Development of Parametric Imaging of Myocardial Perfusion Using Ultrasonic Microbubble Destruction

我们设计了一种新的间歇性成像，采用超声脉冲序列，利用超声微泡破坏定量心肌血流量（MBF），我们设计了一种新的间歇性成像，采用超声脉冲序列，利用超声微泡破坏定量心肌血流量（MBF）。我们发现，在静脉注射微泡造影剂的心肌声学造影中，超声脉冲间隔（PI）的突然缩短使造影强度（CI）沿着帧数（f）衰减，其衰减函数为SI=α×exp（-β×f）+γ。我们使用流动模型进行的体外研究表明，由此获得的α和β反映了流动通过速度。随后，我们进行了一项体内研究，其中大鼠MBF成功地定量与新的参数来自这个公式。通过定义心肌速度为Vel=1/（β/HR），其中HR为心率，心肌血容量为Vel =α+γ，MBF确定为Vel ...更多信息 = [1/（β/HR）]（α+γ）。因此，MBF测定表现出密切的相关性与微球衍生MBF在基线，在药理学充血，冠状动脉stenoes.Finally，我们验证了这种方法在临床环境中。利用谐波能量多普勒和市售微泡获得的参数进行临床应用，我们检查了脉冲序列的有用性。在静脉微泡输注期间，由PI从1：10缩短到1：1收缩末期ECG触发产生的CI衰减程度表现出类似的衰减。CI衰减程度：α/（α+γ）可用于冠状动脉血管舒张功能储备的定量，其灵敏度为93%，特异性为85%。此外，发现发射4个快速脉冲的多帧触发器可用于标准化心肌中的微泡浓度。从团注微泡造影剂后心肌节段性显影开始到最后一次脉冲未显影的时间与心肌血容量相关，因此在住院患者的梗死节段中通过201-铊摄取来评价心肌存活性。少

We devised a new intermittent imaging employing an ultrasound pulsing sequence that utilized ultrasonic microbubble destruction to quantitate myocardial blood flow (MBF).We devised a new intermittent imaging employing an ultrasound pulsing sequence that utilized ultrasonic microbubble destruction to quantitate myocardial blood flow (MBF). We found that abrupt shortening of ultrasound pulsing interval (PI) in myocardial contrast echocardiography during intravenous microbubble infusion produces a decay of contrast intensity (CI) along frame number (f), which fit tell to a decay function SI=α×exp(-β×f)+γ. Our study in vitro using a flow model revealed that α and β thus obtained reflect flow transit velocity. Subsequently, we performed an in vivo study in which MBF in rats was successfully quantitated with the new parameters derived from this formula. By defining myocardial velocityas Vel=1/(β/HR), where HR is heart rate, and myocardial blood volume as Vol=α+γ, MBF is determined as VelxVol … More = [1/(β/HR)](α+γ). MBF thus determined exhibited a close correlation with microsphere-derived MBF at baseline, during pharmacological hyperemia, and during coronary stenoses.Finally, we validated this method in clinical settings. The parameters obtained with harmonic power Doppler and commercially available microbubbles for clinical use, we examined the usefulness of the pulsing sequence. The extent of CI decay produced by PI shortening from 1:10 to 1:1 end-systolic ECG trigger during intravenous microbubble infusion exhibited a similar decay. The extent of CI decay:α/(α+γ) was found useful in quantification of coronary vasodilator reserve, which allowed defection of significant coronary stenoses with a sensitivity of 93 % and a specificity of 85%. In addition, multi-frame trigger that emitted a burst of 4 rapid pulses was found useful in standardizing microbubble concentration in the myocardium. The time duration from the beginning of segmental myocardial opacification after bolus microbubble injection to the burst in which the last pulse resulted in no opacification was correlated with myocardial blood volume, and thus the myocardial viability evaluated by 201-thallium uptake in infarcted segments inpatients. Less