Detection of myocardial infarction in dogs by contrast enhanced sequential CT scans

Surgically induced myocardial infarcts were studied in ten dogs by contrast enhanced computer transmission tomography at several stages of the infarct evolution. The hearts were scanned sequentially at 3.4 second intervals during intravenous bolus injection of contrast medium and every five minutes following the completion of a ten minute contrast medium infusion. Cardiac borders including those of the infarctions were defined by computer graphic techniques. Data from several consecutive scans were combined into one image; the ventricular chamber boundaries and those of the epicardium were reconstructed from images taken during the bolus injection. Images taken during the contrast medium washout phase were used for infarct area determination. A statistical definition of the boundary between normal tissue and infarcted myocardium was obtained which correlated well with autopsy measurements. Image analysis as described here may serve as a basis for infarct volume estimates as well as differentiation between acute and chronic infarctions.