title: The ART of loss: Abeta imaging in the evaluation of Alzheimer's disease and other dementias.
abstract: Molecular neuroimaging based on annihilation radiation tomographic (ART) techniques such as positron emission tomography (PET), in conjunction with related biomarkers in plasma and cerebrospinal fluid (CSF), are proving valuable in the early and differential diagnosis of Alzheimer's disease (AD). With the advent of new therapeutic strategies aimed at reducing beta-amyloid (Abeta) burden in the brain to potentially prevent or delay functional and irreversible cognitive loss, there is increased interest in developing agents that allow assessment of Abeta burden in vivo. Abeta burden as assessed by molecular imaging matches histopathological reports of Abeta plaque distribution in aging and dementia and appears more accurate than FDG for the diagnosis of AD. Abeta imaging is also a very powerful tool in the differential diagnosis of AD from fronto-temporal dementia (FTD). Although Abeta burden as assessed by PET does not correlate with measures of cognitive decline in AD, it does correlate with memory impairment and rate of memory decline in mild cognitive impairment (MCI) and healthy older subjects. Approximately 30% of asymptomatic controls present cortical (11)C-PiB retention. These observations suggest that Abeta deposition is not part of normal ageing, supporting the hypothesis that Abeta deposition occurs well before the onset of symptoms and is likely to represent preclinical AD. Further longitudinal observations are required to confirm this hypothesis and to better elucidate the role of Abeta deposition in the course of Alzheimer's disease.
authors.affiliation: Department of Nuclear Medicine, Centre for PET, Austin Health, 145 Studley Road, Heidelberg, Victoria 3084, Australia. villemagne@petnm.unimelb.edu.au
authors.forename: Victor L
authors.initials: VL
authors.lastname: Villemagne
authors.forename: Michelle T
authors.initials: MT
authors.lastname: Fodero-Tavoletti
authors.forename: Kerryn E
authors.initials: KE
authors.lastname: Pike
authors.forename: Roberto
authors.initials: R
authors.lastname: Cappai
authors.forename: Colin L
authors.initials: CL
authors.lastname: Masters
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Rowe
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000235:genetics / Q000473:pathology*; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D002250:Carbon Radioisotopes / Q000378:metabolism; D003704:Dementia / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000235:genetics / Q000473:pathology*; D003952:Diagnostic Imaging / Q000379:methods*; D006801:Humans; D011877:Radionuclide Imaging
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; D002250:Carbon Radioisotopes