Background: Prevalence and risk factors for focal hemosiderin deposits are important considerations when planning amyloid-modifying trials for treatment and prevention of Alzheimer's disease (AD).
Methods: Subjects were cognitively normal (n = 171), early-mild cognitive impairment (MCI) (n = 240), late-MCI (n = 111), and AD (n = 40) from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Microhemorrhages and superficial siderosis were assessed at baseline and on all available MRIs at 3, 6, and 12 months. β-amyloid load was assessed with (18)F-florbetapir positron emission tomography.
Results: Prevalence of superficial siderosis was 1% and prevalence of microhemorrhages was 25% increasing with age (P < .001) and β-amyloid load (P < .001). Topographic densities of microhemorrhages were highest in the occipital lobes and lowest in the deep/infratentorial regions. A greater number of microhemorrhages at baseline was associated with a greater annualized rate of additional microhemorrhages by last follow-up (rank correlation = 0.49; P < .001).
Conclusions: Focal hemosiderin deposits are relatively common in the ADNI cohort and are associated with β-amyloid load.
Keywords: ADNI; Alzheimer's disease; Amyloid; Early mild cognitive impairment; Florbetapir; MRI; Microhemorrhage; Mild cognitive impairment; PET; Superficial siderosis.
Copyright © 2013 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.