Hyperpolarized (13)C 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 (13)C substrates, which preserves bolus magnetization inside the blood pool, is presented. The proposed method is evaluated against gadolinium-enhanced (1)H 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 (13)C urea with the velocity-selective vs. conventional excitation, as well as standard (1)H 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 (1)H gadolinium data (9–15%). Overall image quality appears comparable between the velocity-selective hyperpolarized and gadolinium-enhanced imaging. CONCLUSION: The feasibility of hyperpolarized (13)C first-pass perfusion CMR has been demonstrated in swine. Comparison with reference (1)H gadolinium data revealed sufficient data quality and indicates the potential of hyperpolarized perfusion imaging for human applications. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12968-017-0364-4) contains supplementary material, which is available to authorized users.