The Study Of CMRI First-pass Perfusion And Delayed Enhancement Imaging Assessment Myocardial Viability After MI

Objectives:Discussing the clinical value of 3.0T cardiac magnetic resonance imaging to assessment myocardial viability in patients with acute myocardial infarction.Myocardial infarction in patients with MR first-pass myocardial perfusion imaging, DE-MRI and cardiac cine scan. Understanding the changes in myocardial perfusion images, perfusion curve, DE-MRI and cardiac function.To investigate microvascular disease after myocardial infarction assessment activity of myocardial infarction and MR imaging and to discuss myocardial infarction transmural extent of integration,integration of myocardial perfusion,coronary Gensini score,infarct size impact on cardiac function.Methods:1.Collecting the Second Affiliated Hospital of Kunming Medical University of July 2014-December 2015 myocardial infarction in 30 patients,18 males and 12 females,10 cases of asymptomatic normal as controls. All the patients with myocardial infarction before the PCI underwent 3.0T MRI, ECG and enzyme examination,The main techniques include magnetic resonance imaging scan cardiac morphology,cardiacfunction,myocardialviability,myocardialperfusionimaging.Respect ively myocardial infarction patients and normal control group underwent MR first-pass myocardial perfusion imaging and DE-MRI scans, according to characteristic of myocardial perfusion image, the perfusion curve,left ventricular 16-segment perfusion is divided into normal, reduced perfusion and myocardial perfusion defect segments,to understand the types and distribution of myocardial infarction in patients with myocardial perfusion segments. By comparing segments of myocardial infarction in patients with myocardial infarction, the relative peak signal and the maximum rise slope around the MI segment myocardial injury and normal control group perfusion curve segment of semi-quantitative analysis and comparison,Comparing myocardial infarction segmental infarction, myocardial segments around the injury with the normal control group of normal myocardial perfusion peak signal segments whether there have significant differences.2.Selecting single vascular disease in 10 patients with myocardial infarction, underwenting MR first-pass myocardial perfusion imaging and DE-MRI scans, according to characteristic of myocardial perfusion image, the perfusion curve,left ventricular 16 segments perfusion is divided into normal, reduced perfusion and myocardial perfusion defect segments,to understand the types and distribution of myocardial infarction in patients with myocardial perfusion segments.By semi-quantitative analysis and comparison is there a difference between normal perfusion, reduced perfusion, perfusion defect area perfusion peak signal and the maximum rising slope of the curve. According to the MRI performance, the scanning range of left ventricular 16 segments are divided into infarcted segments and non-infarcted segments. To understand the types and distribution of myocardial infarction in patients with myocardial perfusion segments, comparing with the results of first-pass myocardial perfusion MR imaging, whether there have differences in the number and distribution of different types of myocardial segments.3. Performing MR first-pass myocardial perfusion imaging and DE-MRI scan in Myocardial infarction patients. According to transmural extent of myocardial infarction is divided into five grades.0 garde is normal;Grade I transmural extent of 0-25%; Grade II transmural extent of 26-50%; Grade Ⅲ transmural extent of 56-75%; Grade Ⅳtransmural extent of 76-100%. According to the type of perfusion is divided into three grades:normal perfusion, reduced perfusion, perfusion defect. Finding out whether there are different degrees of rank correlation between transmural perfusion with different types and there have significant differencesbetween different levels of transmural perfusion with different types or not.4. Comparison of cardiac function (EF value) whether there is a correlation between myocardial infarct size, the extent of myocardial infarction through the wall of integration, integration of myocardial perfusion, coronary Gensini score or not.Results:1.30 cases of acute myocardial infarction after myocardial infarction within two weeks performed CMR scan results suggest:CMR first-pass perfusion abnormalities segments are 278. Reduced perfusion segments are 173. Perfusion defect segments are 105. DE-MRI found that the number of segments infarction section are 202.10 cases of normal control group found no positive results. Myocardial infarction segment of first-pass perfusion peak signal<normal myocardial segment, Myocardial infarction segments maximum rise slope<normal myocardial segments; Myocardial infarction damage surrounding first-pass perfusion peak signal <normal myocardial segments, Myocardial infarction damage surrounding maximum rise slope<normal myocardial segments.2. Selecting 10 cases of single vascular disease with severe stenosis or occlusion of myocardial infarction, within two weeks preformed CMR scan results suggest:CMR first-pass perfusion abnormalities segments are 70. Reduced perfusion segments are 49. Perfusion defect segments are 21. DE-MRI found that the number of segments infarction section are 36. MR first-pass myocardial perfusion abnormalities number of segments section> DE-MRI found that the number of segments of myocardial infarction section; Relative peak signal normal perfusion area> perfusion to reduce the area> perfusion defect area; maximum rise slope normal perfusion area> perfusion to reduce the area> perfusion defect area.3. The perfusion among different levels of transmural myocardial perform kendall rank correlation analysis, kendall rank correlation coefficient is 0.712. The perfusion among different levels of transmural have existence myocardial rank correlation; relative peak signal and the maximum rise slope of different levels of transmural myocardial perform One-Way ANOVA analysis (P<0.05). The difference was statistically significant. LSD-t test comparison results are shown:With the transmural extent increasing, the lower myocardial perfusion, the smaller the maximum rise slope. But for the patients of transmural extent> 50%, there have no significant difference between myocardial perfusion relative peak signal and the maximum rise slope.4. Cardiac function (EF value) has a negative correlation with myocardial infarction infarct area and myocardial perfusion points.Conclusions:1. Cardiac MRI imaging techniques can accuratly evaluate infract myocardium,myocardialviability and microvascular obstruction(MVO),whichare essential for patients with acute myocardial infarction (AMI) including dangerous degree classification, treatmentdecisions making, evaluation of therapeutic effect and prognosis evaluation.2. MR first-pass myocardial perfusion abnormalities range greater than the range of myocardial infarction. AMI patients has existed ischemic injury but viable myocardium around myocardial infarction. First-pass perfusion relative peak signal and the maximum rise slope has decreased. On DE-MRI show no high signal or show slightly higher signal,but the brightness significantly lower than myocardial infarction.Which Indicate myocardial ischemia injury but can survive myocardium.3. MR first-pass myocardial perfusion imaging combined with DE-MRI can be used for assessment myocardial ischemic injury but can survive myocardium. Correct and effective assessment of ischemic but viable myocardium for acute myocardial infarction patients whether need revascularization and,blood supply recovery of patients with myocardial infarction after treatment and heart function recovery, which can provide important clincial value.4. The larger the area of myocardial infarction,the worse the heart function has. It is showed that microcirculation and myocardial infarction area have influence on cardiac function.