title: Differential diagnosis in Alzheimer's disease and dementia with Lewy bodies via VMAT2 and amyloid imaging.
abstract: BACKGROUND
  The noninvasive evaluation of nigrostriatal dopaminergic integrity by PET can provide useful information for the differential diagnosis between dementia with Lewy bodies (DLB) and Alzheimer's disease (AD).
  
  
  OBJECTIVE
  To evaluate the diagnostic potential of imaging striatal monoaminergic terminal integrity with the novel vesicular monoamine transporter type 2 (VMAT2) radioligand [(18)F]AV-133 and PET to distinguish DLB from AD.
  
  
  METHODS
  Fifty participants [9 DLB, 11 AD, 20 Parkinson's disease (PD) and 10 healthy age-matched control subjects (HC)] underwent [(18)F]AV-133 PET studies. Additionally, 20 participants underwent amyloid imaging PET scans with either [(11)C]PiB or (18)F-florbetaben. VMAT2 density was calculated through normalized tissue uptake value ratios (R(T)) at 120-140 min after injection using the primary visual or the cerebellar cortex as reference region. Comparison of the R(T) for [(18)F]AV-133 was done between the different clinical diagnostic groups.
  
  
  RESULTS
  Significantly lower striatal VMAT2 densities were observed in DLB and PD when compared to AD and HC, especially in the posterior putamen. In contrast to PD and DLB, no reductions were observed in AD patients when compared to HC.
  
  
  CONCLUSIONS
  [(18)F]AV-133 allows assessment of nigrostriatal degeneration in Lewy body diseases. In contrast to amyloid imaging, VMAT2 imaging with [(18)F]AV-133 can robustly detect reductions of dopaminergic nigrostriatal afferents in DLB patients, assisting in the differential diagnosis from AD.
authors.affiliation: Mental Health Research Institute, University of Melbourne, Melbourne, Vic, Australia.
authors.forename: Victor L
authors.initials: VL
authors.lastname: Villemagne
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Okamura
authors.forename: Svetlana
authors.initials: S
authors.lastname: Pejoska
authors.forename: John
authors.initials: J
authors.lastname: Drago
authors.forename: Rachel S
authors.initials: RS
authors.lastname: Mulligan
authors.forename: Gaël
authors.initials: G
authors.lastname: Chételat
authors.forename: Graeme
authors.initials: G
authors.lastname: O'Keefe
authors.forename: Gareth
authors.initials: G
authors.lastname: Jones
authors.forename: Hank F
authors.initials: HF
authors.lastname: Kung
authors.forename: Michael
authors.initials: M
authors.lastname: Pontecorvo
authors.forename: Colin L
authors.initials: CL
authors.lastname: Masters
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Skovronsky
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Rowe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D000679:Amygdala / Q000000981:diagnostic imaging* / Q000473:pathology*; D000814:Aniline Compounds; D001931:Brain Mapping; D002250:Carbon Radioisotopes; D016022:Case-Control Studies; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D020961:Lewy Body Disease / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D013747:Tetrabenazine / Q000031:analogs & derivatives; D013844:Thiazoles; D050493:Vesicular Monoamine Transport Proteins / Q000378:metabolism*
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D000814:Aniline Compounds; D002250:Carbon Radioisotopes; D005462:Fluorine Radioisotopes; C493452:SLC18A2 protein, human; D013844:Thiazoles; D050493:Vesicular Monoamine Transport Proteins; C549477:florbenazine F 18; D013747:Tetrabenazine