title: Cerebral microhemorrhage and brain β-amyloid in aging and Alzheimer disease.
abstract: OBJECTIVE
  Incidental cerebral microhemorrhage (MH) is frequently found in older individuals scanned with susceptibility-weighted MRI (SWI) or gradient-recalled echo MRI. MH have been linked with β-amyloid (Aβ) deposition using (11)C-Pittsburgh compound B (PiB) PET in Alzheimer disease (AD) and cerebral amyloid angiopathy (CAA). We hypothesized that Aβ deposition in asymptomatic elderly individuals is associated with lobar MH (LMH).
  
  
  METHODS
  This was a cross-sectional study of 84 elderly healthy controls (HC), 28 subjects with mild cognitive impairment (MCI), and 26 subjects with probable AD who underwent 3-T SWI and (11)C-PiB PET. (11)C-PiB cortical binding was quantified normalized to cerebellar cortex (standardized uptake value ratio [SUVR]) and scans classified as positive (PiB+) or negative (PiB-) by visual inspection. MH were manually counted and categorized by region and as lobar or nonlobar.
  
  
  RESULTS
  LMH were present in 30.8% of AD, 35.7% of MCI, and 19.1% of HC. The prevalence of LMH among PiB+ subjects was similar, regardless of clinical classification (AD 30.8%, MCI 38.9%, HC 41.4%, p > 0.7). HC with LMH had significantly higher mean neocortical SUVR (1.7 ± 0.5) than HC without LMH (1.3 ± 0.3, p ± 0.01). In HC, there was a positive correlation between number of LMH and SUVR, and between LMH and age. In HC, PiB+ (odds ratio [OR] 7.3, 95% confidence interval [CI] 1.6-33.7, p = 0.01) and age (OR 1.2, 95% CI 1.03-1.3, p = 0.02) both independently predicted the occurrence of LMH using logistic regression.
  
  
  CONCLUSIONS
  Asymptomatic Aβ deposition in older adults is strongly associated with LMH.
authors.affiliation: Department of Nuclear Medicine and Centre for PET, Austin Health, 145 Studley Road, Heidelberg, Victoria 3084, Australia. paul.yates@austin.org.au
authors.forename: P A
authors.initials: PA
authors.lastname: Yates
authors.forename: R
authors.initials: R
authors.lastname: Sirisriro
authors.forename: V L
authors.initials: VL
authors.lastname: Villemagne
authors.forename: S
authors.initials: S
authors.lastname: Farquharson
authors.forename: C L
authors.initials: CL
authors.lastname: Masters
authors.forename: C C
authors.initials: CC
authors.lastname: Rowe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology*; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000814:Aniline Compounds; D053327:Apolipoprotein E4 / Q000235:genetics; D052160:Benzothiazoles; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D001931:Brain Mapping; D002250:Carbon Radioisotopes; D002543:Cerebral Hemorrhage / Q000209:etiology*; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000000981:diagnostic imaging / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods; D011569:Psychiatric Status Rating Scales; D013844:Thiazoles
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D016229:Amyloid beta-Peptides; D000814:Aniline Compounds; D053327:Apolipoprotein E4; D052160:Benzothiazoles; D002250:Carbon Radioisotopes; D013844:Thiazoles