ABSTRACT
Objective To explore the value of dual-phase contrast-enhancement multislice computed tomography (MSCT) in the assessment of acute myocardial infarction volume and perfusion in porcine models. Methods The distal left anterior descending coronary arteries of 5 pigs were balloon-occluded for 90 min and followed by reperfusion. MSCT was performed 1 min (early phase) and 5 min (delayed phase) after administration bolus of 100 mL of iodinated contrast material 30 min after reperfusion. On the same day, hearts were excised, sectioned in 8 mm short-axis slices, and stained with TTC. Infarction volume was defined as the sum of the hyper-enhanced area and surrounding hypo-enhanced area in all slices on delay enhanced phase of MSCT and the TTC-negative area on TTC staining slices. Infarction volume was expressed as percentage of total slice volume. Results Acute infarction detected by MSCT was characterized by early myocardial perfasion defects in the early phase of the contrast bolus (early defects) with surrounding residual defects and late enhancement observed in the late phase. Mean CT attenuation value of early defects was significantly different from CT attenuation value of remote myocardium [(213±55)HU vs (304±30)HU](P < 0.05), CT attenuation values of residual defects and late enhancement were also significantly different from those of remote myocardium [(360±75) HU vs (90±37) HU and (152±23) HU vs (190±37) HU, repectively](P < 0.01, P < 0.05). The mean infarction volume was (8.9± 1.0)% on MSCT and (9.2±1.4)% on TTC pathology images. The infarction volume assessed by MSCT compared well with TTC staining slices. Conclusion Acute reperfused myocardial infarction zone has specific enhancement pattens different to remote normal zone on dual phase MDCT, which is in good agreement with in vivo Trc pathology in the assessment of acute reperfused myocardial infarction shortly offer reperfusion.