Contrast distortion correction for photoacoustic image based on compensation for pressure distribution of sound field

MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, 510631, P.R. China

Corresponding author: yangsh@scnu.edu.cn

Received: 11 August 2009
Accepted: 17 November 2009
Published online: 3 February 2010

Abstract

The nonuniform energy density distribution of laser pulses leads to nonuniform pressure distribution of sound field on photoacoustic effect, and photoacoustic image would be distorted at the edge of the absorbed optical energy deposit area. In this paper, a new method for compensating the sound field pressure and correcting the photoacoustic image is reported and testified. Distribution of the photoacoustic pressure was measured with a phase-controlled focus array transducer, and the theoretic function of the photoacoustic pressure was extracted by fitting the distribution curve. The compensation weight factor of the photoacoustic pressure defined as a reciprocal of the theoretic function. Photoacoustic images of a simulation sample and an in vivo mouse brain were reconstructed by correcting with the pressure compensation weight factor. The experimental results showed that this method can uniform the contrast distribution and correct the edge distortion of the PA image, suggesting the potential application in vascular imaging.