Evaluation of acute myocardial infarction and reperfusion with multi-slice spiral CT in dogs: experimental study

Objective To evaluate acute myocardial infarction and reperfusion after obstruction of coronary artery with 16-slice spiral CT by animal model. Methods Twelve hybrid canines were divided into two groups. The pre-enhanced CT and contrast-enhanced CT at one and two hours after ligation of left anterior descending artery (LAD) were performed in acute myocardial infarction group (AMI), respectively. The same CT scanning at one hour after ligation of LAD and 30 min after reperfusion was also performed in AMI reperfusion group, respectively. The morphological features of ischemic myocardium were observed. The CT values of normal and ischemic myocardium were measured. The M/L ratios of the CT value of normal and infarction myocardium to that of left ventricle cavity were calculated. Results The infarction areas of all 12 hybrids showed low density at one hour after ligation of LAD. The density of infarction area was much lower at 2 hours after ligation of vessel in AMI group. In AMI reperfusion group, the density of lesion area did not obviously change after 30 mins reperfusion. For AMI group, significant differences of the CT values and the M/L ratios at one or two hours after ligation of LAD existed (P0.001). For AMI reperfusion group, significant differences of the values above mentioned also existed at one hour after ligation and 30mins after reperfusion (P0.001). Conclusion Acute myocardial infarction area showed low density on the contrast-enhanced CT image. MSCT can distinguish the infarction myocardium and normal area.