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Proceedings Paper

Multi-parametric photoacoustic microscopy with 1.2-MHz A-line rate (Conference Presentation)
Author(s): Tianxiong Wang; Rui Cao; Sushanth Govinahallisathyanarayana; John Hossack; Song Hu

Paper Abstract

In the current form of multi-parametric photoacoustic microscopy (PAM), imaging hemoglobin concentration and blood flow speed requires dense sampling. Moreover, large-scale recording beyond the focal zone of ultrasonic transducer requires time-consuming mechanical scan of the optical-acoustic dual foci. Thus, the image acquisition time of multi-parametric PAM has been severely limited by the laser repetition rate and the focal diameter of the transducer. Here, we report an ultrahigh-speed multi-parametric PAM with 1.2-MHz A-line rate for simultaneous real-time imaging of hemoglobin concentration, blood oxygenation, and blood flow in the mouse brain. Capitalizing on the pronounced stimulated Raman scattering in pure silica-core polarization-maintaining single-mode optical fibers, a dual-wavelength (532 and 558 nm) nanosecond laser with 1.2-MHz pulse repetition rate has been developed. Using a weakly focused ultrasonic transducer, we have achieved real-time acquisition of multi-parametric PAM images at a frame rate of 2.2 Hz over the 250-μm-diameter acoustic focal zone. By employing optical-mechanical hybrid scan, 25 dual-wavelength B-scans can be acquired simultaneously within one mechanical-scan trip, leading to a 25-fold improvement of imaging speed. As a result, the imaging frame rate is improved from 0.08 Hz in the conventional multi-parametric PAM to 2.2 Hz. The utility of this new PAM technology has been demonstrated in a mouse model of epilepsy by studying the dynamic neurovascular uncoupling during status epilepticus.

Paper Details

Date Published: 15 March 2018
Proc. SPIE 10494, Photons Plus Ultrasound: Imaging and Sensing 2018, 104941M (15 March 2018);
Show Author Affiliations
Tianxiong Wang, Univ. of Virginia (United States)
Rui Cao, Univ. of Virginia (United States)
Sushanth Govinahallisathyanarayana, Univ. of Virginia (United States)
John Hossack, Univ. of Virginia (United States)
Song Hu, Univ. of Virginia (United States)

Published in SPIE Proceedings Vol. 10494:
Photons Plus Ultrasound: Imaging and Sensing 2018
Alexander A. Oraevsky; Lihong V. Wang, Editor(s)

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