A method based on a modified inverse Radon transform is presented to correct photoacoustic and laser-ultrasound section images taken with a cylindrical integrating detector for heterogeneity in the speed of sound. Data for the correction are obtained with a laser ultrasound transmission method, providing two-dimensional maps of the speed of sound distribution. Photoacoustic, laser ultrasound and speed of sound tomography are combined in a single setup using illumination of the sample and several external absorbers with short pulses from a single laser source. The performance of the corrected reconstruction is compared in a simulation and a phantom experiment with a reconstruction using an average, constant sound speed. In this comparison, the reconstruction using the modified inverse Radon transform shows a small but distinguishable improvement.
© 2015 SPIEPDF Article