心脏磁共振检查评价心脏结构、功能及心肌活性的初步实验研究

【作者】 周璐；

【导师】 金征宇；

【作者基本信息】 中国协和医科大学 ， 影像医学与核医学， 2008， 博士

【摘要】 第一部分心脏磁共振成像评价临床患者心脏结构的实验研究目的研究心脏磁共振(cardiac magnetic imaging,CMR)电影成像评价左室室壁厚度,左室、左房和主动脉根部内径与超声心动检查结果的相关性,探讨CMR评价右室形态的作用。资料与方法应用快速稳态平衡进动序列(fastimaging employing steady-state acquisition,FIESTA)电影序列对36名健康志愿者进行CMR检查,图像经Report Card软件进行测量,与超声心动图(UCG)所测得的左室室壁厚度、左室、左房和主动脉根部内径进行相关性研究。结果CMR左室室间隔:9.2±2.1mm,左室后壁:8.0±2.1mm,左室舒张末内径:48.6±5.5mm,左室收缩末内径:30.3±5.3mm,左房内径:32.2±5.3mm,主动脉根部内径:28.5±3.5mm。CMR左室室间隔、左室后壁、左室舒张末内径、收缩末内径、左房内径及主动脉根部内径与UCG结果均呈正相关(r分别为0.843,0.784,0.686,0.730,0.675,0.557,p均＜0.01),CMR测得右室长径:69.2±9.7mm,右室短径:30.6±6.6mm,右室长径指数:39.4±5.5mm/m~2,右室短径指数:18.1±3.4mm/m~2。结论CMR是无创心脏检查方法,其电影成像技术结合标准平面定位对左右心室形态结构评价准确,可以用于心脏疾病的诊断及疗效监测。第二部分心脏磁共振成像评价临床患者心脏功能的实验研究目的用屏气快速稳态平衡进动序列(FIESTA)心脏电影成像方法测量左心室及右心室的容量并计算射血分数(EF),分别探讨CMR评价心室功能与超声心动及冠脉CTA检查结果的相关性。资料与方法应用快速稳态平衡进动序列(fast imaging employing steady-state acquisition,FIESTA)电影序列对36名健康志愿者及22名陈旧性心肌梗死(OMI)患者进行CMR检查,图像经ReportCard软件测量左室舒张末容积(LVEDV)、左室收缩末容积(LVESV)、右室(RV)EDV、RVESV,并进一步计算LVEF及RVEF,分别研究36名健康志愿者22名OMI患者CMR的LVEF与超声心动(UCG)LVEF及22名OMI患者CMR的LVEF与冠脉CTA的LVEF结果的相关性。结果36名健康志愿者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%,健康志愿者LVEF(58.5%±8.19%)与UCG的LVEF(64.1%±6.8%)呈正相关(r=0.75,p＜0.01)。22名OMI患者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%;OMI患者LVEF(46.5%±12.3%)与超声心动LVEF(52.3%±10.4%)呈正相关(r=0.72,p＜0.01),与冠脉CTA的LVEF(45.6%±10.2%)呈正相关(r=0.853,p＜0.001)。结论CMR是无创心脏检查方法,其电影成像技术评价心功能与冠脉CTA结果相关性良好,可以用于心脏疾病的诊断及疗效监测。UCG左心功能测值较CMR偏高。第三部分心脏增强磁共振成像评价临床患者心肌活性的实验研究目的分析MRI对陈旧性心肌梗死患者心肌活性的诊断价值,并与SPECT、超声心动和冠状动脉造影TIMI分级结果对比。资料与方法分析22例陈旧性(OMI)患者的增强磁共振(ceMRI)延迟强化透壁率和超声心动节段性室壁运动异常结果,和其中13例患者的冠造TIMI分级结果和SPECT心肌存活情况,所有检查方法均按心脏17节段法分析。将13例OMI患者ceMRI透壁率、冠造TIMI分级和SPECT心肌存活情况进行ROC曲线分析,将22例OMI患者ceMRI透壁率和UCG节段性室壁运动异常评分进行诊断试验的一致性分析。结果ceMRI透壁率曲线下面积为0.953,冠造TIMI分级曲线下面积为0.935,ceMRI透壁率与金标准心肌双核素显像相比,透壁率在26%—50%诊断存活心肌的灵敏度为88.9%,特异度为82.7%;透壁率在51%—75%诊断存活心肌的灵敏度为74.1%,特异度为98.7%,与心肌双核素显像相比其诊断的准确性较高。ceMRI透壁率和UCG节段性室壁运动异常评分的一致性检验kappa值=0.769,p＜0.01。结论增强MR清晰显示心肌梗死的位置、范围和程度。ceMRI透壁率诊断存活心肌的准确性较高。第四部分心脏增强磁共振成像评价猪急性心梗疗效的实验研究目的探讨增强磁共振检查(ceMRI)对急性心肌梗死动物模型检测心肌坏死的准确性及其疗效观察情况。资料与方法采用开胸结扎前降支的方法制备猪急性心肌梗死动物模型,14只猪随机分为两组,实验组在心梗后第1、3、5、10天予川芎嗪治疗,对照组予静脉注射生理盐水,心梗后第3天及第30天对14只实验动物行ceMRI扫描,于心梗后1个月行TTC病理染色,ceMRI图像及TTC大体图片均用Image-Pro PLUS 5.1图像处理软件计算延迟强化面积或梗死面积占同层左室壁面积的百分比。分析延迟强化面积百分比与TTC染色梗死面积百分比的相关性,用独立样本t检验比较实验组及对照组第30天及第3天延迟强化面积百分比的变化是否有差异。结果心脏电影序列14只猪中有6只出现梗死局部室壁运动减弱,5只出现不运动,2只出现反向运动,伴有室壁变薄,室壁瘤形成;首过灌注序列14只猪在心梗后第3天均出现灌注减低区,在第30天仅有5只仍可见首过灌注减低区,首过灌注减低区面积较前缩小。延迟扫描序列14只猪MDE图像均表现为透壁性延迟强化信号,第30天延迟强化信号占左室面积百分比(34.9%±3.3%)与TTC染色梗死面积百分比(35.2%±3.6%)相关性极高(r=0.977,p＜0.01),实验组与对照组之间延迟强化面积占同层左室面积百分比的差进行独立样本成组t检验结果t=3.682,p＜0.01。结论ceMRI多技术联合应用可以有效检查心肌缺血、坏死,并准确判断其程度和范围,ceMRI对评价心梗疗效有一定作用。更多还原

【Abstract】 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.更多还原