Ultrasound contrast imaging based on a novel algorithm combined pulse inversion with wavelet transform
Ultrasound contrast imaging based on a novel algorithm combined pulse inversion with wavelet transform
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DOI：
10.1109/ultsym.2008.0407
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发表时间：
2008-11
期刊：
影响因子：
--
通讯作者：
Xiaoyan Zhao;M. Wan;Hui Zhong;Liang Shen
中科院分区：
文献类型：
--
作者：
Xiaoyan Zhao;M. Wan;Hui Zhong;Liang Shen
为了增强气泡与周围组织的对比度，提出了一种将脉冲反转技术与小波变换相结合的超声对比度成像方法。利用小波变换分析母子波与接收到的一对反向发射脉冲回波之间的相关性。为了获得更好的相关性，根据修正的Herring方程构造了一种新的母小波--ldquoBubble小波。射频(RF)数据采集自改良的数字化超声诊断系统。在超声流动体模上进行的实验结果表明，与基于脉冲反转的二次谐波成像相比，基于脉冲反转的二次谐波成像的对比度与组织比(CTR)随母波类型、尺度和深度的不同而提高6.4~16.0分贝。利用兔肾脏进行了体内实验，结果表明，与气泡相比，周围组织的信号可以得到很好的抑制。实验结果表明，在相同的实验条件下，采用Bubble小波比Morlet小波和墨西哥帽小波的CTR提高了9.6dB.优化后的气泡小波能更准确地描述气泡的散射回波，可以进一步改进。
In this paper, a novel ultrasound contrast imaging method which combines the pulse-inversion technique with wavelet transform is proposed in order to enhance the contrast between bubbles and surrounding tissues. Wavelet transform is utilized to analyze the correlation between mother wavelet and received echoes from a pair of inverted transmit pulses respectively. In order to obtain better correlation, a new mother wavelet named ldquoBubble waveletrdquo is constructed according to the modified Herring equation. Radio frequency (RF) data were acquired from a modified digital diagnostic ultrasound system. Experiments were performed on an ultrasonic flow phantom and results showed that the contrast-to-tissue ratio (CTR) was improved by 6.4-16.0 dB depending on types of mother wavelet, scales and depths, compared to that obtained using pulse-inversion-based second-harmonic imaging. Experiments in vivo were also conducted out using kidneys of rabbits and results showed that signals of surrounding tissues can be well suppressed compared to that of bubbles. By using Bubble wavelet, the CTR is improved by up to 9.6 dB relative to Morlet wavelet and Mexican Hat wavelet under the same conditions in experiments. Further improvements might be achieved with optimized bubble wavelet which can describe the scattering echoes of the bubbles more accurately.