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Published September 5, 2022 | Published + Supplemental Material
Journal Article Open

Cross‐Ray Ultrasound Tomography and Photoacoustic Tomography of Cerebral Hemodynamics in Rodents


Recent advances in functional ultrasound imaging (fUS) and photoacoustic tomography (PAT) offer powerful tools for studying brain function. Complementing each other, fUS and PAT, respectively, measure the cerebral blood flow (CBF) and hemoglobin concentrations, allowing synergistic characterization of cerebral hemodynamics. Here, cross-ray ultrasound tomography (CRUST) and its combination with PAT are presented. CRUST employs a virtual point source from a spherically focused ultrasonic transducer (SFUST) to provide widefield excitation at a 4-kHz pulse repetition frequency. A full-ring-shaped ultrasonic transducer array whose imaging plane is orthogonal to the SFUST's acoustic axis receives scattered ultrasonic waves. Superior to conventional fUS, whose sensitivity to blood flow is angle-dependent and low for perpendicular flow, the crossed transmission and panoramic detection fields of CRUST provide omnidirectional sensitivity to CBF. Using CRUST-PAT, the CBF, oxygen saturation, and hemoglobin concentration changes of the mouse brain during sensory stimulation are measured, with a field of view of ≈7 mm in diameter, spatial resolution of ≈170 µm, and temporal resolution of 200 Hz. The results demonstrate CRUST-PAT as a unique tool for studying cerebral hemodynamics.

Additional Information

© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Version of Record online: 11 July 2022. Manuscript revised: 08 June 2022. Manuscript received: 24 February 2022. The authors thank J. Ballard for editing the manuscript. This work was sponsored by the United States National Institutes of Health (NIH) grant U01 NS099717 (BRAIN Initiative). Authors Contribution. S.N. and Y.Z. contributed equally to this work. L.V.W. and S.N. developed the CRUST method. S.N. developed the system and reconstruction software. S.N. and Y.Z. performed the experiments. L.V.W. proposed the original CRUST concept and supervised the study. S.N. wrote the manuscript with inputs from all authors. Data Availability Statement. The data that support the findings of this study are provided within the paper and its Supporting Information. Conflict of Interest. L.V.W. has a financial interest in Microphotoacoustics, Inc., CalPACT, LLC, and Union Photoacoustic Technologies, Ltd., which, however, did not support this work.

Attached Files

Published - ADVS-9-2201104.pdf

Supplemental Material - advs4300-sup-0001-suppmat.pdf

Supplemental Material - advs4300-sup-0002-videos1.mp4

Supplemental Material - advs4300-sup-0003-videos2.mp4

Supplemental Material - advs4300-sup-0004-videos3.mp4


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August 22, 2023
October 24, 2023