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Published November 15, 2013 | Published + Supplemental Material
Journal Article Open

Ultrasonically Encoded Photoacoustic Flowgraphy in Biological Tissue


Blood flow speed is an important functional parameter. Doppler ultrasound flowmetry lacks sufficient sensitivity to slow blood flow (several to tens of millimeters per second) in deep tissue. To address this challenge, we developed ultrasonically encoded photoacoustic flowgraphy combining ultrasonic thermal tagging with photoacoustic imaging. Focused ultrasound generates a confined heat source in acoustically absorptive fluid. Thermal waves propagate with the flow and are directly visualized in pseudo color using photoacoustic computed tomography. The Doppler shift is employed to calculate the flow speed. This method requires only acoustic and optical absorption, and thus is applicable to continuous fluid. A blood flow speed as low as 0.24  mm⋅s^(−1) was successfully measured. Deep blood flow imaging was experimentally demonstrated under 5-mm-thick chicken breast tissue.

Additional Information

© 2013 American Physical Society. Received 8 July 2013; revised manuscript received 11 September 2013; published 12 November 2013. The authors appreciate Professor James Ballard's help with editing the manuscript. This work was sponsored by NIH Grants No. DP1 EB016986 (NIH Director's Pioneer Award), No. R01 EB008085, No. R01 CA134539, No. U54 CA136398, No. R01 CA157277, and No. R01 CA159959. L. Wang and J. Xia contributed equally to this work.

Attached Files

Published - PhysRevLett.111.204301.pdf

Supplemental Material - supplementary_materials.docx

Supplemental Material - supplementary_materials.pdf

Supplemental Material - video1.wmv


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August 19, 2023
October 19, 2023