Delayed-enhancement magnetic resonance imaging at 3.0 T using 0.15 mmol/kg of contrast agent for the assessment of chronic myocardial infarction

Objective: A recent international, multicenter, double-blinded, randomized trial shows delayed-enhanced magnetic resonance imaging (DE-MRI) using contrast doses of ≥0.2 mmol/kg is effective in the detection and assessment of myocardial infarction (MI), and 0.1 mmol/kg is not enough; intermediate doses between 0.1 and 0.2 mmol/kg have not been tested. The aim of this study was to prospectively test the performance of DE-MRI using 0.15 mmol/kg of contrast agent for the detection of MI. Materials and methods: A total of 31 consecutive patients with chronic MI underwent DE-MRI at 3.0 T using both 0.15 mmol/kg and 0.2 mmol/kg of contrast agent in random order and on separate days. Infarction segment and infarction size were compared on DE-MRI images using a 17-segment model. Bland–Altman analysis was used to analyze correlation and agreement between global infarct sizes. Results: DE-MRI showed enhanced myocardium in all the 31 patients with chronic MI. There was no significant difference between the 0.15 mmol/kg and 0.2 mmol/kg images in all 31 patients based on the infarction segment (7.87 ± 2.72 vs. 7.81 ± 2.64, respectively; p = 0.33). There was no significant difference between the infarction size obtained from 0.15 mmol/kg acquisition and that from 0.2 mmol/kg acquisition (16.3 ± 7.8% vs. 16.4 ± 7.9%, respectively; p = 0.87). A strong correlation between the infarction size obtained from 0.15 mmol/kg acquisition and that from 0.2 mmol/kg acquisition was indicated through Bland–Altman analysis. Conclusion: DE-MRI at 3.0 T using 0.15 mmol/kg of contrast agent is effective for the assessment of MI