Relationship of MRI Delayed Contrast Enhancement to Irreversible Injury, Infarct Age, and Contractile Function
Raymond J. Kim, David S. Fieno, Todd B. Parrish, Kathleen R. Harris, Enn-Ling Chen, Orlando P. Simonetti +4 more
Circulation
Abstract
BACKGROUND: Contrast MRI enhancement patterns in several pathophysiologies resulting from ischemic myocardial injury are controversial or have not been investigated. We compared contrast enhancement in acute infarction (AI), after severe but reversible ischemic injury (RII), and in chronic infarction. METHODS AND RESULTS: In dogs, a large coronary artery was occluded to study AI and/or chronic infarction (n = 18), and a second coronary artery was chronically instrumented with a reversible hydraulic occluder and Doppler flowmeter to study RII (n = 8). At 3 days after surgery, cine MRI revealed reduced wall thickening in AI (5+/-6% versus 33+/-6% in normal, P<0.001). In RII, wall thickening before, during, and after inflation of the occluder for 15 minutes was 35+/-5%, 1+/-8%, and 21+/-10% a