Annu Int Conf IEEE Eng Med Biol Soc. 2022 Jul;2022:3043-3046. doi: 10.1109/EMBC48229.2022.9871930.
Ultrasound computed tomography (USCT) is considered to have great potential for breast cancer screening. Compared with the ray based methods, the reconstructed image using full waveform inversion (FWI) methods have higher spatial resolution. However, the results of FWI is difficult to converge to the real value when cycle skipping occurs. In this paper, a cross-correlation full waveform inversion(CC-FWI) is proposed for USCT image reconstruction. In the first stage, the ajoint source is adjusted as the residual of predicted signal and time-shifted measured signal to avoid cycle skipping. In the remaining stage, the FWI with source encoding is employed to accelerate convergence. The simulations are conducted to demonstrate the validity of the proposed algorithm. The root mean squared error (RMSE) of the proposed algorithm is much smaller than that of conventional FWI. The results suggest that CC-FWI is effective in avoiding cycle skipping. Clinical Relevance- Clinical relevance- New imaging modalities of high resolution, safety to examines for early-stage breast cancer imaging are urgently needed for researching and development. Ultra-sound computed tomography (USCT) is supposed to meet the above requirements and it can be potentially deployed in breast scanning.
超声计算机断层扫描（USCT）被认为在乳腺癌筛查方面具有巨大潜力。与射线基方法相比，使用全波形反演（FWI）方法重建的图像具有更高的空间分辨率。然而，当出现循环跳跃时，FWI 的结果很难收敛到真实值。本文提出了一种用于 USCT 图像重建的互相关全波形反演（CC-FWI）。在第一阶段，调整联合源作为预测信号和时间移位测量信号的残差，以避免循环跳跃。在剩余阶段，采用带源编码的 FWI 加速收敛。通过模拟验证了所提出算法的有效性。与传统 FWI 相比，该算法的均方根误差（RMSE）要小得多。结果表明 CC-FWI 可以有效地避免循环跳跃。临床意义- 临床意义- 为了进行早期乳腺癌成像的研究和开发，需要高分辨率、对检查安全的新型成像方式。超声计算机断层扫描（USCT）有望满足上述要求，并有可能在乳房扫描中得到应用。
