Cardiac Magnetic Resonance Imaging Evaluation Of The Preliminary Experimental Study Of Cardiac Structure, Function And Myocardial Viability

Objectives To study the correlationships between dimensions of left ventricle and atrium by CMR and by ultrasonic cardiography(UCG).To evaluate the role of assessing the right ventricle dimensions by CMR.Materials and Methods A total of 36 healthy volunteers were examined with fast imaging employing steady-state acquisition(FIESTA) cine MR sequence.And all the MR images were dealed on ReportCard software.UCG was also performed in all the volunteers.The correlationships were determined with the dimensions of left ventricle and atrium by CMR and by UCG.Results CMR results:interventricular septum:9.2±2.1mm,left ventricle posterior wall thickness:8.0±2.1mm,end diastolic dimension of left ventricle:48.6±5.5mm,end systolic dimension of left ventricle:30.3±5.3mm,left atrial dimension:32.2±5.3mm,aortic root dimension:28.5±3.5mm.Interventricular septum,left ventricle posterior wall thickness,end diastolic dimension of left ventricle, end systolic dimension of left ventricle,left atrial dimension and aortic root dimension by CMR all correlated with those by UCG(r=0.843,p＜0.01,r=0.784,p＜0.01; r=0.686,p＜0.01;r=0.730,p＜0.01;r=0.675,p＜0.01;r=0.557,p＜0.01).Major dimension of right ventricle:69.2±9.7mm;Minor dimension of right ventricle: 30.6±6.6mm;RV major axis index:39.4±5.5mm/m^2;;RV minor axis index:18.1±3.4 mm/m².Conclusions The present study suggests that cine MR imaging is well applicable for left and right ventricle dimension evaluation. Objectives To study the correlationships between LVEF by CMR and other different methods.To evaluate the role of assessing the right ventricle dimensions and the ventricular function by CMR.Materials and Methods A total of 36 healthy volunteers and 22 old myocardial infarction(OMI) patients were examined with fast imaging employing steady-state acquisition(FIESTA) cine MR sequence. And all the MR images were dealed on Report Card software.UCG was performed in all the volunteers and OMI patients.Coronary CTA was also performed in OMI patients.Measure the LVEDV,LVESV,RVESV,RVEDV and calculate the LVEF and RVEF in all the volunteers and OMI patients.Analyze he correlationships between LVEF by CMR and by ultrasonic cardiography(UCG),LVEF by CMR and by coronary CTA.Results CMR results in volunteers:LVEDV:93.6±17.2ml,LVESV: 39.5±13.0 ml,LVEF:58.5%±8.19%,RVEDV:108.6±28.2ml,RVESV:45.6±15.1ml,RVEF:58.2%±7.4%.LVEF(58.5%±8.19%) in volunteers by CMR has correlation with LVEF(64.1%±6.8%) by UCG.CMR results in OMI patients: LVEDV:114.4±38.9ml,LVESV:64.5±35.9ml,LVEF:46.5%±12.3%,RVEDV: 123.4±19.0ml,RVESV:50.6±12.6ml,RVEF:59.2%±5.9%.LVEF(46.5%±12.3 %) in OMI patients by CMR correlated with LVEF(52.3%±10.4%) by UCG(r= 0.72,p＜0.01) and LVEF(45.6%±10.2%)by coronary CTA(r=0.853,p＜0.001). Objectives The aim of this study was to investigate the feasibility and accuracy of the ceMRI to detect the viable myocardium to detect viable myocardium. Materials and Methods Analyze the transmural ratio with ceMRI and UCG results of 22 OMI patients.Analyze the TIMI results and SPECT myocardial viability of 13 OMI patients.In all different methods the left ventricle was divided into 17 segments. Determining the accuracy of the ceMRI by receiver operating characteristic curve(ROC) analysis and kappa analysis.Results The area under the curve(AUC) of transmural ratio with ceMRI was 0.953 and AUC of TIMI was 0.935.The sensitivity and specificity of transmural ratio 26%-50%to detect viable myocardium were 88.9% and 82.7%respectively.The sensitivity and specificity of transmural ratio 51%-75% to detect viable myocardium were 74.1%and 98.7%respectively.The transmural ratio with ceMRI was consistent with ventricular wall motion abnormality with UCG (kappa=0.769,p＜0.01).Conclusions Contrast-enhanced MRI can clearly display the location,dimension and extention of myocardial infarction.The accuracy of the ceMRI to detect viable myocardium was very high. Objectives To study the accuracy of ceMRI for identifying necrotic myocardium in acute myocardial infarction animal models and assessing the curative effect.Materials and Methods Acute myocardial infarction animal models were made by ligation of LAD in 14 pigs.14 pigs were divided into 2 groups at random. Experimental group was injected by ligustrazine at the 1^st,3^rd,5^th,10^th d atter AMI. Control group was injected by sodium chloride at the same time.At the 3^rd and 30^th d, all pigs underwent ceMRI scan.After one month of AMI,TTC stain was done.ceMRI imgings and TTC pictures were analyzed by Image-Pro PLUS 5.1 software. Hyperenhanced area vs.left ventricle area and infarction area from TTC vs.left ventricle area were calculated.Analyze the correlationship between these two. Independent-samples T test was used to define the change of hperenhancement area. Results In all 14 pigs,FIESTA cine MRI showed ventricular wall motion abnormality. FGRET sequence on 14 pigs showed low signal area in perfusion at the 3^rd d.But this could be seen in only 5pigs at the 30^th d.And the low signal area decreased.MDE sequence all showed transmural hyperenhanced signal.Hperenhancement area vs.left ventricle area at the 30^th d(34.9%±3.3%) had a closed correlationship with infarction area from TTC vs.left ventricle area(r=0.97,p＜0.01).The result of independent-samples T test between experimental group and control group was t= 3.682,p＜0.01.Conclusions Contrast-enhanced MRI can be used to identify the existence and the size of necrotic myocardium.And it can also monitor the curative effect in myocardial infarction.