title: Characteristic distributions of intracerebral hemorrhage-associated diffusion-weighted lesions.
abstract: OBJECTIVE
  To determine whether small diffusion-weighted imaging (DWI) lesions occur beyond the acute posthemorrhage time window in patients with intracerebral hemorrhage (ICH) and to characterize their spatial distribution in patients with lobar and deep cerebral hemorrhages.
  
  
  METHODS
  In this cross-sectional study, we retrospectively analyzed 458 MRI scans obtained in the acute (≤ 7 days after ICH) or nonacute (>14 days after ICH) phases from 392 subjects with strictly lobar (n = 276) and deep (n = 116) ICH (48.7% women; mean age 72.8 ± 11.7 years). DWI, apparent diffusion coefficient maps, fluid-attenuated inversion recovery, and T2* MRIs were reviewed for the presence and location of DWI lesions.
  
  
  RESULTS
  We identified 103 DWI hyperintense lesions on scans from 62 subjects, located mostly in lobar brain regions (90 of 103, 87.4%). The lesions were not uniformly distributed throughout the brain lobes; patients with strictly lobar ICH had relative overrepresentation of lesions in frontal lobe, and patients with deep ICH in parietal lobe (p = 0.002). Although the frequency of DWI lesions tended to be greater on scans performed within 7 days after ICH (39 of 214, 18.2%), they continued at high frequency in the nonacute period as well (23 of 178, 12.9%, odds ratio 1.5, 95% confidence interval 0.86-2.6 for acute vs nonacute). There was also no difference in frequency of lesions on acute and nonacute scans among 66 subjects with MRIs in both time periods (8 of 66 acute, 10 of 66 nonacute, odds ratio 0.77, 95% confidence interval 0.25-2.4).
  
  
  CONCLUSIONS
  The high frequency of DWI lesions beyond the acute post-ICH period and their characteristic distributions suggest that they are products of the small vessel diseases that underlie ICH.
authors.affiliation: J. Philip Kistler Stroke Research Center, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Eitan
authors.initials: E
authors.lastname: Auriel
authors.forename: Mahmut Edip
authors.initials: ME
authors.lastname: Gurol
authors.forename: Alison
authors.initials: A
authors.lastname: Ayres
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Dumas
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Schwab
authors.forename: Anastasia
authors.initials: A
authors.lastname: Vashkevich
authors.forename: Sergi
authors.initials: S
authors.lastname: Martinez-Ramirez
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rosand
authors.forename: Anand
authors.initials: A
authors.lastname: Viswanathan
authors.forename: Steven M
authors.initials: SM
authors.lastname: Greenberg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D002543:Cerebral Hemorrhage / Q000473:pathology*; D003430:Cross-Sectional Studies; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies