Hyperpolarized 13C Metabolic MRI of the Human Heart: Initial Experience
Rationale: Altered cardiac energetics is known to play an important role in the progression towards heart failure. A non-invasive method for imaging metabolic markers that could be used in longitudinal studies would be useful for understanding therapeutic approaches that target metabolism.
Objective: To demonstrate the first hyperpolarized 13C metabolic magnetic resonance imaging (MRI) of the human heart.
Methods and Results: Four healthy subjects underwent conventional proton cardiac MRI followed by 13C imaging and spectroscopic acquisition immediately following intravenous administration of a 0.1 mmol/kg dose of hyperpolarized [1-13C]pyruvate. All subjects tolerated the procedure well with no adverse effects reported up to one month post-procedure. The [1-13C]pyruvate signal appeared within the chambers but not within the muscle. Imaging of the downstream metabolites showed 13C-bicarbonate signal mainly confined to the left ventricular myocardium whereas the [1-13C]lactate signal appeared both within the chambers and in the myocardium. The mean 13C image signal-to-noise ratio was 115 for [1-13C]pyruvate, 56 for 13C-bicarbonate, and 53 for [1-13C]lactate.
Conclusions: These results represent the first 13C images of the human heart. The appearance of 13C-bicarbonate signal after administration of hyperpolarized [1-13C]pyruvate was readily detected in this healthy cohort (N=4). This shows that assessment of pyruvate metabolism in vivo in humans is feasible using current technology.
- magnetic resonance imaging
- magnetic resonance spectroscopy
- metabolic imaging
- heart failure
- Received August 14, 2016.
- Revision received August 30, 2016.
- Accepted September 15, 2016.
Circulation Research is published on behalf of the American Heart Association, Inc., by Wolters Kluwer. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial-NoDervis License (http://creativecommons.org/licenses/by-nc-nd/3.0/), which permits use, distribution, and reproduction in any medium, provided that the original work is properly cited, the use is noncommercial, and no modifications or adaptations are made.