title: Phantom criteria for qualification of brain FDG and amyloid PET across different cameras.
abstract: BACKGROUND
  While fluorodeoxyglucose (FDG) and amyloid PET is valuable for patient management, research, and clinical trial of therapeutics on Alzheimer's disease, the specific details of the PET scanning method including the PET camera model type influence the image quality, which may further affect the interpretation of images and quantitative capabilities. To make multicenter PET data reliable and to establish PET scanning as a universal diagnostic technique and a verified biomarker, we have proposed phantom test procedures and criteria for optimizing image quality across different PET cameras.
  
  
  RESULTS
  As the method, four physical parameters (resolution, gray-white contrast, uniformity, and image noise) were selected as essential to image quality for brain FDG and amyloid PET and were measured with a Hoffman 3D brain phantom and a uniform cylindrical phantom on a total of 12 currently used PET models. The phantom radioactivity and acquisition time were determined based on the standard scanning protocol for each PET drug (FDG,11C-PiB,18F-florbetapir, and18F-flutemetamol). Reconstruction parameters were either determined based on the methods adopted in ADNI, J-ADNI, and other research and clinical trials or optimized based on measured phantom image parameters under various reconstruction conditions. As the result, phantom test criteria were proposed as follows: (i) 8 mm FWHM or better resolution and (ii) gray/white %contrast ≥55 % with the Hoffman 3D brain phantom and (iii) SD of 51 small region of interests (ROIs) ≤0.0249 (equivalent to 5 % variation) for uniformity and (iv) image noise (SD/mean) ≤15 % for a large ROI with the uniform cylindrical phantom. These criteria provided image quality conforming to those multicenter clinical studies and were also achievable with most of the PET cameras that are currently used.
  
  
  CONCLUSIONS
  The proposed phantom test criteria facilitate standardization and qualification of brain FDG and amyloid PET images and deserve further evaluation by future multicenter clinical studies.
authors.affiliation: Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2, Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan. ikari@fbri.org.
authors.forename: Yasuhiko
authors.identifier: http://orcid.org/0000-0001-8728-5130
authors.initials: Y
authors.lastname: Ikari
authors.affiliation: Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2, Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Akamatsu
authors.affiliation: Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2, Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Nishio
authors.affiliation: Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ishii
authors.affiliation: Department of Clinical and Experimental Neuroimaging, National Center for Geriatrics and Gerontology, Obu, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Ito
authors.affiliation: Department of Neuropathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Iwatsubo
authors.affiliation: Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2, Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan. senda@fbri.org.
authors.forename: Michio
authors.initials: M
authors.lastname: Senda
keywords: Amyloid PET; Brain FDG-PET; Image quality; Multicenter study; Standardization