【作者】 张婷；

【导师】 高东梅；

【作者基本信息】 吉林大学 ， 影像医学与核医学， 2010， 硕士

【摘要】 本文应用组织同步显像技术和二维应变显像技术探讨心力衰竭患者左心室收缩同步性和心功能,为临床观察心肌运动协调性,定量评价心肌收缩功能提供了一种全新的诊断方法。随机选取28例健康志愿者和30例心力衰竭患者作为研究对象。应用3V探头同步采集心尖四腔、心尖两腔、心尖长轴切面的二维灰阶动态图像,应用三维三平面心功能测量软件测定左心室射血分数LVEF;应用3V探头在TVI条件下同时获得心尖四腔切面、心尖两腔切面及心尖长轴切面的动态图像,连续采集三个心动周期,应用三平面组织同步显像技术定量测定左心室12节段收缩期达峰值速度时间,收缩同步指数(Max-△Ts、Ts-SD);应用TVI条件下采集的三平面动态图像,将取样容积分别置于三个切面的二尖瓣瓣环处,得到6个位点的组织多普勒速度曲线,分别测定等容舒张时间(IRT)、射血时间(ET)与等容收缩时间(ICT)等时间间期指标。应用M3S探头分别采集心尖长轴、四腔、两腔切面的三个完整心动周期的二维灰阶动态图像,应用二维应变显像技术测定左心室三个心尖切面的收缩期应变及各切面应变平均值。结果如下:应用三维三平面法所测的病例组LVEF与对照组相比明显减低;病例组ICT、IRT均明显延长,ET缩短,Tei指数明显增加;心力衰竭患者收缩期达峰值速度时间较对照组明显延长,且病例组的病变节段达峰值速度时间明显高于正常节段;三个心尖切面的GLS以及左心室整体应变平均值GLS-Avg均较正常组减低;直线相关分析显示:病例组Ts-SD、Max-△Ts与LVEF之间均呈负相关;Ts-SD、Max-△Ts与Tei指数均呈正相关;Ts-SD与Max-△Ts呈高度正相关;Ts-SD、Max-△Ts与GLS-Avg呈负相关。本研究表明组织同步显像技术能够快速、直观、定量地反应心力衰竭患者左心室同步性,二维应变显像能够反映心脏的变形程度和心功能,二者联合应用,相互补充可以定性、定量评价左心室收缩功能,为临床的诊断、治疗提供了丰富的信息,具有很大的临床应用价值。更多还原

