Kawada Yuuki, Hirata Hiroshi, Fujii Hirodata
Department of Electrical Engineering, Yamagata University, Yonezawa, Yamagata 992-8510, Japan.
J Magn Reson. 2007 Jan;184(1):29-38. doi: 10.1016/j.jmr.2006.09.014. Epub 2006 Oct 6.
This article reports experimental investigations on the use of RF resonators for continuous-wave electron paramagnetic resonance (cw-EPR) and proton nuclear magnetic resonance (NMR) imaging. We developed a composite resonator system with multi-coil parallel-gap resonators for co-registration EPR/NMR imaging. The resonance frequencies of each resonator were 21.8MHz for NMR and 670MHz for EPR. A smaller resonator (22mm in diameter) for use in EPR was placed coaxially in a larger resonator (40mm in diameter) for use in NMR. RF magnetic fields in the composite resonator system were visualized by measuring a homogeneous 4-hydroxy-2,2,6,6-tetramethyl-piperidinooxy (4-hydroxy-TEMPO) solution in a test tube. A phantom of five tubes containing distilled water and 4-hydroxy-TEMPO solution was also measured to demonstrate the potential usefulness of this composite resonator system in biomedical science. An image of unpaired electrons was obtained for 4-hydroxy-TEMPO in three tubes, and was successfully mapped on the proton image for five tubes. Technical problems in the implementation of a composite resonator system are discussed with regard to co-registration EPR/NMR imaging for animal experiments.
本文报道了关于使用射频谐振器进行连续波电子顺磁共振（cw-EPR）和质子核磁共振（NMR）成像的实验研究。我们开发了一种带有多线圈平行间隙谐振器的复合谐振器系统，用于EPR/NMR联合成像。每个谐振器的共振频率，NMR为21.8MHz，EPR为670MHz。用于EPR的较小谐振器（直径22mm）同轴放置在用于NMR的较大谐振器（直径40mm）中。通过测量试管中均匀的4-羟基-2,2,6,6-四甲基哌啶氮氧化物（4-羟基-TEMPO）溶液，可视化复合谐振器系统中的射频磁场。还测量了一个包含蒸馏水和4-羟基-TEMPO溶液的五管模型，以证明这种复合谐振器系统在生物医学科学中的潜在用途。获得了三个管中4-羟基-TEMPO的未配对电子图像，并成功地映射到了五管的质子图像上。针对动物实验的EPR/NMR联合成像，讨论了复合谐振器系统实施中的技术问题。
