title: Scatter correction for 3D PET using beam stoppers combined with dual-energy window acquisition: a feasibility study.
abstract: Fully three-dimensional (3D) positron emission tomography (PET) can achieve high sensitivity of coincidence events, but the absence of inter-slice septa inevitably leads to increased scattered events. The scattered events can represent as much as 50% of the total detected events. In this research, we proposed a scatter correction method for 3D PET based on beam stoppers and dual-energy window acquisition. The beam stoppers were placed surrounding the object to attenuate primary beams. The scatter fractions were directly estimated at those blocked lines of response and then the entire scatter fraction distribution was recovered using the dual-energy window ratio as reference. The performance was evaluated by using Monte Carlo simulations of various digital phantoms. For the Utah phantom study, the proposed method accurately estimated the scatter fraction distribution, and improved image contrast and quantification based on four different quality indices as performance measures. For the non-homogeneous Zubal phantom, the simulated results also demonstrated that the proposed method achieved a better restoration of image contrast than the dual-energy window method. We conclude that the proposed scatter correction method could effectively suppress various kinds of scattered events, including multiple scatter and scatter from outside the field of view.
authors.affiliation: Department of Nuclear Science, National Tsing-Hua University, Taiwan. Health Physics Division, Institute of Nuclear Energy Research, Atomic Energy Council, Taiwan.
authors.forename: Jay
authors.initials: J
authors.lastname: Wu
authors.forename: Keh-Shih
authors.initials: KS
authors.lastname: Chuang
authors.forename: Ching-Han
authors.initials: CH
authors.lastname: Hsu
authors.forename: Meei-Ling
authors.initials: ML
authors.lastname: Jan
authors.forename: Ing-Ming
authors.initials: IM
authors.lastname: Hwang
authors.forename: Tzong-Jer
authors.initials: TJ
authors.lastname: Chen
mesh_terms: D003198:Computer Simulation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography; D013902:Radiography, Thoracic