Enhanced spatial resolution in fluorescence molecular tomography using restarted L1-regularized nonlinear conjugate gradient algorithm

Junwei Shi; Fei Liu; Guanglei Zhang; Jianwen Luo; Jing Bai

doi:10.1117/1.JBO.19.4.046018

28 April 2014 Enhanced spatial resolution in fluorescence molecular tomography using restarted L1-regularized nonlinear conjugate gradient algorithm

Junwei Shi, Fei Liu, Guanglei Zhang, Jianwen Luo, Jing Bai

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Journal of Biomedical Optics, Vol. 19, Issue 4, 046018 (April 2014). https://doi.org/10.1117/1.JBO.19.4.046018

Abstract

Owing to the high degree of scattering of light through tissues, the ill-posedness of fluorescence molecular tomography (FMT) inverse problem causes relatively low spatial resolution in the reconstruction results. Unlike L2 regularization, L1 regularization can preserve the details and reduce the noise effectively. Reconstruction is obtained through a restarted L1 regularization-based nonlinear conjugate gradient (re-L1-NCG) algorithm, which has been proven to be able to increase the computational speed with low memory consumption. The algorithm consists of inner and outer iterations. In the inner iteration, L1-NCG is used to obtain the L1-regularized results. In the outer iteration, the restarted strategy is used to increase the convergence speed of L1-NCG. To demonstrate the performance of re-L1-NCG in terms of spatial resolution, simulation and physical phantom studies with fluorescent targets located with different edge-to-edge distances were carried out. The reconstruction results show that the re-L1-NCG algorithm has the ability to resolve targets with an edge-to-edge distance of 0.1 cm at a depth of 1.5 cm, which is a significant improvement for FMT.

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Junwei Shi, Fei Liu, Guanglei Zhang, Jianwen Luo, and Jing Bai "Enhanced spatial resolution in fluorescence molecular tomography using restarted L1-regularized nonlinear conjugate gradient algorithm," Journal of Biomedical Optics 19(4), 046018 (28 April 2014). https://doi.org/10.1117/1.JBO.19.4.046018

Published: 28 April 2014

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