Development of MR active contrast agents via Parahydrogen Induced Polarization

摘要

Parahydrogen Induced Polarization provides dramatic MR signal enhancement that can be exploited for molecular imaging. This method allows amongst others for Magnetic Resonance Imaging of 13C and 15N, which is usually constrained by the low MR sensitivity of these nuclei. By combining hydrogenation of barbiturates with parahydrogen under special experimental conditions (PASADENA under pressure) with a polarization transfer sequence we demonstrate the transfer of the initial 'H polarization to 13C. The polarization transfer yields a signal increase for I3C of more than 1000. Hence, the role of certain target compounds such as anesthetics like the barbituric acid derivatives could be investigated using MRI techniques. Moreover, we present the first MRI experiments on antiphase PHIP polarized protons in the liquid phase using the model system hexyne/hexene. Our results show that it is possible to get images of good quality and high SNR with PHIP polarized protons and that no artifacts are created by the antiphase character of the *H signal.