Modified delay-and-sum reconstruction algorithm to improve tangential resolution in photoacoustic tomography
Kalva, Sandeep Kumar
Date of Issue2017
Proceedings of SPIE - Photons Plus Ultrasound: Imaging and Sensing 2017
School of Chemical and Biomedical Engineering
In photoacoustic/optoacoustic tomography (PAT/OAT) for a circular scanning geometry, the axial/radial resolution is not variant spatially and also do not depend on the ultrasound transducer (UST) aperture. But the tangential resolution is affected by the size of the detector aperture and is spatially variant. To counter this problem many techniques such as attaching a negative lens to the transducer surface, or using virtual detectors were proposed. However these techniques have difficulties. Therefore, a modified delay-and-sum reconstruction algorithm was proposed which can be used with the normal UST to improve the tangential resolution. In this work, we demonstrate the improvement of tangential resolution using the modified delay-and-sum reconstruction algorithm with experimental data. We have obtained more than twofold improvement of resolution in the tangential direction using non-focused and cylindrically focused USTs in a circular scanning geometry. We also observe that shape of the target object can also be preserved which is helpful for diagnosis and treatment purposes.
© 2017 Society of Photo-optical Instrumentation Engineers (SPIE). This paper was published in Proceedings of SPIE - Photons Plus Ultrasound: Imaging and Sensing 2017 and is made available as an electronic reprint (preprint) with permission of Society of Photo-optical Instrumentation Engineers (SPIE). The published version is available at: [http://dx.doi.org/10.1117/12.2250487]. 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.