Ramirez Marc S, Lee Jaehyuk, Walker Christopher M, Chen Yunyun, Kingsley Charles V, De La Cerda Jorge, Maldonado Kiersten L, Lai Stephen Y, Bankson James A
The Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA.
Magn Reson Med. 2015 May;73(5):1726-32. doi: 10.1002/mrm.25307. Epub 2014 Jun 5.
There is great potential for real-time investigation of metabolism with MRS and hyperpolarized (HP) (13) C agents. Unfortunately, HP technology has high associated costs and efficiency limitations that may constrain in vivo studies involving many animals. To improve the throughput of preclinical investigations, we evaluate the feasibility of performing HP MRS on multiple animals simultaneously.
Simulations helped assess the viability of a dual-coil strategy for spatially localized multivolume MRS. A dual-mouse system was assembled and characterized with bench- and scanner-based experiments. Enzyme phantoms mixed with HP [1-(13) C] pyruvate emulated real-time metabolism and offered a controlled mechanism for evaluating system performance. Finally, a normal mouse and a mouse bearing a subcutaneous xenograft of colon cancer were simultaneously scanned in vivo using an agent containing HP [1-(13) C] pyruvate.
Geometric separation/rotation, active decoupling, and use of low input impedance preamplifiers permitted an encode-by-channel approach for spatially localized MRS. A precalibrated shim allowed straightforward metabolite differentiation in enzyme phantom and in vivo experiments at 7 Tesla, with performance similar to conventional acquisitions.
The initial feasibility of multi-animal HP (13) C MRS was established. Throughput scales with the number of simultaneously scanned animals, demonstrating the potential for significant improvements in study efficiency.
磁共振波谱（MRS）和超极化（HP）（13）C 试剂在实时代谢研究方面具有巨大潜力。不幸的是，HP 技术相关成本高昂且效率有限，这可能会限制涉及多只动物的体内研究。为提高临床前研究的通量，我们评估了同时对多只动物进行 HP MRS 的可行性。
模拟有助于评估用于空间定位多体积 MRS 的双线圈策略的可行性。组装了双小鼠系统，并通过基于实验台和扫描仪的实验对其进行了表征。与 HP [1 - （13）C] 丙酮酸混合的酶体模模拟实时代谢，并提供了一种评估系统性能的可控机制。最后，使用含有 HP [1 - （13）C] 丙酮酸的试剂对一只正常小鼠和一只皮下接种结肠癌异种移植瘤的小鼠进行了体内同时扫描。
几何分离/旋转、有源去耦以及使用低输入阻抗前置放大器允许采用逐通道编码方法进行空间定位 MRS。预校准的匀场在 7 特斯拉的酶体模和体内实验中实现了直接的代谢物区分，其性能与传统采集相似。
确立了多动物 HP （13）C MRS 的初步可行性。通量随同时扫描动物的数量而增加，表明研究效率有显著提高的潜力。
