Quantitative reconstruction of optical absorption coefficient in backward mode photoacoustic imaging
Journal
SPIE International Symposium on Biomedical Optics
Date Issued
2007-01
Author(s)
C.-K. Liao
Abstract
In this paper, an efficient algorithm for quantitative reconstruction of optical absorption coefficient in backward mode photoacoustic imaging is presented. Compared to forward mode and sideward mode (tomographic) imaging, the setup of backward mode imaging generally has a wider range of clinical applications. However, due to the limited detection angles, quantitative image reconstruction has also been difficult. Previously, we proposed a method for reconstruction of optical energy deposition in backward mode imaging. This method is derived from the photoacoustic wave equations with line focusing, with which the focusing is utilized to reduce the reconstruction problem from three dimensions to one dimension. In this paper, we extend the previous reconstruction method for absorbed optical energy to a two-step procedure for optical absorption coefficient. By adding the second step, backward mode photoacoustic imaging becomes more quantitative as the image is directly related to the inherent properties of an image object. In the proposed method, comparison between the reconstructed and the predicted absorbed energy is then iteratively performed to find the optical absorption distribution. Numerical simulations are conducted to verify efficacy of this method. The errors in reconstructed optical absorption coefficient are generally within 10%. Phantom experiments are also performed. The results are presented with a discussion on effects of object position and geometry.
SDGs
Type
conference paper