无创左室心肌声学造影的实验研究

自犬外周静脉注入以氟碳气体改良的声学造影剂（１．５ｍｌ／次）观察左心声学显影效果。结果：２条犬共１０次注射过程中均见右、左心室依次显影。左室显影４～９个心动周期后左室心肌显影并持续约８０～９５个心动周期。左室心肌显影后，左室短轴观后壁回声明显衰减。结论：经静脉注射自制改良声振白蛋白微泡可实现无创左室心肌声学造影，但其远程回声衰减问题有待进一步克服     

经静脉实时心肌声学造影对犬正常心肌灌注的定量评价

目的：探讨实时心肌声学造影定量评价犬正常心肌灌注的可行性。方法：20只开胸犬以5ml/min和10ml/min速度静滴“全氟显、进行实时心肌声学造影，左室乳头肌短轴观察左室心肌显影效果和室壁运动，闪烁显像观察心肌灌注，动态图像单帧转化后以图像软件分析造影结果。结果：静滴速度10ml/min时，心脏各部位显影时间短于5ml/min，闪烁显像时心肌再灌注速度也略快，心肌显影稳定后二者间视频亮度峰值无明显差异，均可看到舒张期／收缩期的时相性变化，同时室壁运动显示良好。结论：实时心肌声学造影可同时观察心肌灌注和室壁运动，闪烁显像可观察心肌再灌注过程，但缺少联机分析软件限制了造影结果的分析。     

实时心肌声学造影的仪器设置与显像效果的影响因素

目的：探讨实时心肌声学造影的仪器设置及显像效果的影响因素。方法：8只开胸充微量注射泵静脉滴注氟碳类造影剂全氟显（速度为5ml/min和10ml/min)进行实时心肌声学造影。调节仪器设置如增益,量程及深度等参数,于左室乳头肌水平短轴切面观察心肌显影的不同效果。结果：实时心肌声学造影可同时显示心肌血流灌注和室壁运动,除降低接受增益至50％,使用默认的仪器设置即可获得良好的造影效果,闪烁显像时最佳闪烁帧数为5个。结论：实时心肌声学造影易于掌握,影响因素较少,可同时观察心肌灌注和室壁运动,闪烁显像具有定量评价心肌血流灌注的潜力。     

实时心肌声学造影评价正常犬心肌血流灌注的实验研究

目的：应用实时心肌声学造影评价正常犬的心肌血流灌注。方法：8只开胸犬以微量注射泵静脉滴注全氟显（速度为5ml/min和10ml/min）进行实时心肌声学造影。乳头肌水平短轴切面观察左室各壁的造影效果和室壁运动。以闪烁显像观察左室各壁的再注情况。结果：实时心肌声学造影良好地显示了犬正常心肌的血流灌注特点,包括色彩、亮度与灌注时间,同时各室壁节段运动显示良好,回放测量与M型测值无明显差异,闪烁显像准确反映了心肌血流灌注的速度。结论：实时心肌声学造影可同时观察心肌灌注和室壁运动,“闪烁”显像具有定量评价心肌血流灌注的潜在价值,具有良好的应用前景。     

静脉声学造影观察肾脏血流灌注的初步实验研究

为探讨经静脉途径声学造影技术评价肾脏血流灌注的可行性，采用间断触发谐波成像技术观察自制氟碳造影剂经实验犬外周静脉注射后肾脏二维超声造影效果。结果表明：３条犬共６次声学造影均见肾脏显影（成功率１００％），其造影作用自造影剂注射后３０～５０秒开始，持续约２５～４０秒消失。结论：静脉声学造影技术可定性肾脏血流灌注，如能进一步结合造影时间－强度曲线参数有望定量肾脏血流灌注     

