Photoacoustic speckle tracking for motion estimation and flow analysis

• Type of Material: Article
• Authors: Hein de de Hoop, Georgia Institute of Technology; Heechul Yoon, Georgia Institute of Technology; Kelsey Kubelick, Georgia Institute of Technology; Stanislav Emelianov, Emory University
• Language: English
• Date: 2018-09-01
• Publisher: Society of Photo-optical Instrumentation Engineers (SPIE)
• Publication Version: Final Published Version
• Copyright Statement: © 2018 Society of Photo-Optical Instrumentation Engineers (SPIE).
• Final Published Version (URL): http://dx.doi.org/10.1117/1.JBO.23.9.096001
• Title of Journal or Parent Work: Journal of Biomedical Optics
• ISSN: 1083-3668
• Volume: 23
• Issue: 9
• Start Page: 1
• End Page: 9
• Grant/Funding Information: This work was supported in part by the National Institute of Health under Grant Nos. CA158598 and NS090336.
• Keywords: motion analysis; shunt malfunction; Biochemistry & Molecular Biology; MICROPARTICLES; flow imaging; ultrasound imaging; Biochemical Research Methods; Radiology, Nuclear Medicine & Medical Imaging; Physical Sciences; photoacoustic imaging; Science & Technology; Life Sciences & Biomedicine; Optics; speckle tracking
• Research Categories: Physics, Optics; Physics, Acoustics

Abstract

This study explores photoacoustic (PA) speckle tracking to characterize flow as an alternative to ultrasound (US) speckle tracking or current PA flow imaging methods. In cases where tracking of submicrometer particles is required, the US signal-to-noise ratio and contrast might be low due to limited reflectivity of subwavelength size targets at low concentrations. However, it may be possible to perform more accurate velocimetry using PAs due to different contrast mechanisms utilized in PA imaging. Here, we introduce a PA-based speckle tracking method that overcomes the directional dependence of Doppler imaging and the limited field of view of current correlation-based methods used in PA flow imaging. The feasibility of this method is demonstrated in a potential application-minimally invasive diagnosis of ventricular shunt malfunction, where the velocity of optically absorbing particles was estimated in a shunt catheter using block matching of PA and US signals. Overall, our study demonstrates the potential of the PA-based motion tracking method under various flow rates where US imaging cannot be effectively used for specking tracking because of its low contrast and low signal-to-noise ratio.