Hyperpolarized 13C urea myocardial first-pass perfusion imaging using velocity-selective excitation

Background: a velocity-selective binomial excitation scheme for myocardial first-pass perfusion measurements with hyperpolarized 13c substrates,which preserves bolus magnetization inside the blood pool,is presented. the proposed method is evaluated against gadolinium-enhanced 1h measurements in-vivo. methods: the proposed excitation with an echo-planar imaging readout was implemented on a clinical cmr system. dynamic myocardial stress perfusion images were acquired in six healthy pigs after bolus injection of hyperpolarized 13c urea with the velocity-selective vs. conventional excitation,as well as standard 1h gadolinium-enhanced images. signal-to-noise,contrast-to-noise (cnr) and homogeneity of semi-quantitative perfusion measures were compared between methods based on first-pass signal-intensity time curves extracted from a mid-ventricular slice. diagnostic feasibility is demonstrated in a case of septal infarction. results: velocity-selective excitation provides over three-fold reduction in blood pool signal with a two-fold increase in myocardial cnr. extracted first-pass perfusion curves reveal a significantly reduced variability of semi-quantitative first-pass perfusion measures (12-20%) for velocity-selective excitation compared to conventional excitation (28-93%),comparable to that of reference 1h gadolinium data (9-15%). overall image quality appears comparable between the velocity-selective hyperpolarized and gadolinium-enhanced imaging. conclusion: the feasibility of hyperpolarized 13c first-pass perfusion cmr has been demonstrated in swine. comparison with reference 1h gadolinium data revealed sufficient data quality and indicates the potential of hyperpolarized perfusion imaging for human applications. © 2017 the author(s).