Year: 2006
Type: article
Abstract: The first human amyloid–beta imaging study using Pittsburgh Compound–B (PIB) was performed in Uppsala, Sweden, in February 2002. The preliminary report in July 2002 suggested that amyloid–beta could be successfully imaged and quantified using PIB–PET. Summarize key findings of amyloid–imaging studies using PIB over the past four years. Review of published papers and abstracts. Over a dozen institutions worldwide are performing PIB studies. We estimate that >500 PIB scans have been performed, without adverse effects. Approximately 100 PIB studies have been performed in Pittsburgh with MR–based co–registration and many included arterial sampling and sequential [O–15]water and FDG studies. PIB data is amenable to pharmacokinetic analysis by standard methods, in particular the Logan graphical method. Arterial input data are advantageous, but not absolutely required. Input can be derived from cerebellar or carotid reference regions. Late–summed standardized uptake value (SUV) methods also can be employed. Voxel–based (SPM) methods produce robust results as well. PIB retention correlates inversely to metabolism (FDG) in precuneus and frontal cortex: however FDG has a lower dynamic range. [O–15]Water studies show PIB retention is not strongly influenced by blood flow. In clinical studies, most normal controls show no evidence of cortical PIB retention, but ∼20% of those over age 65 show evidence of PIB retention using a DVR cutoff of 1.5 and verification by the regional pattern on the image. Neurocognitive testing has not demonstrated a clear relationship between cognitive performance and amyloid deposition in this small series, but work is ongoing. MCI subjects do not cluster between control and AD ranges. About ∼25% of MCI subjects showed no PIB retention (control–like) and ∼60% had AD–like PIB retention; the remainder were intermediate. Asymptomatic FAD subjects harboring PS–1 mutations show focal amyloid deposition in the striatum, suggesting this is a site of initiation for amyloid deposition in these Aβ–overproduction forms of AD. In contrast, initiation of amyloid deposition in late–onset AD may begin in the frontal or precuneus cortex. Early studies continue to suggest that amyloid imaging with PIB–PET is a safe and effective way to study amyloid deposits in AD.
Source: Alzheimer s & Dementia
Institution: University of Pittsburgh
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2745854201