实时心肌声学造影定量评价不同程度心肌缺血的实验研究

目的：探讨实时心肌声学造影定量诊断不同程度心肌缺血的可行性。方法：12只开胸犬以冠脉缩窄器造成左前降支轻，中，重不同程度狭窄，狭窄前后静滴“全氟显”（速度5ml/min)进行实时心肌声学造影。左室乳头肌中段短轴观察左室前壁心肌显影，室壁厚度和运动，采用动态图像单帧转化法以图像软件分析造影结果。结果：轻度缺血时，心肌显影的视频亮度峰值（VBP）及再灌注速度与狭窄前比较无显著差异，药物负荷状态下差异增大；中，重度缺血时二者明显减低。心肌缺血时，舒张期与收缩期VBP比值正常减低。结论：结合药物负荷，实时心肌声学造影可以定量诊断不同程度心肌缺血。     

间歇谐波成像克服心肌声学造影中的远程衰减

目的　评价间歇谐波成像技术（ＩＨＩ） 在克服静脉心肌声学造影远程衰减方面的价值。方法　分别于前降支结扎前、结扎后以及重新开放状况,用ＩＨＩ 技术于左室短轴观观察经犬静脉心肌声学造影效果。结果　基础状态造影１２ 次均见左室心肌满意显影;结扎前降支后重复静脉声学造影４ 次均见左室前壁声学造影缺损,而重新开放前降支后的４ 次造影均见原声学造影缺损区重新显影。全部造影过程中左室后壁充盈良好。结论　经静脉注射自制氟碳造影剂可用于评价心肌血流灌注,而ＩＨＩ 技术的应用可较好克服远程回声衰减问题。     

静脉输注国产声学造影剂定量心肌血流灌注的实验研究

目的：评价应用国产左心声学造影剂“全氟星”定量心肌血流灌注的可行性。方法：建立犬前降支缺血模型，经外周静脉持续匀速输注“全氟星”，存取不同触发间隔的造影图像，通过计算造影剂再充填曲线的平台声强度及微泡再充填速率估测心肌血流量。以正常区为参照、放射微球测定心肌血流量为“金标准”，判定应用国产左心声学造影剂定量心肌血流灌注的可行性。结果：放射微球测定心肌血流量与心肌声学造影定量结果相关良好（r=0.8913，P＜0．001）。结论：静脉均速输注“全氟显”可用于估测心肌血流量。     

心肌声学造影在冠心病诊疗中的研究进展

心肌声学造影（myocardial contrast echocardiography,MCE）是指直接经冠状动脉或外周静脉注射含微气泡的声学造影剂,当微泡通过心肌微血管床时,用二维或多普勒超声技术接收微气泡的反射信号,从而使心肌微循环显影.近年来,随新型声学造影剂的不断推出及超声显像技术的发展,使心肌声学造影取得突破性进展,运用MCE观察心肌血流灌注、评定冠脉血流储备及冠脉血运重建术后疗效等的研究不断深入,现就其在冠心病诊疗中的运用作一综述.     

心肌声学造影无创性评价X综合征患者心肌微循环

目的应用经静脉心肌声学造影,观察X综合征患者心肌微循环灌注的特点。方法选取X综合征患者10例(Ⅰ组),健康自愿者10例(Ⅱ组),采用SonoVue进行实时心肌声学造影检查,获取心尖四腔切面图像,采用声学密度定量技术测定达到峰值的最大显影强度A,曲线上升平均斜率β及A·β乘积,并绘制时间-强度曲线。结果X综合征患者心肌显影的峰值强度A与正常对照组相比无统计学差异(P>0.05),反映心肌血流速度的β值较正常对照组低(P<0.01),反映心肌血流量的A·β乘积也明显低于正常对照组(P<0.01)。结论实时心肌声学造影可定量分析X综合征患者心肌微循环灌注情况。     

静脉滴注声学造影剂定量心肌血流的方法学研究

目的：建立持续滴注声振微泡定量心肌血流灌注的方法学。方法采用不同滴注速度经犬外周静脉注射射泡造影剂,根据心肌显影效果判定最佳滴注速度。同时重点观察应用心脏程序刺激仪或自制心电解发辅助仪克服现有现声仪器心电触发间隔长度不足的效果。结果：①除0．5ml/min滴注组造影过程中偶见远场轻度衰减,其余两组显效效果佳;②应用心脏程序刺激仪或自制心电触发辅助仪可使超声仪器心电解间隔由9个心动周期稳定性延长至45个心动周期。结论：①1－2ml/min滴注组心肌显影效果好,且其所需造影剂剂量明显低于6ml/min滴注组,建议使用;②心脏程序刺激仪及自制心龟触发辅助仪均匀可有效克服现有超声仪器心电触发间隔长度不足的问题,但心脏程序刺激仪操作略繁琐,建议使用后者。     

