title: Imaging of amyloid beta in Alzheimer's disease with 18F-BAY94-9172, a novel PET tracer: proof of mechanism.
abstract: BACKGROUND
  Amyloid-beta (Abeta) plaque formation is a hallmark of Alzheimer's disease (AD) and precedes the onset of dementia. Abeta imaging should allow earlier diagnosis, but clinical application is hindered by the short decay half-life of current Abeta-specific ligands. (18)F-BAY94-9172 is an Abeta ligand that, due to the half-life of (18)F, is suitable for clinical use. We thus studied the effectiveness of this ligand in identifying patients with AD.
  
  
  METHODS
  15 patients with mild AD, 15 healthy elderly controls, and five individuals with frontotemporal lobar degeneration (FTLD) were studied. (18)F-BAY94-9172 binding was quantified by use of the standardised uptake value ratio (SUVR), which was calculated for the neocortex by use of the cerebellum as reference region. SUVR images were visually rated as normal or AD.
  
  
  RESULTS
  (18)F-BAY94-9172 binding matched the reported post-mortem distribution of Abeta plaques. All AD patients showed widespread neocortical binding, which was greater in the precuneus/posterior cingulate and frontal cortex than in the lateral temporal and parietal cortex. There was relative sparing of sensorimotor, occipital, and medial temporal cortex. Healthy controls and FTLD patients showed only white-matter binding, although three controls and one FTLD patient had mild uptake in frontal and precuneus cortex. At 90-120 min after injection, higher neocortical SUVR was observed in AD patients (2.0 [SD 0.3]) than in healthy controls (1.3 [SD 0.2]; p<0.0001) or FTLD patients (1.2 [SD 0.2]; p=0.009). Visual interpretation was 100% sensitive and 90% specific for detection of AD.
  
  
  CONCLUSIONS
  (18)F-BAY94-9172 PET discriminates between AD and FTLD or healthy controls and might facilitate integration of Abeta imaging into clinical practice.
authors.affiliation: Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, Victoria, Australia. christopher.rowe@austin.org.au
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Rowe
authors.forename: Uwe
authors.initials: U
authors.lastname: Ackerman
authors.forename: William
authors.initials: W
authors.lastname: Browne
authors.forename: Rachel
authors.initials: R
authors.lastname: Mulligan
authors.forename: Kerryn L
authors.initials: KL
authors.lastname: Pike
authors.forename: Graeme
authors.initials: G
authors.lastname: O'Keefe
authors.forename: Henry
authors.initials: H
authors.lastname: Tochon-Danguy
authors.forename: Gordon
authors.initials: G
authors.lastname: Chan
authors.forename: Salvatore U
authors.initials: SU
authors.lastname: Berlangieri
authors.forename: Gareth
authors.initials: G
authors.lastname: Jones
authors.forename: Kerryn L
authors.initials: KL
authors.lastname: Dickinson-Rowe
authors.forename: Hank P
authors.initials: HP
authors.lastname: Kung
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Mei Ping
authors.initials: MP
authors.lastname: Kung
authors.forename: Daniel
authors.initials: D
authors.lastname: Skovronsky
authors.forename: Thomas
authors.initials: T
authors.lastname: Dyrks
authors.forename: Gerhard
authors.initials: G
authors.lastname: Holl
authors.forename: Sabine
authors.initials: S
authors.lastname: Krause
authors.forename: Matthias
authors.initials: M
authors.lastname: Friebe
authors.forename: Lutz
authors.initials: L
authors.lastname: Lehman
authors.forename: Stefanie
authors.initials: S
authors.lastname: Lindemann
authors.forename: Ludger M
authors.initials: LM
authors.lastname: Dinkelborg
authors.forename: Colin L
authors.initials: CL
authors.lastname: Masters
authors.forename: Victor L
authors.initials: VL
authors.lastname: Villemagne
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000814:Aniline Compounds / Q000138:chemical synthesis; D001921:Brain / Q000000981:diagnostic imaging*; D003704:Dementia / Q000175:diagnosis / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007553:Isotope Labeling; D008297:Male; D008875:Middle Aged; D058225:Plaque, Amyloid / Q000000981:diagnostic imaging / Q000378:metabolism; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000138:chemical synthesis; D013267:Stilbenes / Q000138:chemical synthesis
chemical_list: D016229:Amyloid beta-Peptides; D000814:Aniline Compounds; D019275:Radiopharmaceuticals; D013267:Stilbenes; C527756:4-(N-methylamino)-4'-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)stilbene