There has been a growing attention to using acoustic-resolution photoacoustic microscopy (ARPAM) for medical applications in the recent decade. To eliminate the distortion induced by acoustic diffraction in ARPAM, synthetic aperture focusing technique (SAFT) methods that incorporate the virtual detector (VD) concept are used to reconstruct the images. However, most of these algorithms assume homogeneous media and therefore perform poorly in heterogeneous media cases. On this note, we propose an ARPAM reconstruction technique that can be adapted to cases where layered heterogeneous media are present. This method rebuilds a VD-based receiving system by using virtual scan plane theory. It then extrapolates wave fields with the proposed phase-shift factors of different multi-layered media. Afterwards, it adopts a non-uniform fast Fourier transform to reconstruct images. The wave extrapolation eliminates the artifacts induced by refraction, simplifying the computation for layered media. According to the simulations, our proposed method is capable to reconstruct high-quality images for layered heterogeneous media.

中文翻译：

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基于频域的光声成像异质介质虚拟探测器

近十年来，人们越来越关注将声分辨率光声显微镜 (ARPAM) 用于医疗应用。为了消除 ARPAM 中由声学衍射引起的失真，使用结合了虚拟探测器 (VD) 概念的合成孔径聚焦技术 (SAFT) 方法来重建图像。然而，这些算法中的大多数都假设同质媒体，因此在异质媒体情况下表现不佳。在此说明中，我们提出了一种 ARPAM 重建技术，该技术可适用于存在分层异构媒体的情况。该方法利用虚拟扫描平面理论重建了一个基于VD的接收系统。然后用不同多层介质的建议相移因子外推波场。然后，它采用非均匀快速傅立叶变换来重建图像。波外推法消除了折射引起的伪影，简化了分层介质的计算。根据模拟，我们提出的方法能够重建分层异构媒体的高质量图像。