title: Concordance between 11C-PIB-PET and clinical diagnosis in a memory clinic.
abstract: BACKGROUND
  Today, ligands that bind to fibrillar β-amyloid are detectable by Positron Emission Tomography (PET) allowing for in vivo visualization for Abeta burden. However, amyloid plaques detection per se does not establish Alzheimer's Disease diagnosis. In this sense, the utility of amyloid imaging to improve clinical diagnosis was settled only for specific clinical scenarios and few studies have assessed amyloid molecular neuroimaging in a broader clinical setting. The aim of this study is to determine the frequency of PiB amyloid findings in different diagnostic syndromes grouped into high and low probability pre- test categories, taking into account pre-test clinical assumption of the presence of AD related pathology.
  
  
  METHODS
  144 patients were assigned into categories of high or low pretest probability according to clinical suspicion of AD pathology. The high probability group included: amnestic Mild Cognitive Impairment (MCI), amnestic and other domains MCI, Dementia of Alzheimer's Type (DAT), Posterior Cortical Atrophy (PCA), logopenic Primary Progressive Aphasia (PPA), Cerebral Amyloid Angiopathy and mixed dementia. The low assumption group included: normal controls, non-amnestic MCI, non-logopenic PPA and Frontotemporal Dementia (FTD).
  
  
  RESULTS
  Only normal controls and DAT patients (typical and atypical presentation) were the most consistent across clinical and molecular diagnostics. MCI, non-logopenic PPA and FTD were the syndromic diagnoses that most discrepancies were found.
  
  
  CONCLUSIONS
  This study demonstrates that detecting in vivo amyloid plaques by molecular imaging is considerably frequent in most of the dementia syndromes and shows that there are frequent discordance between molecular diagnosis and clinical assumption.
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina patriciochrem@gmail.com.
authors: Chrem Mendez
authors: CM
authors: Patricio
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Cohen
authors: C
authors: Gabriela
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Russo Maria
authors: RM
authors: Julieta
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Fernandez Suarez
authors: FS
authors: Marcos
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Nahas
authors: N
authors: Federico
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Russo
authors: R
authors: Griselda
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Wierszylo
authors: W
authors: Claudio
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Paz
authors: P
authors: Santiago
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Tabaschi
authors: T
authors: Leonardo
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Campos
authors: C
authors: Jorge
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Amengual
authors: A
authors: Alejandra
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Kremer
authors: K
authors: Janus
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Guinjoan
authors: G
authors: Salvador
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Leiguarda
authors: L
authors: Ramon
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Sevlever
authors: S
authors: Gustavo
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Vázquez
authors: V
authors: Silvia
authors: Ageing and Memory Center, Instituto de Investigaciones Neurologicas "Raúl Carrea" (FLENI), Buenos Aires, Argentina.
authors: Allegri
authors: A
authors: Ricardo
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis; D000647:Amnesia / Q000175:diagnosis*; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000814:Aniline Compounds; D018888:Aphasia, Primary Progressive / Q000175:diagnosis; D001284:Atrophy / Q000175:diagnosis; D052160:Benzothiazoles; D016657:Cerebral Amyloid Angiopathy / Q000175:diagnosis*; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology; D060825:Cognitive Dysfunction / Q000175:diagnosis*; D003704:Dementia / Q000175:diagnosis*; D005260:Female; D057174:Frontotemporal Lobar Degeneration / Q000175:diagnosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000592:standards*; D012189:Retrospective Studies; D013844:Thiazoles
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D016229:Amyloid beta-Peptides; D000814:Aniline Compounds; D052160:Benzothiazoles; D013844:Thiazoles
keywords: 11C-PIB-PET; amyloid; memory clinic; neuroimaging