A Monte Carlo scattering correction method for Lu-176 induced background radiation

Maximum likelihood activity and attenuation estimation, maximum likelihood activity and attenuation correction factors estimation algorithm were developed to reconstruct the activity image in CT-less PET scans. Additional attenuation information can be obtained through the analysis of background radiation from Lu-176 in LYSO/LSO crystals. In this study, we developed a fast GPU-based Monte Carlo scattering correction method for background radiation to achieve more accurate attenuation factors. Background data was acquired on the uMI Panorama GS platform to evaluate the effectiveness of the scattering correction method. There have been two scans performed, one with an empty field of view and the other with a NEMA IQ phantom inside. Reconstructed results of the test phantom's linear attenuation coefficient (mu, denoted as μ) image by the MLTR algorithm showed that the scattering correction method can effectively improve the accuracy of attenuation information introduced by background radiation, where the bias of water’s mu value was reduced from 10%-20% to less than 5%.