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Published May 2021 | Accepted Version + Supplemental Material
Journal Article Open

Snapshot photoacoustic topography through an ergodic relay of optical absorption in vivo


Photoacoustic tomography (PAT) has demonstrated versatile biomedical applications, ranging from tracking single cells to monitoring whole-body dynamics of small animals and diagnosing human breast cancer. Currently, PAT has two major implementations: photoacoustic computed tomography (PACT) and photoacoustic microscopy (PAM). PACT uses a multi-element ultrasonic array for parallel detection, which is relatively complex and expensive. In contrast, PAM requires point-by-point scanning with a single-element detector, which has a limited imaging throughput. The trade-off between the system cost and throughput demands a new imaging method. To this end, we have developed photoacoustic topography through an ergodic relay (PATER). PATER can capture a wide-field image with only a single-element ultrasonic detector upon a single laser shot. This protocol describes the detailed procedures for PATER system construction, including component selection, equipment setup and system alignment. A step-by-step guide for in vivo imaging of a mouse brain is provided as an example application. Data acquisition, image reconstruction and troubleshooting procedures are also elaborated. It takes ~130 min to carry out this protocol, including ~60 min for both calibration and snapshot wide-field data acquisition using a laser with a 2-kHz pulse repetition rate. PATER offers low-cost snapshot wide-field imaging of fast dynamics, such as visualizing blood pulse wave propagation and tracking melanoma tumor cell circulation in mice in vivo. We envision that PATER will have wide biomedical applications and anticipate that the compact size of the setup will allow it to be further developed as a wearable device to monitor human vital signs.

Additional Information

© 2021 Nature Publishing Group. Received 17 July 2020; Accepted 16 December 2020; Published 12 April 2021. This work was supported in part by National Institutes of Health grants R01 CA186567 (NIH Director's Transformative Research Award), R01 NS102213, U01 NS099717 (BRAIN Initiative), R35 CA220436 (Outstanding Investigator Award) and R01 EB028277. Data availability: All data generated or analyzed within this study are included in the article and ref. 10. The raw data for Figs. 2 and 3 can be downloaded via the following links: Fig. 2, https://figshare.com/articles/dataset/Data_for_Fig_2/12950798; Fig. 3, https://figshare.com/articles/dataset/Data_for_Fig_3/12591953. All other raw data are available from the corresponding author upon request. Code availability: The reconstruction algorithm and data processing methods are described in detail in this protocol. The reconstruction algorithm is provided with this protocol as Supplementary Software 1. These authors contributed equally: Lei Li, Yang Li. Author Contributions: L.L. and Y.L. developed the imaging system. L.L., Y.L. and Y.Z. designed and performed the experiments. L.V.W. supervised the study. All authors contributed to writing the manuscript. Competing interests: L.V.W. has financial interests in Microphotoacoustics, Inc.; CalPACT, LLC; and Union Photoacoustic Technologies, Ltd., which did not support this work. Peer review information: Nature Protocols thanks Miya Ishihara, Guenther Paltauf and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Attached Files

Accepted Version - nihms-1708131.pdf

Supplemental Material - 41596_2020_487_MOESM1_ESM.pdf

Supplemental Material - 41596_2020_487_MOESM2_ESM.zip

Supplemental Material - 41596_2020_487_MOESM3_ESM.zip


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August 22, 2023
October 23, 2023