A method to reconstruct the optical properties in the inhomogeneous medium from the photoacoustic (PA) signal is discussed. The forward modeling of the propagations of the excitation light and of the photoacoustic pressure is carried out with the finite element method. The inverse problem is formulated with a linear equation relating the optical properties and time-domain PA signals. By solving the inverse problem, the distribution of the optical properties in the optically inhomogeneous medium is reconstructed. The measurement noise and the mismatches between the actual measurement conditions and the forward model cause artifacts in the reconstructed image. To reduce the artifacts and to obtain high resolved reconstructed image, we uses the l_p sparsity regularization method which minimizes the l_p norm of the solution of the inverse problem. It is demonstrated by some numerical simulations that the regularization method using the l_p norm obtains a sparse distribution of the changes in the optical properties. The images reconstructed with the l_p sparsity regularization are compared those with truncated singular value decomposition.

Date Published: 4 March 2013
PDF: 6 pages
Proc. SPIE 8581, Photons Plus Ultrasound: Imaging and Sensing 2013, 858135 (4 March 2013); doi: 10.1117/12.2003656

Published in SPIE Proceedings Vol. 8581:
Photons Plus Ultrasound: Imaging and Sensing 2013
Alexander A. Oraevsky; Lihong V. Wang, Editor(s)