Usefulness of ultrafast magnetic resonance imaging in healed myocardial infarction.

The value of ultrafast magnetic resonance imaging (MRI) in the assessment of dynamic contrast enhancement and myocardial perfusion abnormalities was evaluated in 20 patients with healed myocardial infarction, who also underwent 2-dimensional echocardiography. At baseline and after bolus injection of the paramagnetic contrast agent gadolinium-diethylenetriaminepentaacetic acid (DTPA) (0.04 mmol/kg body weight), single-level short-axis MRI was performed every third RR interval with an acquisition time of 500 ms. Myocardial signal intensities were measured in transmural myocardial regions of interest. After gadolinium-DTPA injection, infarcted and normal myocardium demonstrated a signal intensity enhancement of 50 and 134%, respectively (p < 0.001). A signal intensity of normal relative to infarcted myocardium increased from 1.25 +/- 0.22 (SD) before to 1.91 +/- 0.41 after gadolinium-DTPA (p < 0.001). The rate of signal increase in the infarcted and normal myocardium was 5.17 +/- 2.22 and 18.99 +/- 9.96 s-1 (p < 0.001), respectively. Ultrafast MRI using gadolinium-DTPA bolus administration clearly identifies myocardial perfusion abnormalities in patients with healed myocardial infarction. The infarct site on MRI corresponded with the location of wall motion asynergy determined by echocardiography. It is concluded that gadolinium-DTPA-enhanced ultrafast MRI provides noninvasive assessment of myocardial perfusion in patients with proven coronary artery disease.