Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt am Main, Germany.
Comprehensive Heart Failure Center, University Hospital Würzburg, Würzburg, Germany.
Sci Rep. 2017 Mar 14;7:44010. doi: 10.1038/srep44010.
Here we describe a new hyperpolarization approach for magnetic resonance imaging applications at 1.5 T. Proton signal enhancements of more than 20 were achieved with a newly designed multimode microwave resonator situated inside the bore of the imager and used for Overhauser dynamic nuclear polarization of the water proton signal. Different from other approaches in our setup the hyperpolarization is achieved continuously by liquid water flowing through the polarizer under continuous microwave excitation. With an available flow rate of up to 1.5 ml/min, which should be high enough for DNP MR angiography applications in small animals like mice and rats. The hyperpolarized liquid cooled to physiological temperature can be routed by a mechanical switch to a quartz capillary for injection into the blood vessels of the target object. This new approach allows hyperpolarization of protons without the need of an additional magnet and avoids the losses arising from the transfer of the hyperpolarized solution between magnets. The signal-to-noise improvement of this method is demonstrated on two- and three-dimensional phantoms of blood vessels.
在这里，我们描述了一种用于 1.5T 磁共振成像应用的新的极化方法。通过在成像仪内腔中使用新设计的多模微波谐振器实现了超过 20 倍的质子信号增强，该谐振器用于水质子信号的 Overhauser 动态核极化。与我们设置中的其他方法不同，通过在连续微波激发下流经极化器的液态水连续实现极化。在高达 1.5ml/min 的可用流速下，这对于像小鼠和大鼠这样的小动物的 DNP MR 血管造影应用应该足够高。冷却至生理温度的超极化液体可以通过机械开关路由到石英毛细管，以便注入目标物体的血管。这种新方法允许在不需要额外磁铁的情况下对质子进行极化，并避免了由于在磁铁之间转移超极化溶液而产生的损失。该方法的信噪比改善在二维和三维血管体模上得到了证明。
