Serial nuclear magnetic resonance imaging in acute myocardial infarction.

R ecent studies show that proton nuclear magnetic resonance (NMR) imaging can detect myocardial ischemia and acute myocardial infarction (AMI) in animal models’-” and in humans.“m6 The area of AM1 appears as increased signal intensity on the spin-echo NMR images and most likely reflects the regional edema associated with tissue necrosis.’ Thus, the time course of regional edema and the evolution of infarct healing may be revealed by serial NMR studies. In a recent canine study, Pflugfelder et al7 examined the time course of the increased NMR signal intensity associated with AMI. They found that the relative signal intensity increased between the day of AM1 and 2 weeks after AM1 and subsequently decreased by the 20th day. We examined the early time course of NMR changes in humans.