Frequency domain ultrasound waveform tomography: breast imaging using a ring transducer.
Frequency domain ultrasound waveform tomography: breast imaging using a ring transducer.
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DOI：
10.1088/0031-9155/60/14/5381
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发表时间：
2015-07-21
影响因子：
3.5
通讯作者：
Duric N
中科院分区：
文献类型：
--
作者：
Sandhu GY;Li C;Roy O;Schmidt S;Duric N
将频域声波方程应用到从超声断层扫描获取的数据上可以产生与最高重建频率的波长数量级的高分辨率声速图像。使用 0.4–1 MHz 的信号带宽和 1500 m/s 的平均声速，分辨率约为 1.5 mm。这些图像提供的定量声速值和形态有可能为乳腺疾病的诊断和分类提供信息。在这项研究中，我们介绍了波形断层扫描的形式、实际应用和体内结果，该波形断层扫描应用于由两种不同的使用环形换能器的超声断层扫描仪收集的乳腺数据。形式包括对使用有限差分算子的波动方程频域建模的回顾以及对迭代重建方案的梯度下降法的回顾。结果表明，波形断层扫描的实际应用需要准确的启动模型、仔细的数据处理以及逐步将较高频率信息纳入声速重建的方法。按照这些步骤产生了乳房的高分辨率定量声速图像。相对于常用的射线断层扫描重建方法，这些图像显示出显着的改进。通过从两个不同的超声断层扫描设备获得相似的结果证明了该方法的稳健性。我们还将我们的方法与 MRI 进行比较，以证明一致的结果。本工作中使用的临床数据来自符合 HIPAA 的临床研究 (IRB 040912M1F)。
Application of the frequency domain acoustic wave equation on data acquired from ultrasound tomography scans is shown to yield high resolution sound speed images on the order of the wavelength of the highest reconstructed frequency. Using a signal bandwidth of 0.4–1 MHz and an average sound speed of 1500 m/s, the resolution is approximately 1.5 mm. The quantitative sound speed values and morphology provided by these images have the potential to inform diagnosis and classification of breast disease. In this study, we present the formalism, practical application, and in vivo results of waveform tomography applied to breast data gathered by two different ultrasound tomography scanners that utilize ring transducers. The formalism includes a review of frequency domain modeling of the wave equation using finite difference operators as well as a review of the gradient descent method for the iterative reconstruction scheme. It is shown that the practical application of waveform tomography requires an accurate starting model, careful data processing, and a method to gradually incorporate higher frequency information into the sound speed reconstruction. Following these steps resulted in high resolution quantitative sound speed images of the breast. These images show marked improvement relative to commonly used ray tomography reconstruction methods. The robustness of the method is demonstrated by obtaining similar results from two different ultrasound tomography devices. We also compare our method to MRI to demonstrate concordant findings. The clinical data used in this work was obtained from a HIPAA compliant clinical study (IRB 040912M1F).