COMPUTER - ASSISTED TOMOGRAPHY The usefulness of x - ray computed tomography for the diagnosis of myocardial infarction

Conventional and enhanced computed tomographic (CT) examinations were performed in 103 patients with myocardial infarction for evaluation of the diagnostic usefulness of CT. After intravenous bolus injection of contrast material, an initial filling defect and late enhancement of the infarcted myocardium appeared on the cardiac CT images. These two findings were direct evidence of myocardial infarction; the former was found mostly in the patient with recent myocardial infarctions, and the latter was recognized both in those with recent and those with "remote" infarctions. Wall thinning at the site of infarction was found by enhanced CT mostly in patients with anteroseptal or extensive anterior infarctions, and was rarely found in patients with inferoposterior infarctions. Left ventricular aneurysms and ventricular thrombi were found by enhanced CT in 39 and 23 of the 103 subjects, respectively, and the sensitivity of CT in detecting intracardiac thrombi was higher than that of two-dimensional echocardiography. Calcification of the myocardium and pericardial effusion associated with myocardial infarction were also detected by conventional nonenhanced CT. Thus, cardiac CT was found to be a useful test in evaluating patients with myocardial infarction. Circulation 70, No. 2, 217-225, 1984. RECENTLY x-ray computed tomography (CT) has been validated as a useful noninvasive diagnostic method for use in patients with various cardiac diseases. As far as the application of CT in patients with myocardial infarction is concerned, since the report by Adams et al. ,' which demonstrated that the CT findings in infarcted myocardium differed from those in normal myocardium whether or not contrast enhancement was used, the possibility of detection of myocardial infarction and of evaluating its extent and the stage by this technique has drawn much interest. To date there have been many reports of the CT findings in animals with experimentally produced infarction.2 6 Several studies reported that the infarcted myocardium appeared as an area of poor enhancement on the x-ray during the first few minutes of the intravenous administration of contrast material.", 1016 Subsequently there was a greater degree of enhancement of the infarcted area compared with the normal myocardium. This phenomenon was called late enhancement of the myocardium and it was noted to be persistent for From the Third Clinical Department of Internal Medicine, Chiba University School of Medicine, Chiba, Japan. Address for correspondence: Dr. Yoshiaki Masuda, The Third Clinical Department of Internal Medicine, Chiba University School of Medicine, 1-8-1 Inohana, Chiba City 280, Japan. Received Aug. 15, 1983; revision accepted April 5, 1984. Vol. 70, No. 2, August 1984 several minutes to 1/2 hr after the injection of contrast