Based on the energy conversion of light into sound, photoacoustic computed tomography (PACT) is an emerging biomedical imaging modality and has unique applications in a range of biomedical fields. In PACT, image formation relies on a process called acoustic inversion from received photoacoustic signals. While most PACT systems perform this inversion with a basic assumption that biological tissues are acoustically homogeneous, the community gradually realizes that the intrinsic acoustic heterogeneity of tissues could pose distortions and artifacts to finally formed images. This paper surveys the most recent research progress on acoustic heterogeneity correction in PACT. Four major strategies are reviewed in detail, including half-time or partial-time reconstruction, autofocus reconstruction by optimizing sound speed maps, joint reconstruction of optical absorption and sound speed maps, and ultrasound computed tomography (USCT) enhanced reconstruction. The correction of acoustic heterogeneity helps improve the imaging performance of PACT.

中文翻译：

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对抗光声计算机断层扫描中的声学异质性：综述

基于将光能量转换为声音的光声计算机断层扫描 (PACT) 是一种新兴的生物医学成像模式，在一系列生物医学领域具有独特的应用。在 PACT 中，图像形成依赖于从接收到的光声信号中称为声学反转的过程。虽然大多数 PACT 系统以生物组织在声学上是同质的基本假设来执行这种反演，但社区逐渐意识到组织的内在声学异质性可能会对最终形成的图像造成失真和伪影。本文综述了 PACT 中声学异质性校正的最新研究进展。详细回顾了四大策略，包括半时间或部分时间重建，通过优化声速图的自动对焦重建，光学吸收和声速图的联合重建，以及超声计算机断层扫描 (USCT) 增强重建。声学异质性的校正有助于提高 PACT 的成像性能。