
Real‐time cardiac metabolism assessed with hyperpolarized [1‐ 13 C]acetate in a large‐animal model
Author(s) -
Flori Alessandra,
Liserani Matteo,
Frijia Francesca,
Giovannetti Giulio,
Lionetti Vincenzo,
Casieri Valentina,
Positano Vincenzo,
Aquaro Giovanni Donato,
Recchia Fabio A.,
Santarelli Maria Filomena,
Landini Luigi,
ArdenkjaerLarsen Jan Henrik,
Menichetti Luca
Publication year - 2014
Publication title -
contrast media & molecular imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.714
H-Index - 50
eISSN - 1555-4317
pISSN - 1555-4309
DOI - 10.1002/cmmi.1618
Subject(s) - chemistry , in vivo , microbiology and biotechnology , biology
Dissolution‐dynamic nuclear polarization (dissolution‐DNP) for magnetic resonance (MR) spectroscopic imaging has recently emerged as a novel technique for noninvasive studies of the metabolic fate of biomolecules in vivo . Since acetate is the most abundant extra‐ and intracellular short‐chain fatty acid, we focused on [1‐ 13 C]acetate as a promising candidate for a chemical probe to study the myocardial metabolism of a beating heart. The dissolution‐DNP procedure of Na[1‐ 13 C]acetate for in vivo cardiac applications with a 3 T MR scanner was optimized in pigs during bolus injection of doses of up to 3 mmol. The Na[1‐ 13 C]acetate formulation was characterized by a liquid‐state polarization of 14.2% and a T 1Eff in vivo of 17.6 ± 1.7 s. In vivo Na[1‐ 13 C]acetate kinetics displayed a bimodal shape: [1‐ 13 C]acetyl carnitine (AcC) was detected in a slice covering the cardiac volume, and the signal of 13 C‐acetate and 13 C‐AcC was modeled using the total area under the curve (AUC) for kinetic analysis. A good correlation was found between the ratio AUC(AcC)/AUC(acetate) and the apparent kinetic constant of metabolic conversion, from [1‐ 13 C]acetate to [1‐ 13 C]AcC (k AcC ), divided by the AcC longitudinal relaxation rate (r 1 ). Our study proved the feasibility and the limitations of administration of large doses of hyperpolarized [1‐ 13 C]acetate to study the myocardial conversion of [1‐ 13 C]acetate in [1‐ 13 C]acetyl‐carnitine generated by acetyltransferase in healthy pigs. Copyright © 2014 John Wiley & Sons, Ltd.