Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
IBM Research-China, ZPark, Beijing 100085, China.
Exp Biol Med (Maywood). 2020 Apr;245(7):597-605. doi: 10.1177/1535370220914285. Epub 2020 Mar 25.
With balanced spatial resolution, penetration depth, and imaging speed, photoacoustic computed tomography (PACT) is promising for clinical translation such as in breast cancer screening, functional brain imaging, and surgical guidance. Typically using a linear ultrasound (US) transducer array, PACT has great flexibility for hand-held applications. However, the linear US transducer array has a limited detection angle range and frequency bandwidth, resulting in limited-view and limited-bandwidth artifacts in the reconstructed PACT images. These artifacts significantly reduce the imaging quality. To address these issues, existing solutions often have to pay the price of system complexity, cost, and/or imaging speed. Here, we propose a deep-learning-based method that explores the Wasserstein generative adversarial network with gradient penalty (WGAN-GP) to reduce the limited-view and limited-bandwidth artifacts in PACT. Compared with existing reconstruction and convolutional neural network approach, our model has shown improvement in imaging quality and resolution. Our results on simulation, phantom, and data have collectively demonstrated the feasibility of applying WGAN-GP to improve PACT’s image quality without any modification to the current imaging set-up.
This study has the following main impacts. It offers a promising solution for removing limited-view and limited-bandwidth artifact in PACT using a linear-array transducer and conventional image reconstruction, which have long hindered its clinical translation. Our solution shows unprecedented artifact removal ability for image, which may enable important applications such as imaging tumor angiogenesis and hypoxia. The study reports, for the first time, the use of an advanced deep-learning model based on stabilized generative adversarial network. Our results have demonstrated its superiority over other state-of-the-art deep-learning methods.
光声计算层析成像(PACT)具有平衡的空间分辨率、穿透深度和成像速度,有望应用于临床转化,如乳腺癌筛查、功能脑成像和手术指导。通常使用线性超声(US)换能器阵列,PACT 在手持应用方面具有很大的灵活性。然而,线性 US 换能器阵列的检测角度范围和频率带宽有限,导致重建的 PACT 图像中存在有限视角和有限带宽伪影。这些伪影显著降低了成像质量。为了解决这些问题,现有的解决方案往往不得不付出系统复杂性、成本和/或成像速度的代价。在这里,我们提出了一种基于深度学习的方法,探索了带有梯度惩罚的 Wasserstein 生成对抗网络(WGAN-GP),以减少 PACT 中的有限视角和有限带宽伪影。与现有的重建和卷积神经网络方法相比,我们的模型在成像质量和分辨率方面都有了提高。我们在模拟、体模和数据上的结果共同证明了在不改变当前成像设置的情况下,应用 WGAN-GP 来提高 PACT 图像质量的可行性。
本研究具有以下主要影响。它为使用线性阵列换能器和传统图像重建去除 PACT 中的有限视角和有限带宽伪影提供了一个有前途的解决方案,这长期以来一直阻碍着它的临床转化。我们的解决方案为图像提供了前所未有的伪影去除能力,这可能使肿瘤血管生成和缺氧成像等重要应用成为可能。本研究首次报告了使用基于稳定生成对抗网络的先进深度学习模型。我们的结果表明,它优于其他最先进的深度学习方法。