hide
Free keywords:
-
Abstract:
Deposition of beta-amyloid (Aß) peptide in the brain is a pathological hallmark of Alzheimer's disease (AD) and the regional extent of Aß accumulation can be assessed non invasively by Pittsburgh Compound-B amyloid imaging (PiB-PET). MRI at high field-strength of 7 Tesla (7T) provides significantly increased signal to noise ratios and thus may provide the specificity needed to identify signatures of potential Aß associated regional neurotoxicity. A particular goal of this project is to assess regional effects of Aß in asymptomatic individuals at increased risk for AD.
A study population consisting of asymptomatic individuals at increased risk for AD (age > 60 years) and individuals with mild cognitive impairment (MCI) has been administered PiB-PET and a neuropsychological battery testing individual cognitive performance. Based on regional intensity of the PiB-PET late frame signals, subgroups were formed reflecting the individual level of regional Aß-deposition. In addition 7T MRI sequences are used to acquire functional and metabolic correlates of neuronal stress, including BOLD resting state functional MRI (rs-fMRI), Magnetic Resonance Spectroscopic Imaging (MRSI), gradient echo susceptibility weighted imaging (T2*) and structural MRI (MPRAGE). Regional PiB-intensity is tested for correlations with MRI-contrasts and also for relationships with individual cognitive performance-levels.
This study will provide evidence regarding the applicability of MRI at 7T to identify amyloid deposition associated neuronal stress and potentially increased risk for AD. Preliminary data will be presented, including first results indicating effects on functional network integrity (rs-fMRI), regional iron deposition and calcification (T2*), as well as concentrations of brain metabolites (MRSI).