Rabinovici GD, Rosen HJ, Alkalay A, Trojanowski JQ, Grinberg LT, Huang EJ, Seeley WW, Miller BL, Jagust WJ.
PIB versus FDG PET in pathologically verified dementia.
Human Amyloid Imaging 2011 Meeting Abstracts. 2011 Jan 15;
Objective: To compare PIB and FDG PET to histopathology in a heterogeneous dementia population.
Methods: Thirteen dementia patients (mean age 67.8}10.0, MMSE 19.3}7.5) underwent [11C]PIB
and [18F]FDG PET. Clinical diagnoses included Alzheimer's disease (AD, N = 3) and the frontotemporal lobar
degeneration (FTLD) syndromes frontotemporal dementia (N = 4), semantic dementia (N = 3) and corticobasal
syndrome (CBS, N = 3). PIB DVR images (cerebellar reference) were visually rated by two investigators blinded
to clinical diagnosis as PIB-positive or negative. FDG scans (pons-normalized) were visually rated as consistent
with AD or FTLD. Histopathology was determined by autopsy (N = 11, 2.3)1.4 years after PET), biopsy (N = 1) or
presence of a pathogenic mutation (N = 1).
Results: Pathologic diagnoses included high-likelihood AD (N = 3), mixed AD/dementia with Lewy bodies (AD/
DLB, N = 1), FTLD-TDP (N = 5), Pickfs disease (N = 2) and corticobasal degeneration (CBD, N = 2). PIB Index (mean
DVR in frontal, parietal, lateral temporal and cingulate cortex) was higher in patients with AD pathology (1.43}0.38)
than in pathologically-confirmed FTLD (1.01}0.08, p Conclusions: Visual reads of PIB outperformed FDG in predicting histopathology in this small series. PIB visual
reads did not detect early amyloid pathology co-morbid with FTLD, which in this case enhanced specificity for
primary AD. Amyloid PET is likely to improve in vivo prediction of histopathology in dementia.
Acknowledgements: NIA K23-AG031861, R01-AG027859, P01-AG1972403, P50-AG023501, Alzheimer's
Association NIRG-07-59422, John Douglas French Alzheimer's Foundation.