@inproceedings{0ddbd6b7ca5a495db9bf3d605208bd6b,
title = "Virtual-detector synthetic aperture focusing technique with application in in-vivo photoacoustic microscopy",
abstract = "In this study, we introduce a synthetic aperture focusing technique which employs a virtual detector concept, combined with coherence weighting, to extend the depth of focus for an in-vivo photoacoustic microscopy system. This technique treats the transducer's focal point as a virtual point detector of photoacoustic signals, delays adjacent scan lines relative to the virtual detector, and then sums the delayed signals to achieve focusing in the out-of-focus region. In addition, a coherence factor among the delayed signals for each synthesized imaging point is used as a weighting factor to further improve the focusing quality. Images of an Intralipid phantom containing a carbon fiber show how this technique improves the -6 dB lateral resolution from 49-379 μm to 46-53 μm and increases the SNR by 0-29 dB, depending on the distance from the ultrasonic focal point. In vivo experiments show that this technique also provides a clearer tumor-associated angiogenesis in the mouse's scalp. The extended depth of focus for the photoacoustic microscopy system enables 3D reconstruction of the vascular network for the study of tumor angiogenesis.",
keywords = "Coherence weighting, Depth of focus, Photoacoustic microscopy, Synthetic aperture focusing technique, Virtual detector",
author = "Li, {Meng Lin} and Zhang, {Hao F.} and Konstantin Maslov and George Stoica and Wang, {Lihong V.}",
year = "2006",
doi = "10.1117/12.645115",
language = "English (US)",
isbn = "0819461288",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
booktitle = "Proceedings of SPIE - The International Society for Optical Engineering",
note = "7th Conference on Biomedical Thermoacoustics, Optoacoustics, and Acousto-optics - Photons Plus Ultrasound: Imaging and Sensing 2006 ; Conference date: 22-01-2006 Through 26-01-2006",
}