INTEGRATED MRI ASSESSMENT OF REGIONAL FUNCTION AND PERFUSION IN CANINE MYOCARDIAL-INFARCTION

A single integrated examination using regional measurements of perfusi on from contrast-enhanced MRI and three-dimensional (3D) strain from t issue-tagged MRI was developed to differentiate infarcted myocardium f rom adjacent tissue with functional abnormalities. Ten dogs were studi ed at baseline and 10 days after a P-hour occlusion of the left anteri or descending coronary artery (LAD). Strain was determined using a 3D finite element model. Two-dimensional measurements of hypoenhancing re gions were highly correlated with myocardial viability (r = 0.96), Sig nal intensity versus time curves obtained from contrast-enhanced MRI w ere used for quantitative perfusion analysis, The remote and adjacent noninfarcted tissue of the dogs with LAD occlusion, as well as the inf arcted tissue, exhibited abnormal deformation patterns as compared to normal dogs (positive predictive value (PPV) of strain determination o f infarction = 66%), Integration of contrast-enhanced MRI results with 3D strain analysis enabled the delineation of the myocardial infarcti on (PPV = 100%) from functionally compromised myocardium. This integra ted cardiac examination shows promise for noninvasive serial assessmen t of potentially jeopardized noninfarcted myocardium to study the proc ess of infarct remodeling and expansion.