Role of Cardiac Magnetic Resonance Imaging in Diagnosis of Myocardial Infarction

Introduction: Cardiac Magnetic Resonance Imaging provides an accurate and reproducible modality for the assessment of global ventricular volumes and function, and valuable in establishing a diagnosis of chronic and acute MI and distinguishing this condition from non-ischemic cardiomyopathies. Aim: To evaluate the role of cardiac Magnetic Resonance Imaging technique in diagnosis of myocardial infarction, assessment of myocardial viability. Subject and Method: The study was conducted over a period of 3 years at Assiut University Hospital. Fifty-six patients were recruited. All patients were subjected to full history taking and radiological evaluation using a 1.5-T MR system and echocardiography. Agreement regarding segmental wall motion was assessed by using Cohen’s Kappa statistics. Also ejection fraction measurement by both modalities was compared using bland-Altman plots. Agreement between Magnetic Resonance Imaging and conventional coronary angiography in detection of diseased coronary arteries was examined using Cohen’s kappa coefficient (κ). Results: It was found that ejection fraction detected by Echo were overestimated relative to Magnetic Resonance Imaging with statistically significant difference (p=0.004). While LV diameters detected by echocardiography were underestimated relative to Magnetic Resonance Imaging. Good agreement between Magnetic Resonance Imaging and Echo regarding segmental wall motion. There was positive very high correlation between the two modalities in evaluation of LV Functionality indices. Conclusion: CMR is superior to echo in evaluating left ventricular functionality indices with echo underestimating these indices except the ejection fraction which is overestimated by Echo. Moreover, CMR is better in evaluating post MI complications and associated cardiac abnormalities.