Xu Minghua, Wang Lihong V
Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A&M University, 3120 TAMU, College Station, TX 77843-3120, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 May;67(5 Pt 2):056605. doi: 10.1103/PhysRevE.67.056605. Epub 2003 May 9.
An analytic explanation of the spatial resolution in thermoacoustic or photoacoustic reconstruction is presented. Three types of specific recording geometries, including spherical, planar, and cylindrical surface, as well as other general cases, are investigated. Analytic expressions of the point-spread functions (PSF's), as a function of the bandwidth of the measurement system and the finite size of the detector aperture, are derived based on rigorous reconstruction formulas. The analyses clearly reveal that the dependence of the PSF's on the bandwidth of all recording geometries shares the same space-invariant expression while the dependence on the aperture size of the detector differs. The bandwidth affects both axial and lateral resolutions; in contrast, the detector aperture blurs the lateral resolution greatly but the axial resolution only slightly.
本文给出了热声或光声重建中空间分辨率的解析解释。研究了三种特定的记录几何结构，包括球面、平面和圆柱面，以及其他一般情况。基于严格的重建公式，推导了作为测量系统带宽和探测器孔径有限尺寸函数的点扩散函数（PSF）的解析表达式。分析清楚地表明，PSF对所有记录几何结构带宽的依赖具有相同的空间不变表达式，而对探测器孔径大小的依赖则不同。带宽影响轴向分辨率和横向分辨率；相比之下，探测器孔径极大地模糊了横向分辨率，但对轴向分辨率的影响较小。
