A novel coded excitation scheme to improve spatial and contrast resolution of quantitative ultrasound imaging.
A novel coded excitation scheme to improve spatial and contrast resolution of quantitative ultrasound imaging.
复制标题
一种新颖的编码激励方案，可提高定量超声成像的空间和对比度分辨率。
DOI：
10.1109/tuffc.2009.1294
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Oelze,MichaelL
中科院分区：
文献类型：
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作者：
Sanchez,JoseR;Pocci,Darren;Oelze,MichaelL
基于超声背向散射的定量超声成像技术已成功地应用于疾病的诊断和监测。提出了一种利用分辨率增强压缩(REC)技术提高QUS参数图像对比度和轴向分辨率的方法。分辨率增强压缩是一种编码激励和脉冲压缩技术，可增强超声成像系统的-6⁃分贝带宽。这项研究的目的是将REC和QUS(REC-QUS)结合起来，评估和比较使用REC技术获得的散射体直径估计相对于传统脉冲方法的改进。用中心频率为10 MHz、-6⁃分贝带宽为80%的单元件换能器(f/4)进行了模拟和实验测量。采用REC后，-6⁃分贝带宽提高到155%。用于模拟和实验测量的图像的信噪比均为28分贝。在模拟中，为了监测对比改善的情况，评估了带有圆柱形病变的软件体模。在实验测量中，评估了含有不同散射体直径的玻璃球体的组织模拟体模。通过将归一化后向散射功率谱与-6⁃分贝带宽的理论进行比较，得到了模拟和实验中平均散射体直径的估计值。通过QUS参数图像的估计偏差和标准差、对比度噪声比和直方图分析，量化了REC-QUS相对于传统QUS的改善。总体而言，在模拟过程中，平均散射体直径估计的对比度增加了51%，标准偏差减少了60%，而实验结果的平均散射体直径的标准偏差减少了34%到71%。
Quantitative ultrasound (QUS) imaging techniques based on ultrasonic backscatter have been used successfully to diagnose and monitor disease. A method for improving the contrast and axial resolution of QUS parametric images by using the resolution enhancement compression (REC) technique is proposed. Resolution enhancement compression is a coded excitation and pulse compression technique that enhances the -6⁃dB bandwidth of an ultrasonic imaging system. The objective of this study was to combine REC with QUS (REC-QUS) and evaluate and compare improvements in scatterer diameter estimates obtained using the REC technique to conventional pulsing methods. Simulations and experimental measurements were conducted with a single-element transducer (f/4) having a center frequency of 10 MHz and a -6⁃dB bandwidth of 80%. Using REC, the -6⁃dB bandwidth was enhanced to 155%. Images for both simulation and experimental measurements contained a signal-to-noise ratio of 28 dB. In simulations, to monitor the improvements in contrast a software phantom with a cylindrical lesion was evaluated. In experimental measurements, tissue-mimicking phantoms that contained glass spheres with different scatterer diameters were evaluated. Estimates of average scatterer diameter in the simulations and experiments were obtained by comparing the normalized backscattered power spectra to theory over the -6⁃dB bandwidth for both conventional pulsing and REC. Improvements in REC-QUS over conventional QUS were quantified through estimate bias and standard deviation, contrast-to-noise ratio, and histogram analysis of QUS parametric images. Overall, a 51% increase in contrast and a 60% decrease in the standard deviation of average scatterer diameter estimates were obtained during simulations, while a reduction of 34% to 71% was obtained in the standard deviation of average scatterer diameter for the experimental results.