术中冠脉血流显像技术评价急性心肌梗死犬心肌血流灌注的研究

目的探讨术中冠脉血流显像（CFI）技术观察急性心肌梗死犬心肌血流灌注的应用价值。方法18只健康开胸杂种犬于前降支分出第一对角支后约1 cm处结扎3小时建立急性心肌梗死模型。分别于结扎前、结扎3小时后应用i13L高频探头观察前降支远端及前壁心尖段心肌内血流灌注程度、血流方向,并测量心肌内冠脉血流速度,同时在以上观察时点经股静脉匀速推注造影剂（C3F8）行心肌声学造影（MCE）检查对照。结果18只犬均成功建立急性心肌梗死模型。结扎前降支3 h后,根据MCE显示前壁心尖段有无造影剂充填分为无侧支循环形成组（A组）和侧支循环形成不充分组（B组）,A组10只犬中,CFI显示60%（6/10）未见血流信号显示,40%（4/10）前壁心尖段内仅见星点状血流信号。B组7只犬中,CFI则均显示有少量血流信号,与基础状态相比,舒张期峰值血流速度（D-Vmax）、收缩期峰值血流速度（S- Vmax）及D-Vmax/S-Vmax比值均明显降低（P〈0.05）。另有1只犬MCE显示前壁心尖段造影剂充填良好,CFI亦显示丰富的血流信号,舒张期峰值血流速度（0.65 m/s）快于基础状态峰值血流速度（0.28 m/s）。结论术中冠脉血流显像技术能直观、无创、敏感地显示心肌血流灌注状态,与MCE比较,能更敏感的反映心肌血流灌注。     

心肌声学造影评价实验性顿抑心肌的微血管功能改变

目的 探讨心肌顿抑时心肌微血管功能改变以及静脉心肌学造影方法的价值。方法 制备左前降支冠脉（ＬＡＤ）不同阻断时间后再 灌注犬心肌凶模型,在不同观察时间点静脉注射含全氟丙烷声振白蛋白微泡造影剂,采用二次谐波成像和间歇发剂技术行心肌声学造影（ＭＣＥ）。由主动脉根部分别注射乙酰胆碱（ＡＣＨ）和硝酸甘油（ＮＧ）后重复ＭＣＥ并计算用药后,前二维超声上所示心肌灰阶峰值（ＰＶＩ）和峰值比值（ＰＶＩＲ）。结果（地     

心肌造影超心动图与低剂量多巴酚丁胺负荷超声心动图识别心肌梗死后存活心肌的对比研究

目的：比较心肌造影超声心动图（MCE）与低剂量多巴酚丁胺负荷超声心动图（LDDSE）评价25例心肌梗死后心肌存活性。方法：MCE采用谐频频率1．8－3．6MHz的能量多普勒模式,按1：4的比例于收缩末期触发的方式提取图像。利声显浓度为300mg/ml,采用微量输液泵于患者左肘静脉内持续输注4分钟（2ml/min）,MCE心肌灌注结果进行半定量评价：0为无显影作用,0．5为部分或不均匀显影作用,1为完全及均匀显影作用;MCE定义心肌存活性为显影作用≥0．5分,无显影作用表示无心肌存活性。LDDSE输注剂量分别为5、10、20μg/kg/min,每期3min,采用16节段划分法在每个节段的心肌搏幅进行记分：正常运动＝1分,低动力＝2分,无动力＝3分,矛盾运动＝4分。LDDSE是计分减少≥1分定义为收缩功能储备。结果：（1）MCE前后及LDDSE前与5、10μg/（kg/min）,患者血压和心率改变无明显差异;（2）总共44个梗死节段中,MCE评价存活为28节段,不存活为16节段,LDDSE评价存活为23节段,不存活19节段（与MCE相比,LDDSE的敏感性与特异性为92％、84％）;（3）MCE与LDDSE评价心肌存活性的观察一致率为87％（Kappa:0.77)。结论：MCE与LDDSE均为评价心肌存活性的好方法。     

