title: Validation of a simplified scatter correction method for 3D brain PET with15O.
abstract: OBJECTIVE
  Positron emission tomography (PET) enables quantitative measurements of various biological functions. Accuracy in data acquisition and processing schemes is a prerequisite for this. The correction of scatter is especially important when a 3D PET scanner is used. The aim of this study was to validate the use of a simplified calculation-based scatter correction method for15O studies in the brain.
  
  
  METHODS
  We applied two scatter correction methods to the same15O PET data acquired from patients with cerebrovascular disease (n = 10): a hybrid dual-energy-window scatter correction (reference method), and a deconvolution scatter correction (simplified method). The PET study included three sequential scans for15O-CO,15O-O2, and15O-H2O, from which the following quantitative parameters were calculated, cerebral blood flow, cerebral blood volume, cerebral metabolic rate of oxygen, and oxygen extraction fraction.
  
  
  RESULTS
  Both scatter correction methods provided similar reconstruction images with almost identical image noise, although there were slightly greater differences in white-matter regions compared with gray matter regions. These differences were also greater for15O-CO than for15O-H2O and15O-O2. Region of interest analysis of the quantitative parameters demonstrated that the differences were less than 10 % (except for cerebral blood volume in white-matter regions), and the agreement between the methods was excellent, with intraclass correlation coefficients above 0.95 for all the parameters.
  
  
  CONCLUSIONS
  The deconvolution scatter correction despite its simplified implementation provided similar results to the hybrid dual-energy-window scatter correction. We consider it suitable for application in a clinical15O brain study using a 3D PET scanner.
authors.affiliation: Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, 6-10 Senshu-Kubota Machi, Akita, 010-0874, Japan. iba@akita-noken.jp.
authors.forename: Masanobu
authors.identifier: http://orcid.org/0000-0002-4280-6470
authors.initials: M
authors.lastname: Ibaraki
authors.affiliation: Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, 6-10 Senshu-Kubota Machi, Akita, 010-0874, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Matsubara
authors.affiliation: Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, 6-10 Senshu-Kubota Machi, Akita, 010-0874, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Sato
authors.affiliation: Medical System Division, Shimadzu Corporation, Kyoto, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Mizuta
authors.affiliation: Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, 6-10 Senshu-Kubota Machi, Akita, 010-0874, Japan.
authors.forename: Toshibumi
authors.initials: T
authors.lastname: Kinoshita
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D010104:Oxygen Radioisotopes; D049268:Positron-Emission Tomography; D012542:Scattering, Radiation
chemical_list: D010104:Oxygen Radioisotopes
keywords: 15O; Brain; PET; Scatter correction