Computed tomographic findings in fresh (2nd to 4th week) myocardial infarction

Thirty-seven patients, 2-4 weeks after transmural myocardial infarction, were investigated with ungated CT over a period of 120 min. after an i.v. contrast medium infusion + bolus injection of 0.6-0.9 iodine/kg body mass. Perfusion defect was found in 23/33 (70%) of technically adequate studies, delayed washout in 6/33 (18%) and local deformity of LV in 8/33 (24%). The mass of the perfusion defect assumed to represent the CT infarct size had a mean value of 10.2 g (3.5-25.8), infarct size estimated with CK-MB enzyme release method had a mean value of 14.1 g eq. (2.4-28.2). There was a r = 0.95 rectilinear correlation coefficient (p less than 0.001) between the CT and CK-MB method of infarct size estimation. Infarcts of size less than 6.0 g eq could not have been demonstrated with CT as a perfusion defect. Contrast enhancement of the infarct area was not a reliable feature of infarction.