Albunex: a safe and effective commercially produced agent for myocardial contrast echocardiography

Microbubble solutions of sonicated human serum albumin have been shown to be effective echocardiographic contrast agents free from adverse effects on coronary blood flow, left ventricular function, and systemic hemodynamics. Albunex is a commercially prepared solution of air-filled albumin microspheres prepared from sonicated 5% human serum albumin. The effects of Albunex on coronary blood flow, left ventricular function, and systemic hemodynamics, as well as contrast enhancement were evaluated in 10 open chest, anesthetized dogs. After an intracoronary injection, Albunex did not alter left atrial, left ventricular systolic or end-diastolic, or mean aortic pressures. It did not cause a coronary hyperemic response, alter left ventricular systolic thickening, or lower the peak positive left ventricular dp/dt. It did not alter these measurements even in the presence of a critical coronary stenosis. The contrast opacification produced by Albunex microbubbles was dose dependent (optimal dose range of 0.033 to 0.5 ml/kg), with attenuation occurring at higher doses. In conclusion, although Albunex provides adequate contrast enhancement, intracoronary injection of Albunex does not significantly alter coronary blood flow, left ventricular function, or systemic hemodynamics. Because of the standardized size and concentration of the microspheres, Albunex may be an ideal agent for myocardial contrast echocardiography.     

Noninvasive detection of coronary allograft vasculopathy by myocardial contrast echocardiography.

BACKGROUND: Noninvasive detection of coronary allograft vasculopathy is still challenging. To determine the accuracy of myocardial contrast echocardiography (MCE) in detecting coronary allograft vasculopathy after heart transplantation, we studied 35 asymptomatic patients (30 men, aged 46 +/- 12.7 years) with normal left ventricular function. METHODS: Patients underwent MCE with continuous contrast (perfluorocarbon-exposed sonicated dextrose albumin) administration. Images were obtained at baseline and during peak dobutamine (up to 40 mg/kg/min) with intermittent harmonic imaging. Areas failing to increase contrast enhancement during peak stress were regarded as abnormal. Coronary artery obstructions greater than 50% at angiography were considered significant. RESULTS: Seven out of 10 patients with coronary artery disease had a positive MCE and one patient with a positive MCE had no angiographically detected disease (sensitivity = 70%, specificity = 96%, accuracy = 88.6%). Agreement between the vascular territory and perfusion defects was good for the left anterior descending coronary artery (kappa = 0.56), but not for other arteries. Although 5 patients had multivessel disease, multiple perfusion defects were detected in only one patient. CONCLUSION: MCE showed good accuracy in detecting the presence of coronary allograft vasculopathy after heart transplantation; however, it failed to identify the extent of the disease.     

Determinants of myocardial hypoperfusion analyzed for the interventricular septum using power Doppler harmonic imaging with contrast echocardiography in humans: a methodologic approach for clinical practice.

