florbetapir-f-18 and Intracranial-Hemorrhages

Sporadic cerebral amyloid angiopathy shows progressive amyloid-β deposition in the wall of small arterioles and capillaries of the leptomeninges and cerebral cortex.. To investigate whether amyloid load and distribution, assessed by florbetapir positron emission tomography (PET), differs between patients with probable CAA-related intracerebral hemorrhage (CAA-ICH) and mild cognitive impairment due to Alzheimer's disease (MCI-AD).. We assessed [18F]florbetapir uptake in 15 patients with probable CAA-ICH and 20 patients with MCI-AD patients. Global and regional florbetapir retention were assessed using standard uptake values ratio (SUVr) in region-based and voxel-wise approaches. Visual reading of florbetapir scans was performed for all participants. Group comparisons were performed using univariate and multivariate analysis.. Global florbetapir retention was lower in patients with CAA-ICH than MCI-AD (median SUVr, 1.33 [1.21-1.41] versus 1.44 [1.35-1.66]; p = 0.032). In the region-based analysis, regional florbetapir distribution was similar between the two groups. There was a trend for an increased occipital/global ratio in CAA-ICH patients compared to MCI-AD (p = 0.060). In the voxel-wise approach, two clusters, one in parietal regions and the other in temporal regions, had higher uptake in MCI-AD relative to CAA patients.. Patients with CAA-ICH had a lower global florbetapir PET burden than patients with MCI-AD. Relative florbetapir retention in the posterior regions tended to be higher in CAA patients in region-based analysis but was not statistically different between groups. Investigation on differences in amyloid deposits distribution between groups required a fine-grained voxel-wise analysis. In future studies, selective amyloid tracers are needed to differentiate vascular from parenchymal amyloid.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Aniline Compounds; Body Burden; Cerebral Amyloid Angiopathy; Cognitive Dysfunction; Ethylene Glycols; Female; Humans; Image Interpretation, Computer-Assisted; Intracranial Hemorrhages; Magnetic Resonance Imaging; Male; Middle Aged; Positron-Emission Tomography; Radiopharmaceuticals

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).. 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.. 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).. Focal hemosiderin deposits are relatively common in the ADNI cohort and are associated with β-amyloid load.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Amyloid beta-Peptides; Analysis of Variance; Aniline Compounds; Apolipoprotein E4; Cognition Disorders; Cohort Studies; Disease Progression; Ethylene Glycols; Female; Hemosiderosis; Humans; Intracranial Hemorrhages; Magnetic Resonance Imaging; Male; Positron-Emission Tomography; Time Factors