title: Equal sensitivity of early and late scans after injection of FDG for the detection of Alzheimer pattern: an analysis of 3D PET data from J-ADNI, a multi-center study.
abstract: OBJECTIVE
  To determine the optimal accumulation time for three-dimensional positron emission tomography (3D-PET) with (18)F-2-fluoro-2-deoxy-D-glucose ((18)F-FDG) to detect the brain uptake pattern typical of Alzheimer's disease (AD).
  
  
  METHODS
  Patients with mild AD or amnestic mild cognitive impairment (MCI) and normal control subjects were recruited in the Japanese Alzheimer's disease neuroimaging initiative and examined with a PET scan during the 30-60 min after FDG injection. Three independent blinded experts interpreted the 30- to 60-min sum images, and images of patients with AD and MCI presenting AD patterns and normal subjects presenting normal patterns were used in the analysis. Early-scan (ES) and late-scan (LS) images were obtained from the data acquired at 30-35 min and 55-60 min after the injection, respectively. Separate target regions of interest (ROI) for ES and LS were defined as areas of significant reductions in the posterior cingulate and parietotemporal lobe in both hemispheres from the results of an initial cohort with 21 patients (AD 16, MCI 5) and 19 controls. A subsequent sample of 36 (AD 9, MCI 27) patients and 38 controls were used to compare the diagnostic capability of ES and LS using Z scores within the target ROI in individual statistical parametric mapping analysis.
  
  
  RESULTS
  Compared to LS, ES showed lower activity in the frontal lobes and higher activity in the venous sinus than LS; however, the diagnostic capability of ES and LS did not significantly differ (sensitivity 0.97 and 0.97, specificity 0.82 and 0.84, area under the receiver-operating characteristic curve 0.96 and 0.97, respectively).
  
  
  CONCLUSIONS
  For a qualitative diagnosis of the AD pattern in 3D FDG-PET, results of ES were equivalent to those of LS. ES may be an option to shorten the entire PET procedure time, particularly in diagnosing early stages of AD.
authors.affiliation: J-ADNI PET core. r_takahashi@hwc.or.jp
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Takahashi
authors.forename: Kazunari
authors.initials: K
authors.lastname: Ishii
authors.forename: Michio
authors.initials: M
authors.lastname: Senda
authors.forename: Kengo
authors.initials: K
authors.lastname: Ito
authors.forename: Kenji
authors.initials: K
authors.lastname: Ishii
authors.forename: Takashi
authors.initials: T
authors.lastname: Kato
authors.forename: Yoko
authors.initials: Y
authors.lastname: Makishi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Nishio
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Ikari
authors.forename: Takeshi
authors.initials: T
authors.lastname: Iwatsubo
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000706:statistics & numerical data*; D007275:Injections, Intravenous; D007564:Japan / Q000453:epidemiology; D008297:Male; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D015995:Prevalence; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18