Regional MR imaging enhancement of myocardial infarcts correlated with histopathologic evidence of vascular abnormality

This paper investigates the relationship between histopathologic and MR findings during the evolution of myocardial infarction. A new intravascular MR contrast medium, Gd-DTPA polylysine (0.05 mmol/kg), was injected into rats with various stages of myocardial infarction (acute = 1, subacute = 10, chronic = 120 days, n = 9 per group). MR images (TE = 20, TR = 250 msec) were acquired before and for 60 minutes after injection. Hearts were histopathologically evaluated. Prior to injection, there was no significant difference in signal intensity (SI) between normal and infarcted myocardium in acute and subacute infarcts. In chronic infarcts, SI of scar (0.16 ± 0.01) (P < 0.05)