The fidelity and quality of reconstructed images in optoacoustic mesoscopy (OPAM) can be significantly improved by considering the spatial impulse response (SIR) of the employed focused transducer into reconstruction. However, the traditional method fully taking the SIR into account can hardly meet the data-intensive requirements of high resolution OPAM because of excessive memory and time consumption. Herein, a modified back-projection method using a space-variant filter for full-frequency correction of the SIR is presented, and applied to the OPAM system with a sphere-focused transducer. The proposed method can readily manage the large datasets of the OPAM and effectively reduce the extra time consumption. The performance of the proposed method is showcased by simulations and experiments of phantoms and biological tissue. The results demonstrate that the modified back-projection method exhibits better image fidelity, resolution and contrast compared to the common and weighted back-projection methods that are not or not fully accounting for the SIR.

通过考虑所采用的聚焦换能器在重建过程中的空间冲激响应（SIR），可以显着提高光声介观（OPAM）中重建图像的保真度和质量。然而，由于过多的存储和时间消耗，充分考虑了SIR的传统方法几乎不能满足高分辨率OPAM的数据密集型要求。在此，提出了一种使用空间变量滤波器对SIR进行全频校正的改进的反投影方法，并将其应用于具有球形聚焦换能器的OPAM系统。所提出的方法可以容易地管理OPAM的大型数据集，并有效地减少了额外的时间消耗。通过对模型和生物组织的仿真和实验展示了所提出方法的性能。