title: Intracranial hemorrhage detection over time using susceptibility-weighted magnetic resonance imaging.
abstract: BACKGROUND
  The reliable detection of intracranial hemorrhages is important, but just 1 year after the hemorrhage onset it might be missed using T2-weighted spin-echo and gradient-echo sequences. Susceptibility-weighted imaging (SWI) is a new magnetic resonance imaging sequence that is extremely sensitive in hemorrhage detection and that might improve the detection of hemorrhages over time.
  
  
  OBJECTIVE
  To investigate whether the detectability of intracranial blood and its degradation products is independent of the time span after intracranial hemorrhage using SWI.
  
  
  METHODS
  Sixty-six consecutive patients (28 men, 38 women) with definitely known time point of intracranial hemorrhage and available SWI sequence (1.5 or 3 T) were analyzed retrospectively. Twenty-one patients had a SWI follow-up. All SWI images were assessed by two radiologists in consensus regarding hemorrhage visibility using a 5-point scale. Statistical analysis was performed using Spearman's correlation test.
  
  
  RESULTS
  Median time interval between hemorrhage and first available SWI measurement was 819 days (range, 0 days to 13.2 years). Nine of 66 patients had an isolated subarachnoid hemorrhage (iSAH) and were therefore analyzed separately. In eight of these nine patients the hemorrhage could clearly be detected, the remaining one had minor iSAH. Spearman analysis showed no significant correlation between time span and visibility (P = 0.660). In the remaining 57 patients (no iSAH) the hemorrhage was always visible achieving at least 3/5 points on the 5-point scale, and Spearman's analysis revealed only a weak correlation between time span and visibility (r = 0.493, P < 0.001).
  
  
  CONCLUSIONS
  The detectability of blood and its degradation products using SWI is reliably possible over a long period after intracranial hemorrhage.
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany Juliane.Schelhorn@uk-essen.de.
authors.forename: Juliane
authors.initials: J
authors.lastname: Schelhorn
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Gramsch
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany.
authors.forename: Cornelius
authors.initials: C
authors.lastname: Deuschl
authors.affiliation: Erwin L Hahn Institute for Magnetic Resonance Imaging, Essen, Germany Highfield and Hybrid MR Imaging, University Hospital Essen, Essen, Germany.
authors.forename: Harald H
authors.initials: HH
authors.lastname: Quick
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Nensa
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Moenninghoff
authors.affiliation: Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Schlamann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D020300:Intracranial Hemorrhages / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Intracranial hemorrhage; hemosiderin; magnetic resonance imaging (MRI); susceptibility-weighted imaging (SWI)