L1-regularized Cerenkov luminescence tomography with a SP3 method and CT fusion

Imaging modality of radionuclides has been enriched by an optical approach, Cerenkov luminescence tomography (CLT). Referred to the traditional radionuclide imaging, such as positron emission tomography (PET) or single photon emission computed tomography (SPECT), any incremental improvement of CLT imaging is consistent with the application to information needs. In this contribution, the paper presents an l₁-regularized imaging method for CLT problem. After utilizing the Vavilov-Cerenkov effect via third-order simplified spherical harmonics (SP₃) approximation, we establish the large-scale linear equations in the CLT framework. The derived linear problem is seriously ill-posed, and transformed into an l₁-regularized least squares program. The inverse solution to these equations is the three-dimensional radioisotope recovery data by an interior-point method. In the physical phantom and the in vivo mouse experiment, results demonstrate that the proposed technique produces better imaging quality and improves the reconstruction efficacy, compared with those from diffusion approximation with the Tikhonov regularization.