Time efficient scatter correction for time-of-flight PET: the immediate scatter approximation.

Time efficient scatter correction for time-of-flight PET: the immediate scatter approximation.
Phys Med Biol. 2019 Mar 11;:
Authors: Nikulin P, Maus J, Hofheinz F, Lougovski A, van den Hoff J
Abstract
Utilization of Time-Of-Flight (TOF) information allows to improve image quality and convergence rate in iterative PET image reconstruction. In order to obtain quantitatively correct images accurate scatter correction (SC) is required that accounts for the non-uniform distribution of scatter events over the TOF bins. However, existing simplified TOF-SC algorithms frequently exhibit limited accuracy while the currently accepted gold standard - the TOF extension of the single scatter simulation approach (TOF-SSS) - is computationally demanding and can substantially slow down the reconstruction. In this paper we propose and evaluate a new accelerated TOF-SC algorithm in order to improve this situation. The key idea of the algorithm is the use of an immediate scatter approximation (ISA) for scatter time distribution calculation which speeds up estimation of the required TOF scatter by a factor of up to five in comparison to TOF-SSS. The proposed approach was evaluated in dedicated phantom measurements providing challenging high activity contrast conditions as well as in representative clinical patient data sets. Our results show that ISA is a viable alternative to TOF-SSS. The reconstructed images are in excellent quantitative agreement with...

Source: Physics in Medicine and Biology - March 10, 2019 Category: Physics Authors: Nikulin P, Maus J, Hofheinz F, Lougovski A, van den Hoff J Tags: Phys Med Biol Source Type: research