title: Investigation of Image Reconstruction Parameters of the Mediso nanoScan PC Small-Animal PET/CT Scanner for Two Different Positron Emitters Under NEMA NU 4-2008 Standards.
abstract: The Tera-Tomo 3D image reconstruction algorithm (a version of OSEM), provided with the Mediso nanoScan® PC (PET8/2) small-animal positron emission tomograph (PET)/x-ray computed tomography (CT) scanner, has various parameter options such as total level of regularization, subsets, and iterations. Also, the acquisition time in PET plays an important role. This study aims to assess the performance of this new small-animal PET/CT scanner for different acquisition times and reconstruction parameters, for 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) and Ga-68, under the NEMA NU 4-2008 standards.
  
  
  
  Various image quality metrics were calculated for different realizations of [18F]FDG and Ga-68 filled image quality (IQ) phantoms.
  
  
  
  [18F]FDG imaging produced improved images over Ga-68. The best compromise for the optimization of all image quality factors is achieved for at least 30 min acquisition and image reconstruction with 52 iteration updates combined with a high regularization level.
  
  
  
  A high regularization level at 52 iteration updates and 30 min acquisition time were found to optimize most of the figures of merit investigated.
authors.affiliation: PET/CT Department and Small Animal PET/CT Unit, Centre for Clinical Research, Experimental Surgery & Translational Research, Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens, Greece. agaitanis@bioacademy.gr.
authors.forename: Anastasios
authors.identifier: 0000-0002-5490-3219
authors.initials: A
authors.lastname: Gaitanis
authors.affiliation: Research Center of Mathematics, Academy of Athens, Athens, Greece.|Radiochemical Studies Laboratory, Institute of Nuclear and Radiological Sciences & Technology, Energy & Safety (I.N.RA.S.T.E.S.), N.C.S.R. "Demokritos", Athens, Greece.
authors.forename: George A
authors.initials: GA
authors.lastname: Kastis
authors.affiliation: PET/CT Department and Small Animal PET/CT Unit, Centre for Clinical Research, Experimental Surgery & Translational Research, Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens, Greece.
authors.forename: Elena
authors.initials: E
authors.lastname: Vlastou
authors.affiliation: Radiochemical Studies Laboratory, Institute of Nuclear and Radiological Sciences & Technology, Energy & Safety (I.N.RA.S.T.E.S.), N.C.S.R. "Demokritos", Athens, Greece.
authors.forename: Penelope
authors.initials: P
authors.lastname: Bouziotis
authors.affiliation: Division of Clinical, Experimental Surgery, and Translational Research, Biomedical Research Foundation, Academy of Athens, 4 Soranou Efessiou Street, Athens, Greece.
authors.forename: Panayotis
authors.initials: P
authors.lastname: Verginis
authors.affiliation: PET/CT Department and Small Animal PET/CT Unit, Centre for Clinical Research, Experimental Surgery & Translational Research, Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens, Greece.
authors.forename: Constantinos D
authors.initials: CD
authors.lastname: Anagnostopoulos
mesh_terms: D000465:Algorithms; D000818:Animals; D004583:Electrons; D019788:Fluorodeoxyglucose F18 / Q000737:chemistry; D005710:Gallium Radioisotopes / Q000737:chemistry; D007091:Image Processing, Computer-Assisted; D019047:Phantoms, Imaging; D000072078:Positron Emission Tomography Computed Tomography / Q000295:instrumentation* / Q000592:standards*; D012015:Reference Standards; D059629:Signal-To-Noise Ratio; D014867:Water / Q000737:chemistry
chemical_list: D005710:Gallium Radioisotopes; D014867:Water; D019788:Fluorodeoxyglucose F18
keywords: 3D OSEM; Image quality; Mediso nanoScan; NEMA NU 4-2008; Small-animal PET/CT; Tera-Tomo 3D; Total level of regularization