Generalized spatial coherence reconstruction for photoacoustic computed tomography.
Generalized spatial coherence reconstruction for photoacoustic computed tomography.
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DOI：
10.1117/1.jbo.26.4.046002
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发表时间：
2021-04
影响因子：
3.5
通讯作者：
Gao L
中科院分区：
文献类型：
--
作者：
Tordera Mora J;Feng X;Nyayapathi N;Xia J;Gao L
意义：相干性是波和场的基本性质，在光声图像重建中起着关键作用。先前，诸如短滞后空间相干性（SLSC）和滤波延迟、相乘和求和（FDMAS）的技术已经利用空间相干性来改善相对于延迟和求和（DAS）的重构分辨率和对比度。SLSC直接使用空间相干性作为成像对比度，而FDMAS隐含地使用空间相干性。尽管对噪声更鲁棒，但这两种技术都有自己的缺点：SLSC不保留相对信号幅度，FDMAS显示出降低的对比度噪声比。目的：为了克服这些局限性，我们的目标是开发一种波束形成算法广义空间相干（GSC）-将SLSC和FDMAS统一到一个单一的方程，并优于两个波束形成器。方法：我们通过仿真和实验证明了GSC在光声计算机断层扫描（PACT）中的应用，并将其与以前的波束形成器DAS，FDMAS和SLSC进行了比较。结果：GSC优于以前的国家的最先进的相干波束形成器在仿真和实验中的成像指标。结论：GSC是一种新的PACT重建算法，它结合了FDMAS和SLSC的优点，扩展了PACT的应用范围。
Significance: Coherence, a fundamental property of waves and fields, plays a key role in photoacoustic image reconstruction. Previously, techniques such as short-lag spatial coherence (SLSC) and filtered delay, multiply, and sum (FDMAS) have utilized spatial coherence to improve the reconstructed resolution and contrast with respect to delay-and-sum (DAS). While SLSC uses spatial coherence directly as the imaging contrast, FDMAS employs spatial coherence implicitly. Despite being more robust against noise, both techniques have their own drawbacks: SLSC does not preserve a relative signal magnitude, and FDMAS shows a reduced contrast-to-noise ratio. Aim: To overcome these limitations, our aim is to develop a beamforming algorithm—generalized spatial coherence (GSC)—that unifies SLSC and FDMAS into a single equation and outperforms both beamformers. Approach: We demonstrated the application of GSC in photoacoustic computed tomography (PACT) through simulation and experiments and compared it to previous beamformers: DAS, FDMAS, and SLSC. Results: GSC outperforms the imaging metrics of previous state-of-the-art coherence-based beamformers in both simulation and experiments. Conclusions: GSC is an innovative reconstruction algorithm for PACT, which combines the strengths of FDMAS and SLSC expanding PACT’s applications.