal rat and pigs in vivo. This method is anticipated to improve quantitative measurements of hyperpolarized C-13 metabolism in vivo by enabling accurate flip-angle corrections. This work demonstrates the use of Bloch-Siegert B-1 mapping under challenging out-of-equilibrium imaging conditions. Magn Reson Med 67:62-71, 2012. (C) 2011 Wiley-Liss, Inc.