BACKGROUND: To evaluate determinants of myocardial hypoperfusion using power Doppler harmonic imaging (PDHI) with myocardial contrast echocardiography (MCE) in clinical practice, a retrospective clinical study was performed comparing echocardiographic and angiographic data. Angiographic data of patients with a normal coronary angiogram (non-CAD) and symptomatic patients with low flow conditions caused by a stenosis of the left anterior descending coronary artery (LAD) or occlusion, or TIMI-II-flow in the LAD were compared with the PDHI data. METHODS AND RESULTS: In 32 patients, MCE was performed with a System Five Performance ultrasound system (GE Vingmed Ultrasound, Horten, Norway). Myocardial perfusion was semiquantitatively analyzed with the EchoPac 6.2b.134 software, bolus injection with Optison (0.35 mL with 5 mL saline flush), and continuous infusion with Levovist (400 mg/mL(-1); 3.5-5 mL/min(-1)) were performed (8 non-CAD patients, 8 CAD patients, respectively). After bolus injection, Doppler intensity (DI) kinetics showed a significant decrease of maximum DI wash-in rate (eg, apical septum [AS]: 4.9 +/- 3.3 vs 2.4 +/- 1.9 dB/s(-1)), of peak maximum DI (eg, AS: 25.3 +/- 6.3 vs 16.4 +/- 5.7 dB), and of DI determined 10 and 20 seconds after peak maximum DI (eg, AS: 22.1 +/- 4.9 vs 10.8 +/- 4.6 dB; AS: 20.4 +/- 5.3 vs 8.0 +/- 3.8 dB, respectively) using a trigger interval once every 3 cardiac cycles when normal perfused areas were compared with hypoperfused areas. During infusion coronary transit time (3.3 +/- 0.9 vs 7.0 +/- 3.6 seconds), maximum DI wash-in rate (eg, AS: 3.2 +/- 1.3 vs 1.3 +/- 0.8 dB/s(-1)) and DI-maximum plateau (eg, AS: 28.6 +/- 4.7 vs 18.3 +/- 6.4 dB) significantly decreased, respectively. CONCLUSION: Regional myocardial hypoperfusion at rest can be detected by using PDHI with MCE in clinical practice, according to a standardized methodologic protocol.     

利声显经静脉心肌声学造影评价心肌梗死后患者的心肌灌注

目的 心肌造影超声心动图（MCE）采用触发谐频能量多普勒显像模式并用静脉持续输液利声显,观察心肌梗死后患者的心肌灌注情况,方法,使用谐频频率1．8－3．6MHZ的能量多普勒模式,于心电图T波终末处,按1：4心动周期进行触发,利声显浓度为300mg/ml,采用微量输液泵将所配心肌造影剂于患者左肘静脉内持续输注4 min(2ml/min),25例心肌梗死后患者的血压和心率变化并对心肌灌注情况进行半定量分析。结果 （1）MCE前后,患者血压和心率改变无明显差异;（2）触发谐频能量多普勒显像模式并用静脉持续输液min的心肌显影效果,而后方衰减可以避免。结论 触发谐频能量多普显像并用静脉持续输注利声显,可以产生较好的心肌灌注显像效果。     

经静脉心肌声学造影技术评价ATP敏感钾通道的开放对心肌缺血的保护作用

目的：证实经静脉心肌声学造影（MCE）,能够准确的测量缺血和梗死心肌的范围,并以此技术研究ATP敏感钾通道（KATP通道）开放对缺血心肌的保护作用。方法：21条犬随机分为三组：IR组：冠脉左前降支（LAD）闭塞90min,再灌注120min.NIC组：LAD闭塞前10min,静脉给尼可地尔100μg/kg,随后给予10μg/kg/min持续静滴至再灌注结束。CLIB＋NIC组：在IR组LAD闭塞前20min,静脉给予优降糖0．3mg/kg10min,随后步骤同NIC组。各组均在闭塞前状态、闭塞后1h、再灌注2h测定血流动力学指标;用图像分析仪测量TTC染色和危险心肌范围（AAR）和梗死心肌范围（IA）;经静脉注射全氟显示MCE,在左心室中部水平摄取短轴切面图像,冠脉闭塞1h心肌灌注缺损的范围为AAR,再灌注2h心肌灌注缺损的范围为IA。结果：冠脉闭塞1h,各组心输出量（CO）较基础状态低（P＜0．01）,再灌注2h,NIC组CO与闭塞前相比明显恢复,TTC测定AAR范围：各组之间无显著性差异（P＞0．05）。TTC测量IA范围：NIC组较IR组和GLIB＋NIC组明显缩小（P＜0．01）,MCE结果显示：与TTC染色的AAR有显著的相关性（r=0.975).IR组及GLIB＋NIC组的IA范围与TTC染色的IA范围也有显著的相关性（r=0.949)。结论：KATP通道开放剂尼可地尔能使心梗范围明显减小,经静脉MCE可准确测定缺血和梗死心肌范围。