Fan P, Nanda N C, Gatewood R P, Cape E G, Yoganathan A P
Division of Cardiovascular Disease, University of Alabama at Birmingham 35233, USA.
Ultrasound Med Biol. 1995;21(8):1021-8. doi: 10.1016/0301-5629(95)00050-2.
Due to the unavoidable problem of aliasing, color flow signals from high blood flow velocities cannot be measured directly by conventional color Doppler. A new technology termed Quantitative Un-Aliased Speed Algorithm Recognition (Quasar) has been developed to overcome this limitation. Employing this technology, we used transesophageal color Doppler echocardiography to investigate whether the velocities detected by the Quasar would correlate with those obtained by continuous-wave Doppler both in vitro and in vivo. In the in vitro study, a 5.0 MHz transesophageal transducer of a Kontron Sigma 44 color Doppler flow system was used. Fourteen different peak velocities calculated and recorded by color Doppler-guided continuous-wave Doppler were randomly selected. In the clinical study, intraoperative transesophageal echocardiography was performed using the same transducer 18 adults (13 aortic valve stenosis, 2 aortic and 2 mitral stenosis, 2 hypertrophic obstructive cardiomyopathy and 1 mitral valve stenosis). Following each continuous-wave Doppler measurement, the Quasar was activated, and a small Quasar marker was placed in the brightest area of the color flow jet to obtain the maximum mean velocity readout. The maximum mean velocities measured by Quasar closely correlated with maximum peak velocities obtained by color flow guided continuous-wave Doppler in both in vitro (0.53 to 1.65 m/s, r = 0.99) and in vivo studies (1.50 to 6.01 m/s, r = 0.97). We conclude that the new Quasar technology can accurately measure high blood flow velocities during transesophageal color Doppler echocardiography. This technique has the potential of obviating the need for continuous-wave Doppler.
由于不可避免的混叠问题，传统彩色多普勒无法直接测量高血流速度下的彩色血流信号。一种名为定量无混叠速度算法识别（Quasar）的新技术已被开发出来以克服这一局限性。利用这项技术，我们使用经食管彩色多普勒超声心动图来研究在体外和体内Quasar检测到的速度是否与连续波多普勒获得的速度相关。在体外研究中，使用了康强Sigma 44彩色多普勒血流系统的5.0MHz经食管换能器。随机选择通过彩色多普勒引导的连续波多普勒计算和记录的14种不同的峰值速度。在临床研究中，对18名成年人（13例主动脉瓣狭窄、2例主动脉和2例二尖瓣狭窄、2例肥厚性梗阻性心肌病和1例二尖瓣狭窄）使用相同的换能器进行术中经食管超声心动图检查。在每次连续波多普勒测量之后，激活Quasar，并在彩色血流束最亮的区域放置一个小的Quasar标记，以获得最大平均速度读数。在体外（0.53至1.65米/秒，r = 0.99）和体内研究（1.50至6.01米/秒，r = 0.97）中，Quasar测量的最大平均速度与彩色血流引导的连续波多普勒获得的最大峰值速度密切相关。我们得出结论，新的Quasar技术能够在经食管彩色多普勒超声心动图检查期间准确测量高血流速度。这项技术有可能消除对连续波多普勒的需求。
