Background: We sought to determine the accuracy of quantitative myocardial contrast echocardiography (MCE) in predicting transmural extent of infarction (TEI) and viability by comparison with contrast-enhanced magnetic resonance imaging (ceMRI). Methods: Real-time low mechanical index (MI), high MI MCE and ceMRI were performed 7 days after successful percutaneous revascularization in 30 patients with acute myocardial infarction. Myocardial blood flow (MBF) was calculated as Ax棺 (dB/sec) using the equation of y=A (1-e-棺t), which fit the replenishment curve of low MI MCE. Myocardial blood volume fraction (MBVF, ml/100g myocardium) was calculated as 100x10 relative CI/10, using the relative contrast intensity (CI) by subtracting the cavity CI from the adjacent transmural CI using high MI MCE in all 16 segments of each patients. CeMRI derived percentage delayed hyperenhancement (DH) area of each segment was calculated. A baseline and 3-month follow-up echo were performed to evaluate regional wall motion change. Results: MBVF correlated significantly with MBF (r=0.650, p<0.001). The segments were subdivided into five groups as follows: no DH (n=199), 1-25% DH (n=45), 25-50% DH (n=51), 51-75% DH (n=38), and 76-100% DH (n=49). An increase in the extent of DH was significantly related to a decrease in MBVF (p<0.001) and MBF (p<0.001). The optimal cutoff MBVF for predicting > 50% DH and persistent akinesis or dyskinesis were 1.92 ml (sensitivity 81% and specificity 85%, p < 0.01) and 1.63 ml (sensitivity 74% and specificity 75%, p < 0.01), respectively. Conclusions: MCE-derived transmural MBVF and MBF can be effective predictors of TEI and myocardial viability.