Multi-angle data acquisition to compensate transducer finite size in photoacoustic tomography

Soheil Hakakzadeh; Moein Mozaffarzadeh; Seyed Masood Mostafavi; Zahra Kavehvash; Praveenbalaji Rajendran; Martin Verweij; Nico de Jong; Manojit Pramanik

doi:10.1016/j.pacs.2022.100373

Multi-angle data acquisition to compensate transducer finite size in photoacoustic tomography

Photoacoustics. 2022 May 21:27:100373. doi: 10.1016/j.pacs.2022.100373. eCollection 2022 Sep.

Authors

Soheil Hakakzadeh¹, Moein Mozaffarzadeh², Seyed Masood Mostafavi¹, Zahra Kavehvash¹, Praveenbalaji Rajendran³, Martin Verweij^{2

4}, Nico de Jong^{2

4}, Manojit Pramanik³

Affiliations

¹ Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran.
² Laboratory of Medical Imaging, Department of Imaging Physics, Delft University of Technology, 2628 CJ Delft, The Netherlands.
³ School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore.
⁴ Department Biomedical Engineering, Thoraxcenter, Erasmus Medical Center, 3015 GD Rotterdam, The Netherlands.

Abstract

In photoacoustic tomography (PAT) systems, the tangential resolution decreases due to the finite size of the transducer as the off-center distance increases. To address this problem, we propose a multi-angle detection approach in which the transducer used for data acquisition rotates around its center (with specific angles) as well as around the scanning center. The angles are calculated based on the central frequency and diameter of the transducer and the radius of the region-of-interest (ROI). Simulations with point-like absorbers (for point-spread-function evaluation) and a vasculature phantom (for quality assessment), and experiments with ten 0.5 mm-diameter pencil leads and a leaf skeleton phantom are used for evaluation of the proposed approach. The results show that a location-independent tangential resolution is achieved with 150 spatial sampling and central rotations with angles of ±8°/±16°. With further developments, the proposed detection strategy can replace the conventional detection (rotating a transducer around ROI) in PAT.

Keywords: Artifacts reduction; Finite transducer size; Photoacoustic tomography; Tangential resolution; Virtual source.