Magnetic Resonance Imaging of Myocardial Perfusion and Viability Using a Blood Pool Contrast Agent

Abstract

A comprehensive cardiac magnetic resonance (MR) examination should comprise imaging of myocardial perfusion, viability, and the coronary arteries. Blood pool contrast agents (BPCAs) improve coronary MR angiography, whereas their potential for imaging of perfusion and viability is unknown. The abilities to noninvasively image myocardial perfusion and viability using the BPCA P792 (Guerbet, France) were tested in a closed-chest model of nonreperfused myocardial infarction in 5 pigs.Two to 3 days after instrumentation, myocardial perfusion imaging with a saturation-recovery steady-state free precession technique and viability imaging with an inversion-recovery fast low-angle shot sequence were conducted on a 1.5-T MR scanner using the extracellular contrast agents (ECCA) Gd-DOTA (0.1 mmol Gd/kg) and blood pool contrast agent (BPCA) P792 (0.013 mmol Gd/kg).Perfusion defects were visualized in all pigs with good correlation between the ECCA and the BPCA (1.77 +/- 1.16 cm2 vs. 1.80 +/- 1.19 cm2, r = 0.959, P < 0.01). Reduced myocardial perfusion was detected using the ECCA up to 80 seconds after injection. In contrast, BPCA administration enabled visualization of perfusion defects on equilibrium perfusion imaging in all cases for 10 minutes. The size of myocardial infarction detected with viability MR imaging correlated well between the standard method (ECCA) and delayed-enhancement imaging with the BPCA (5.40 +/- 3.16 versus 5.52 +/- 3.13 cm3, r = 0.994, P < 0.002).The BPCA investigated in this study allows both reliable detection of perfusion defects on first pass and equilibrium perfusion imaging and characterization of viability after myocardial infarction. Thus, this contrast agent is suitable for a comprehensive cardiac MR examination.