MYOCARDIAL-CELL DEATH IN REPERFUSED AND NONREPERFUSED MYOCARDIAL INFARCTIONS - MR-IMAGING WITH DYSPROSIUM-DTPA-BMA IN THE PIG

Purpose: To investigate whether Dy-DTPA-BMA-enhanced MR imaging would permit identification of myocardial cell death, myocardial infarction was induced in 12 domestic pigs. Material and Methods: In 6 pigs with irreversible cell damage, Dy-DTPA-BMA (1.0 mmol/kg b.w.) was administe red i.v. 70 min after coronary occlusion. In 6 other pigs, the infarct ions were reperfused 80 min after the occlusion, followed by injection of Dy DTPA-BMA after 30 min of reperfusion. In 4 additional pigs, the hearts were reperfused after 2 min of occlusion. All 16 pigs were sac rificed 10 min after the injection of Dy-DTPA-BMA. The hearts were exc ised and imaged with MR. Results: Reversibly injured myocardium could not be distinguished from adjacent nonischaemic myocardium after the a dministration of Dy-DTPA-BMA. Reperfused, infarcted myocardium demonst rated a high signal intensity in the proton-density- and T2-weighted s equences, despite a 5-fold higher Dy concentration compared with both nonreperfused infarcted and nonischaemic myocardium. Conclusion: This lack of susceptibility effect in infarcted myocardium, due to a homoge neous distribution of Dy, indicates the usefulness of Dy as a marker o f tissue viability.