Quantitative assessment of myocardial blood flow and extracellular volume fraction using 68Ga-DOTA-PET: A feasibility and validation study in large animals

Abstract

BackgroundHere we evaluated the feasibility of PET with Gallium-68 (68Ga)-labeled DOTA for non-invasive assessment of myocardial blood flow (MBF) and extracellular volume fraction (ECV) in a pig model of myocardial infarction. We also aimed to validate MBF measurements using microspheres as a gold standard in healthy pigs.Methods8 healthy pigs underwent three sequential 68Ga-DOTA-PET/CT scans at rest and during pharmacological stress with simultaneous injection of fluorescent microspheres to validate MBF measurements. Myocardial infarction was induced in 5 additional pigs, which underwent 68Ga-DOTA-PET/CT examinations 7-days after reperfusion. Dynamic PET images were reconstructed and fitted to obtain MBF and ECV parametric maps.ResultsMBF assessed with 68Ga-DOTA-PET showed good correlation (y\u2009=\u20090.96x\u2009+\u20090.11, r\u2009=\u20090.91) with that measured with microspheres. MBF values obtained with 68Ga-DOTA-PET in the infarcted area (LAD, left anterior descendant) were significantly reduced in comparison to remote ones LCX (left circumflex artery, P\u2009<\u20090.0001) and RCA (right coronary artery, P\u2009<\u20090.0001). ECV increased in the infarcted area (P\u2009<\u20090.0001).Conclusion68Ga-DOTA-PET allowed non-invasive assessment of MBF and ECV in pigs with myocardial infarction and under rest-stress conditions. This technique could provide wide access to quantitative measurement of both MBF and ECV with PET imaging.