【Abstract】 Objective:In recent years, with the new echocardiography techniques quick development, especially tissue synchronization imaging (TSI) technology and two-dimensional strain (2DS) imaging technique, which provide a new approach for the evaluation of the emergence of non-synchronous nature of myocardial motion and myocardial deformation lead to the decline of cardiac function. This study was designed to evaluate left ventricular systolic asynchrony and systolic function in patients with heart failure using tissue synchronization imaging technique and two-dimensional strain imaging technique, and analyze the correlation of systolic function and synchronization index, strain and synchronization index, and evaluate the clinical value of TSI and 2DS.Methods:30 patients with heart failure (case group) and 28 healthy volunteers (control group) were selected randomly. Using 3V probe collected two-dimensional gray dynamic images of continuous three cardiac cycles from apical four-chamber view, apical two-chamber view and apical long axis view. Left ventricular end-diastolic volume ( LVEDV )、left ventricular end-systolic volume(LVESV)、left ventricular ejection fraction(LVEF)were measured by three-dimensional tri-plane cardiac function measurement software. Using 3V probe collected tissue velocity imaging dynamic images of continuous three cardiac cycles from apical four-chamber view, apical two-chamber view and apical long axis view. Time to systolic peak velocity (Ts) of 12 segments of left ventricular were recorded by using tri-plane TSI analysis software. The standard deviation(Ts-SD)and the maximum difference(Max-△Ts)of Ts were calculated based on Ts. Isovolumic contraction time (ICT), ejection time (ET) and isovolumic relaxation time (IRT) were measured using quantitative tissue velocity imaging (QTVI). Put the sampling volume on the valve ring of apical long axis view (APLAX), four-chamber view (A4C), and two-chamber view (A2C) respectively, and the motion curve of six ventricular walls were obtained. The duration of isovolumetric systolic wave, systolic S wave and isovolumetric diastolic wave were measured respectively. Tei index was calculated. Two dimension gray scale dynamic image of three continuous cardiac cycles from apical long axis view (APLAX), four-chamber view (A4C) and two-chamber view(A2C) were obtained. The valve ring and apex of left ventricular endocardium were labeled in systolic, and analyzed automatically with AFI analysis software of two-dimensional strain. Running the software, the position of each myocardial segment in region of interesting was detected with the cardiac cycle. The six left ventricular walls of three views were equally divided into basal segment, middle segment and apical segment (18 myocardial segments). The peak systolic strain of 18 myocardial segments、strain curve and the whole cardiac strain of each view were recorded by two-dimensional strain analysis software. After measurement of three views, the software will give out the bull’s eye. All statistical analyses were recorded, and analyzed by SPSS13.0 for Windows. The results were expressed by means±standard deviation, inter-group comparison was tested by t-test. The correlation between similar indicators of cardiac function was analyzed by linear correlation analysis (P<0.05: statistical significance; P<0.01: significantly statistical significance).Results:(1) The case group had significantly larger Left Ventricular End-diastolic Volume and Left Ventricular End-systolic Volume than the normal control group. The Left Ventricular Ejection Fraction was lower in case group than in the normal control group(all P<0.05).(2) Tei index, ICT, IRT in case group were significantly longer than those in control group, and ET in case group was shorter than that in control group (P<0.05). (3) Peak velocity time in case group was significantly longer than that of control group. The time to systolic peak velocity of diseased segments were significantly longer than the normal segments in case group(P<0.01).(4) The control group included 336 segments, in which 276 segments were green (82%), 60 segments were yellow moderately-delayed (18%), and no red severely-delayed segments. There were 360 segments in case group, in which 158 segments were green (44%), 72 segments were moderately-delayed (20%) and 130 segments were severely-delayed (36%). (5) The systolic strain of 18 segments in case group was significantly lower than that of control group. The average GLS and GLS of APLAX, A4C, A2C of the case group were all lower than that of the control group. The strain of control group were increase gradually from basal segment to apical segment, and there were no statistic difference in each other ventricular walls. But the strain of case group lose this law. (6)The Ts-SD and Max-△Ts were negative correlated with LVEF measured by 3D-3 plane method, the correlation coefficient were -0.468,- 0.467, (P<0.05). The Ts-SD and Max-△Ts were positive correlated with Tei index, the correlation coefficient were 0.602, 0.494, (P<0.05).The Ts-SD was highly positive correlated with Max-△Ts, the correlation coefficient was 0.916, (P<0.01). The Ts-SD and Max-△Ts were highly negative correlated with GLS, the correlation coefficient were 0.58, 0.48, (P<0.05).Conclusions:The following conclusions from the results of this study: (1) The left ventricular systolic function is decreased and cardiac wall motion is not synchronized in patients with heart failure. TSI is a non-invasive investigation, which can quantitatively and qualitatively assess the synchronization of myocardium motion, and provide a more reliable basis for select and cure patients indicating for cardiac resynchronization therapy. (2) TSI can analyze myocardial systolic asynchrony by time to systolic peak velocity. The systolic coincident indexes were correlated with Tei index and LVEF which are all assessing left ventricular systolic function index. With the decrease of synchronism in heat failure, LVEF and Tei index are all change. It was consistent with using these indexes for assessing left ventricular systolic function and synchrony. (3) Global strain long axis in patients with heart failure were significantly lower than control group, the overall ventricular strain as the cardiac function parameter, can be more accurately and quantitatively evaluate left ventricular function. The strain was negative correlated with coincident index, and it was feasible and reliable for assessing left ventricular systolic function using two-dimensional strain imaging technique.In sum, TSI can response the synchronization of myocardial qualitatively and quantitatively. Two dimensional strain can response the degree of myocardial deformation well. They are combine and replenish each other. As a new method for assessing left ventricular systolic function, it can well evaluate the movement of left ventricular in patients with heart failure. It provides an important theoretical evidence for clinical treatment, and provide a development and supplementary for conventional echocardiography.更多还原