2D study of a joint reconstruction algorithm for limited angle PET geometries

Abstract

[EN] Recently, a wide interest on organ-dedicated PET systems has been shown. Some of those systems present geometries that produce an incomplete sampling of the tomographic data due to limited angular coverage and/or truncation, which lead to artifacts on the reconstructed image. Moreover, they are often designed as standalone systems, which implies the absence of anatomical information to estimate the attenuation factors. In this work, we propose a joint reconstruction algorithm for estimating the activity and the attenuation factors on a limited angle PET system with time-of-flight capabilities. This algorithm is based on MLACF and uses literature linear attenuation coefficients in a known tissue-class region to obtain an absolute quantification. We evaluate the algorithm through simple 2D simulations for different TOF resolutions and angular coverage. The results show that with good TOF resolution quantitative PET imaging can be achieved even with aggressive angular limitation.