Single-Dose Gadoterate Meglumine for 3T Late Gadolinium Enhancement MRI for the Assessment of Chronic Myocardial Infarction: Intra-Individual Comparison with Conventional Double-Dose 1.5T MRI

Objective: To intra-individually compare 3T magnetic resonance (MR) images obtained with one dose gadoterate meglumine to 1.5T MR using conventional double dose for assessment of chronic myocardial infarction. Materials and Methods: Sixteen patients diagnosed with chronic myocardial infarctions were examined on single-dose 3T MR within two weeks after undergoing double-dose 1.5T MR. Representative short-axis images were acquired at three points after administration of gadoterate meglumine. Contrast-to-noise ratios between infarcted and normal myocardium ($CNR_{infarct-normal}$) and between infarct and left ventricular cavity ($CNR_{infarct-LVC}$) were calculated and compared intra-individually at each temporal scan. Additionally, two independent readers assessed relative infarct size semi-automatically and inter-observer reproducibility was evaluated using intraclass correlation coefficient. Results: While higher $CNR_{infarct-normal}$ was revealed at single-dose 3T at only 10 minutes scan (p = 0.047), the $CNR_{infarct-LVC}$ was higher at single-dose 3T MR at each temporal scan (all, p < 0.05). Measurement of relative infarct size was not significantly different between both examinations for both observers (all, p > 0.05). However, inter-observer reproducibility was higher at single-dose 3T MR (all, p < 0.05). Conclusion: Single-dose 3T MR is as effective as double-dose 1.5T MR for delineation of infarcted myocardium while being superior in detection of infarcted myocardium from the blood cavity, and provides better reproducibility for infarct size quantification.