Acoustic properties of biological tissues usually vary inhomogeneously in space. Tissues with different chemical composition often have different acoustic properties. The assumption of acoustic homogeneity may lead to blurred details, misalignment of targets and artifacts in the reconstructed photoacoustic tomography (PAT) images. This paper summarizes the main solutions to PAT imaging of acoustically heterogeneous tissues, including the variable sound speed and acoustic attenuation. The advantages and limits of the methods are discussed and the possible future development is prospected.
生物组织声学特性的空间变化通常是未知的，不同成分的组织往往具有不同的声学特性。对于光声层析成像（PAT），恒定声速和声学特性均匀分布的假设会导致重建图像的细节模糊、目标错位及图像伪影等问题。本文对生物 PAT 图像重建中组织声学特性不均匀性问题（主要是声速不均匀和声衰减）的主要解决方法进行总结和归纳，讨论各方法的优势和不足，并展望未来可能的发展方向。.
Keywords: acoustic attenuation; acoustic heterogeneity; image reconstruction; photoacoustic tomography.