Tripling the detection view of high-frequency linear-array-based photoacoustic computed tomography by using two planar acoustic reflectors

Quant Imaging Med Surg. 2015 Feb;5(1):57-62. doi: 10.3978/j.issn.2223-4292.2014.11.09.

Abstract

Background: Linear-array-based photoacoustic computed tomography (PACT) suffers from a limited view. Circular scanning does increase the detection view angle but is time-consuming. Therefore, it is desirable to increase the detection view angle of linear-array-based PACT without sacrificing imaging speed.

Methods: Two planar acoustic reflectors placed at 120 degrees to each other were added to a linear-array-based PACT system. Each reflector redirects originally undetectable photoacoustic waves back to the transducer array elements, and together they triple the original detection view angle of the PACT system.

Results: Adding two reflectors increased the detection view angle from 80 to 240 degrees. As a comparison, a single-reflector PACT has a detection view angle of only 160 degrees. A leaf skeleton phantom with a rich vascular network was imaged with the double-reflector PACT, and most of its features were recovered.

Conclusions: The two acoustic reflectors triple the detection view angle of a linear-array-based PACT without compromising the original imaging speed. This nearly full-view detection capability produces higher-quality images than single-reflector PACT or conventional PACT without reflectors.

Keywords: Photoacoustic computed tomography (PACT); acoustic reflector; limited view; linear transducer array; view angle.