Utility of 64-MSCT in assessing acute non-reperfused myocardial infarct size

OBJECTIVE To evaluate the utility of multi-slice computed tomography (MSCT) in assessing acute non-reperfused myocardial infarct size. METHODS Seven domestic pigs (mean weight 17.3 ± 1.9 kg) underwent ligation of the distal left anterior descending artery to establish a model of acute myocardial infarction (MI). MSCT and triphenyltetrazolium chloride (TTC) staining were performed two hours later. The following data were acquired and analyzed: MI volume (%), CT values of the infarcted region, left ventricular cavity and normal cardiac tissue at various scanning time-points (1, 5, 10, 15, 20 min after contrast injection). RESULTS Using MSCT, the overall MI volume showed a time-dependent decrease, with a reduction of 28.87% after 20 min. The greatest reduction occurred at the 5 min time-point. In TTC staining, MI volume was 9.87% ± 2.44%. When MI size, as determined by MSCT, was compared with that by TTC staining in Bland-Altman plots, there was a better agreement at 5, 10, and 15 min time-points at 1 and 20 min. CONCLUSIONS The study indicates that double-phase scanning examination using MSCT is a useful tool to assess MI size, and the optimal late-phase scanning time-point set within 5-15 min of contrast injection.