Optimal acquisition parameters for contrast enhanced magnetic resonance imaging after chronic myocardial infarction

The aim of this study was to simplify the imaging of myocardial infarction based on theoretical aspects and patient variables and to define the optimal time for image acquisition. Thirteen patients with chronic myocardial infarction underwent magnetic resonance imaging. After injection of 0.2 mmol/kg body weight Gd-DTPA an inversion recovery turbo gradient echo sequence with different prepulse delays was applied every 3 to 5 minutes within an interval of 3 to 30 minutes. As parameters of investigation, the area of signal enhancement and the contrast between enhanced and nonenhanced myocardium were used. There was no influence of prepulse delay or time after contrast injection on the enhanced area. The contrast between enhanced and normal myocardium showed a peak at 6 minutes post Gd-DTPA injection and remained high. The contrast between blood and enhanced myocardium was best at 6 and 25 minutes with best intra- and interobserver variability. In conclusion, if a suitable contrast was achieved, the area of enhancement is independent of prepulse delay or imaging time. In most patients the highest contrast between blood, enhanced and normal myocardium is achieved 6 minutes and 25 minutes after contrast injection.