Enhancement of injured myocardium with Gd-DTPA: Evaluation of circulation time and MR imaging parameters

The authors evaluated the effect of Gd-DTPA circulation times and MR imaging parameters on tissue contrast in normal and injured canine myocardium after 4 hours of coronary artery occlusion. Regardless of repetition time, contrast agent enhancement was observed at echo times (TE) of more than 68 msec after 5, 30, or 60 minutes of Gd-DTPA circulation. The ratio of signal intensity in normal myocardium in the Gd-DTPA group to signal intensity in normal myocardium in the corresponding control group decreased with longer TE. After Gd-DTPA administration, enhanced tissue contrast with T2-weighted spin-echo pulse sequences is observed and occurs primarily as a result of Gd-DTPA effect on normal rather than injured myocardium