Experimental validation of tangential resolution improvement in photoacoustic tomography using modified delay-and-sum reconstruction algorithm
Kalva, Sandeep Kumar
Date of Issue2016
School of Chemical and Biomedical Engineering
For a circular scanning geometry in photoacoustic tomography, the axial/radial resolution is spatially invariant and is not affected by the ultrasound transducer (UST, detector) aperture. However, the tangential resolution is dependent on the detector aperture size and it varies spatially. Many techniques were proposed to improve the tangential resolution, such as attaching a concave lens in front of the nonfocused transducer or using a virtual point detector. Both of these methods have difficulties. Therefore, a modified delay-and-sum reconstruction algorithm has been proposed which can be used together with a standard ultrasound detector (nonfocused) to improve the tangential resolution. In this work, we validate the modified delay-and-sum algorithm experimentally for both flat and cylindrically focused USTs. More than threefold improvement in tangential resolution is observed. It is also shown that the object shape is recovered with this modified algorithm, which is very helpful for diagnosis and treatment purposes.
Journal of Biomedical Optics
© 2016 Society of Photo-optical Instrumentation Engineers (SPIE). This paper was published in Journal of Biomedical Optics and is made available as an electronic reprint (preprint) with permission of SPIE. The published version is available at: [http://dx.doi.org/10.1117/1.JBO.21.8.086011]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.