Detection, quantitation and contrast enhancement of myocardial infarction utilizing computerized axial tomography: comparison with histochemical staining and 99mTc-pyrophosphate imaging.

The potential role of the CAT scan in detecting and quantitating acute myocardial infarctions was assessed in the excised hearts of 25 dogs with 48-hour-old myocardial infarctions. The CAT scan detected the infarct in every instance and distinguished subendocardial from transmural infarctions. While the CAT scan slightly underestimated the volume of infarcted tissue, this volume had a close linear relationship to the true volume determined by histochemical staining. On the other hand, the 99mTc-pyrophosphate scintiscans grossly overestimated the volume of infarcted tissue. Intravenous administration of contrast material prior to sacrifice produced contrast enhancement either of the rim or diffusely throughout the infarct. Thus CAT should have an important role not only in detecting but also in estimating the volume of acute myocardial infarctions.