title: Radiopacity of intracerebral hemorrhage correlates with perihemorrhagic edema.
abstract: BACKGROUND
  Experimental evidence indicates that iron plays a key role in edema formation after intracerebral hemorrhage (ICH). We investigated the relationship between ICH radiopacity on CT as a marker of hematoma iron content and perihemorrhagic edema (PHE) after ICH.
  
  
  METHODS
  We retrospectively investigated patients with spontaneous lobar and ganglionic supratentorial ICH who received follow-up CT scans during the first 7days after symptom onset (d1, d2-4, d5-7). Measurements of ICH and edema volumes were taken using a semiautomatic threshold-based volumetric algorithm. Radiopacity of the blood clot was determined using the mean Hounsfield unit (HU) count of the ICH.
  
  
  RESULTS
  A total of 117 patients aged 71.92±11.55years with spontaneous ICH (34.63±32.44ml) were included in the analysis. Mean ICH radiopacity was 59.7±3.4HU. We found significantly larger relative PHE at d2-4 (1.7±0.9 vs. 1.3±0.8; P=0.032) and d5-7 (2.0±1.3 vs. 1.3±0.9; P=0.007) and larger peak relative PHE (2.3±1.6 vs. 1.6±1.1; P=0.006) in patients with ICH radiopacity >60HU (n=59), as compared to patients with ICH radiopacity <60HU (n=58).
  
  
  CONCLUSIONS
  Higher ICH radiopacity, reflecting higher in vivo hematoma iron content, is associated with more PHE after ICH.
authors.affiliation: Department of Neurology, University of Erlangen-Nuremberg, Erlangen, Germany. ingrid.wagner@uk-erlangen.de
authors.forename: I
authors.initials: I
authors.lastname: Wagner
authors.forename: B
authors.initials: B
authors.lastname: Volbers
authors.forename: M J
authors.initials: MJ
authors.lastname: Hilz
authors.forename: S
authors.initials: S
authors.lastname: Schwab
authors.forename: A
authors.initials: A
authors.lastname: Doerfler
authors.forename: D
authors.initials: D
authors.lastname: Staykov
mesh_terms: D000368:Aged; D001929:Brain Edema / Q000000981:diagnostic imaging* / Q000209:etiology / Q000378:metabolism; D002543:Cerebral Hemorrhage / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007501:Iron / Q000378:metabolism; D008297:Male; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D007501:Iron