title: Direct comparison study between FDG-PET and IMP-SPECT for diagnosing Alzheimer's disease using 3D-SSP analysis in the same patients.
abstract: OBJECTIVE
  The purpose of this study was to evaluate and compare the diagnostic ability of 2-[(18)F]-fluoro-2-deoxy-D: -glucose (FDG) positron emission tomography (PET) and N-isopropyl-p-(123)I iodoamphetamine single photon emission computed tomography (IMP-SPECT) using three-dimensional stereotactic surface projections (3D-SSP) in patients with moderate Alzheimer's disease (AD).
  
  
  METHODS
  FDG-PET and IMP-SPECT were performed within 3 months in 14 patients with probable moderate AD. Z-score maps of FDG-PET and IMP-SPECT images of a patient were obtained by comparison with data obtained from control subjects. Four expert physicians evaluated and graded the glucose hypometabolism and regional cerebral blood flow (rCBF), focusing in particular on the posterior cingulate gyri/precunei and parietotemporal regions, and determined the reliability for AD. Receiver operating characteristic (ROC) curves were applied to the results for clarification. To evaluate the correlation between two modalities, the regions of interest (ROIs) were set in the posterior cingulate gyri/precunei and parietotemporal region on 3D-SSP images, and mean Z-values were calculated.
  
  
  CONCLUSIONS
  No significant difference was observed in the area under the ROC curve (AUC) between FDG-PET and IMP-SPECT images (FDG-PET 0.95, IMP-SPECT 0.94). However, a significant difference (P < 0.05) was observed in the AUC for the posterior cingulate gyri/precuneus (FDG-PET 0.94, IMP-SPECT 0.81). The sensitivity and specificity of each modality were 86%, and 97% for FDG-PET and 70% and 100% for IMP-SPECT. We could find no significant difference between FDG-PET and IMP-SPECT in terms of diagnosing moderate AD using 3D-SSP. There was a high correlation between the two modalities in the parietotemporal region (Spearman's r = 0.82, P < 0.001). The correlation in the posterior cingulate gyri/precunei region was lower than that in the parietotemporal region (Spearman's r = 0.63, P < 0.016).
authors.affiliation: Department of Radiology, National Center for Geriatrics and Gerontology, 36-3 Gengo, Morioka-Cho, Ohbu, 474-8522, Japan. dr284@hotmail.com
authors.forename: Takashi
authors.initials: T
authors.lastname: Nihashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yatsuya
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Hayasaka
authors.forename: Rikio
authors.initials: R
authors.lastname: Kato
authors.forename: Shoji
authors.initials: S
authors.lastname: Kawatsu
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Arahata
authors.forename: Katsushige
authors.initials: K
authors.lastname: Iwai
authors.forename: Akinori
authors.initials: A
authors.lastname: Takeda
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Washimi
authors.forename: Kumiko
authors.initials: K
authors.lastname: Yoshimura
authors.forename: Kanako
authors.initials: K
authors.lastname: Mizuno
authors.forename: Takashi
authors.initials: T
authors.lastname: Kato
authors.forename: Shinji
authors.initials: S
authors.lastname: Naganawa
authors.forename: Kengo
authors.initials: K
authors.lastname: Ito
mesh_terms: D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D000983:Antipyrine / Q000031:analogs & derivatives; D019298:Glucose-6-Phosphate / Q000031:analogs & derivatives; D006801:Humans; D021621:Imaging, Three-Dimensional; D049268:Positron-Emission Tomography / Q000379:methods*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: C047515:2-fluoro-2-deoxyglucose-6-phosphate; D019298:Glucose-6-Phosphate; D000983:Antipyrine; C008135:iodoantipyrine