定量组织速度成像及组织追踪成像技术与MRI检查评价急性心肌梗死犬左室壁节段性运动异常的对照研究

目的:应用定量组织速度成像(QTVI)技术、组织追踪成像(TTI)技术及MRI评价犬急性心肌梗死后左室壁节段性运动异常,探讨左室局域梗死心肌的运动幅度及舒缩功能变化。方法:利用QTVI及TTI技术对8只急性心肌梗死犬冠脉结扎前、后2h扫查心尖左室长轴、心尖二腔、心尖四腔切面,将取样容积分别置于左心室基底部(Bas)、二尖瓣环水平(Mv)、中部乳头肌水平(Mid)及心尖部心内膜下(AP),同步获取上述水平各取样点在左室前壁、后壁、侧壁下壁、后室间隔及前室间隔的心肌沿长轴方向运动组织速度曲线和位移曲线,观察各节段收缩期的运动速度及位移,记录各取样点收缩期峰值速度(Vs)、收缩期峰值位移(D)及舒张早期速度峰值(Ve)变化,并对心肌梗死犬进行MRI检测,观察梗死节段心肌室壁厚度及运动幅度变化情况。将两种影像学检测结果进行对比研究。结果:冠脉结扎后急性心肌梗死犬受累节段纵向上心肌收缩期峰值速度(Vs)、收缩期峰值位移(D)均较结扎前减低(P<0.05或P<0.01),舒张早期峰值速度减低,Ve丧失正常时由心底到心尖逐渐减低的规律。MRI结果显示,广泛左心室前壁、前间壁及部分侧壁运动减弱且厚度变薄。运动减弱及心肌厚度变薄区域与左前降支供血区域一致。结论:QTVI及TT能敏感、直观、定量评价左室局域梗死心肌节段性运动情况的及舒张、收缩功能,对急性心肌梗死的早期诊断具有重要意义,并与MRI所显示梗死节段具有较好的一致性。

Control study of regional left ventricular wall motion abnormality of canine acute myocardial infarction by quantitative tissue velocity imaging,tissue tracking imaging and MRI

Objective To evaluate the segmental left ventricular wall motion abnormalities after acute myocardial infarction in dogs and changes in systolic and diastolic function of infracted myocardium with quantitative tissue velocity imaging(QTVI) technology,tissue tracking imaging(TTI) technology and MRI.Method Using QTVI and TTI technology,the apical left ventricular long-axis,apical two-chamber and apical four chamber view were csanned before and 2h after coronary artery ligation in 8 dogs with acute myocardial infarction.The sample volume was placed at the bottom of the left ventricular base(Bas),mitral annulus level(Mv),the middle level of papillary muscles(Mid) and subendocardial apical(AP),synchronous sampled to obtain the left ventricular anterior wall,posterior wall,inferior wall,and the former and post-interventricular septal cardium movement along the long axis velocity curve and the displacement curve in the above-mentioned levels,to observe the systolic movement speed and displacement of each segment,and to record peak systolic velocity (Vs),peak systolic displacement(D) and peak early diastolic velocity(Ve) changes.MRI detection was made on myocardial infarction dogs,changes of infarcted myocardial wall thickness and range of motion were observed.Detection of the two types of imaging study results were compared.Results After coronary artery ligation in dogs with acute myocardial infarction,Vs and D of affected myocardium were lower than that of preligation(P<0.05 or P<0.01),early diastolic peak velocity reduced,and Ve lost the normal law of reduce gradually from the bottom to apex.MRI results showed a wide range of left ventricular anterior wall,the former partitions and partial inferior wall with weakened movement and thinning thickness,and regions of weakened movement and thinning thickness were concordance with the regions supplied by the left anterior descending coronary artery.Conclusion QTVI and TTI can evaluate the segmental movement and diastolic,systolic function of left ventricular myocardial infarction area sensitively,intuitively,and quantitatively,shows great significance in early diagnosis of acute myocardial infarction,also has better consistency with MRI in segmental infarction.