High frequency nonlinear B-scan imaging of microbubble contrast agents
High frequency nonlinear B-scan imaging of microbubble contrast agents
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DOI：
10.1109/tuffc.2005.1397351
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发表时间：
2005-01-01
影响因子：
3.6
通讯作者：
Foster, FS
中科院分区：
文献类型：
--
作者：
Goertz, DE;Cherin, E;Foster, FS
先前表明，使用14-32 MHz范围内的发射频率从微泡造影剂产生非线性散射是可能的，这表明执行高频非线性微泡成像的可能性。在这项研究中，我们描述了非线性微泡B扫描成像仪器的发展能够在10和50 MHz之间的发射中心频率。该系统使用20和30 MHz的发射频率进行验证实验。代理表征实验表明在本研究中使用的条件下的非线性散射的存在。使用无壁血管体模，使用20和30 MHz发射频率的次谐波、超谐波和二次谐波频率区域之一中的能量进行非线性B扫描成像。次谐波和超谐波成像模式均实现了将组织信号抑制到本底噪声以下，同时分别实现了高达26 dB和17 dB的对比噪声比。二次谐波成像的性能受到非线性传播的影响，并且与基模成像相比没有提供显著的对比度改善。在体内实验中，使用20 MHz的发射脉冲的次谐波显示成功的检测微血管是在兔耳和小鼠心脏。本研究的结果证明了非线性微泡成像在高频下的可行性。
It previously was shown that it is possible to produce nonlinear scattering from microbubble contrast agents using transmit frequencies in the 14-32 MHz range, suggesting the possibility of performing high-frequency, nonlinear microbubble imaging. In this study, we describe the development of nonlinear microbubble B-scan imaging instrumentation capable of operating at transmit center frequencies between 10 and 50 MHz. The system underwent validation experiments using transmit frequencies of 20 and 30 MHz. Agent characterization experiments demonstrate the presence of nonlinear scattering for the conditions used in this study. Using wall-less vessel phantoms, nonlinear B-scan imaging is performed using energy in one of the subharmonic, ultraharmonic, and second harmonic frequency regions for transmit frequencies of 20 and 30 MHz. Both subharmonic and ultraharmonic imaging modes achieved suppression of tissue signals to below the noise floor while achieving contrast to noise ratios of up to 26 and 17 dB, respectively. The performance of second harmonic imaging was compromised by nonlinear propagation and offered no significant contrast improvement over fundamental mode imaging. In vivo experiments using the subharmonic of a 20 MHz transmit pulse show the successful detection of microvessels Is in the rabbit ear and in the mouse heart. The results of this study demonstrate the feasibility of nonlinear microbubble imaging at high frequencies.