[Diagnosis of myocardial infarction by CT: the study of an initial filling defect and late enhancement of the infarcted myocardium after injection of contrast material].
Several animal experimental studies have shown that the enhanced CT gives the direct evidence of acute myocardial infarction characterized by an initial filling defect and late enhancement in the site of the damaged myocardium. Therefore, we studied experimentally and clinically the diagnostic value of these CT findings in detecting and quantitating recent and remote myocardial infarctions. Sixteen mongrel dogs with anterior myocardial infarction were subjected to the present study. The cardiac infarction within one month after coronary arterial ligation was visualized as a filling defect by early CT scan after intravenous injection of contrast material. The delayed scan after the injection showed late enhancement of the infarcted area in both acute and chronic phases. Post mortem histologic studies confirmed that the area of filling defect coincided with the necrotic myocardium and late enhancement coincided with the totally infarcted myocardium including healed scar. The total infarct size measured from CT images was closely correlated with histo-pathological infarct volume (r = 0.96). In the clinical study, the enhanced CT was performed on 112 patients with myocardial infarction and 12 patients with angina pectoris. The filling defect and late enhancement of the infarcted myocardium in the antero-septal or apical wall were detected as clearly as in the animal experiment; the former was found in 85% of the patients with recent infarction, and the latter was detected in about a half of the patients with both recent and remote infarctions. However, these CT findings were not clearly recognized in the patients with infero-posterior infarction, subendocardial infarction or angina pectoris. These results indicate the usefulness of CT in the noninvasive diagnosis and a follow-up study of myocardial infarction.
D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D004285:Dogs; D006801:Humans; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement; D013997:Time Factors; D014057:Tomography, X-Ray Computed
D003287:Contrast Media