Photoacoustic computed tomography (PACT) is a novel biomedical imaging modality and has experienced fast developments in the past two decades. Spatial resolution is an important criterion to measure the imaging performance of a PACT system. Here we survey state-of-the-art literature on the spatial resolution of PACT and analyze resolution degradation models from signal generation, propagation, reception, to image reconstruction. Particularly, the impacts of laser pulse duration, acoustic attenuation, acoustic heterogeneity, detector bandwidth, detector aperture, detector view angle, discrete sampling, and image reconstruction algorithms are reviewed and discussed. Analytical expressions of point spread functions related to these impacting factors are summarized based on rigorous mathematical formulas. State-of-the-art approaches devoted to enhancing spatial resolution are also reviewed. This work is expected to elucidate the concept of spatial resolution in PACT and inspire novel image quality enhancement techniques.

中文翻译：

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光声计算机断层扫描中的空间分辨率

光声计算机断层扫描 (PACT) 是一种新型的生物医学成像方式，在过去的二十年中经历了快速的发展。空间分辨率是衡量 PACT 系统成像性能的重要标准。在这里，我们调查了有关 PACT 空间分辨率的最新文献，并分析了从信号生成、传播、接收到图像重建的分辨率退化模型。特别是，回顾和讨论了激光脉冲持续时间、声衰减、声学异质性、探测器带宽、探测器孔径、探测器视角、离散采样和图像重建算法的影响。基于严格的数学公式总结了与这些影响因素相关的点扩散函数的解析表达式。还回顾了致力于提高空间分辨率的最新方法。这项工作有望阐明 PACT 中空间分辨率的概念，并激发新的图像质量增强技术。