Accelerated Dual-Contrast First-Pass Perfusion MRI of the Mouse Heart: Development and Application to Diet-Induced Obese Mice

PurposeGene-modified mice may be used to elucidate molecular mechanisms underlying abnormal myocardial blow flow (MBF). We sought to develop a quantitative myocardial perfusion imaging technique for mice and to test the hypothesis that myocardial perfusion reserve (MPR) is reduced in a mouse model of diet-induced obesity (DIO). MethodsA dual-contrast saturation-recovery sequence with k(y)-t undersampling and a motion-compensated compressed sensing reconstruction algorithm was developed for first-pass MRI on a small-bore 7 Tesla system. Control mice were imaged at rest and with the vasodilators ATL313 and Regadenoson (n=6 each). In addition, we imaged mice fed a high-fat diet (HFD) for 24 weeks. ResultsIn control mice, MBF was 5.70.8 mL/g/min at rest and it increased to 11.8 +/- 0.6 mL/g/min with ATL313 and to 10.4 +/- 0.3 mL/g/min with Regadenoson. In HFD mice, we detected normal resting MBF (5.6 +/- 0.4 versus 5.0 +/- 0.3 on control diet), low MBF at stress (7.7 +/- 0.4 versus 10.4 +/- 0.3 on control diet, P<0.05), and reduced MPR (1.4 +/- 0.2 versus 2.0 +/- 0.3 on control diet, P<0.05). ConclusionAccelerated dual-contrast first-pass MRI with motion-compensated compressed sensing provides spatiotemporal resolution suitable for measuring MBF in free-breathing mice, and detected reduced MPR in DIO mice. These techniques may be used to study molecular mechanisms that underlie abnormal myocardial perfusion. Magn Reson Med 73:1237-1245, 2015. (c) 2014 Wiley Periodicals, Inc.