The Value Of Cardiac Magnetic Resonance Imaging (MRI) In Assessing The Cardiac Function Of Coronary Atherosclerotic Heart Disease

Part one:Evaluation of Left Ventricular Function and myocardial viability With Echocardiography Comparison with cardiac magnetic resonance imaging techniquesObjective:The purpose of this study was to compare measurements of the left ventricular function as well as the myocardial viability obtained by magnetic resonance imaging(MRI) to those obtained by echocardiography.Methods:Twenty patients (20men, mean age56.15±8.92years old) were enrolled in this study who were diagnosed as coronary artery disease (CAD). Fourteen of them were diagnosed as acute myocardial infarction(AMI). Four of them were diagnosed as old myocardial infarction. Two were diagnosed as stable angina. All those patients underwent echocardiography and cardiac magnetic resonance imaging to measure the left ventricular ejection fraction(LVEF) and get the image of delayed-contrast enhancement(DE-MRI) by cardiac magnetic resonance imaging(CMR). The relativity and comparability of the LVEF in echocardiography and CMR were measured.Results:The LVEF detected by echocardiography was0.59±0.16, while the LVEF detected by CMR was0.45+0.14. There was statistically significant between the difference(r=0,827, P<0.05). Defined the echocardiography as the gold standard test. The sensitivity, specificity, positive predictive value and negative predictive value of CMR when measure LVEF were100%,66.7%,50%and100%. Eighteen patients with infarction history as well as two patients with stable angina were detected delayed enhancement by CMR. Nine of fourteen patients with AMI were found oedema in myocardium. Among these twenty patients, seven of them were detected abnormal wall motion while one of them were found ventricular aneurysm by both echocardiography and cine-MRI. Eight of twenty patients were detected mild mitral regurgitation while thirteen of them were found mild tricuspid regurgitation by echocardiography, but no specific finding was found by CMR.Conclusions:The LVEF assessed by CMR was lower than that measured by echocardiography. Both of them have relativity with statistical significant difference. Undetected myocardial necrosis and oedema myocardium can be observed by CMR. Part two:The diagnose value of CMR to speculate the narrow coronary artery compared to quantitative coronary angiographyObjective:The purpose of this study was to assess the diagnosis value of the delayed-enhanced MRI compared to coronary angiography(CAG) in the measurement of narrow coronary artery.Methods:There were twenty patients enrolled in this study who diagnosed as coronary artery disease (CAD). All those patients underwent delayed-enhanced MRI(DE-MRI) and coronary angiography. Define the significant luminal stenosis as equal or greater than70%, Calculate the sensitivity and specificity of the DE-MRI.Results:Define the significant luminal stenosis as equal or greater than70%. Calculate the sensitivity and specificity of the DE-MRI. There were12LADs,7LCXs,12RCAs detected to be significant stenosis by quantitative coronary angiography(QCA). There were8LADs, I3LCXs,13RCAs detected to be stenosis less than70%by QCA.Calculation of the sensitivity was77.42%, and the specificity was93.10%, and the positive predictive values and the negative predictive values were92.31%and79.41%. Two of twelve patients who underwent primary PCI were found strip low signal on DE-MRI. Conclusions:DE-MRI showed high specificity and positive predictive values and the patients with significant luminal stenosis. Strip low signal were found on DE-MRI which may indicate no-flow phenomenon.