title: Measurement of perihematomal edema in intracerebral hemorrhage.
abstract: OBJECTIVE
  Perihematomal edema (PHE) is a marker of secondary injury in intracerebral hemorrhage (ICH). PHE measurement on computed tomography (CT) is challenging, and the principles used to detect PHE have not been described fully. We developed a systematic approach for CT-based measurement of PHE.
  
  
  METHODS
  Two independent raters measured PHE volumes on baseline and 24-hour post-ICH CT scans of 20 primary supratentorial ICH subjects. Boundaries were outlined with an edge-detection tool and adjusted after inspection of the 3 orthogonal planes. PHE was delineated with the additional principle that it should be (a) more hypodense than the corresponding area in the contralateral hemisphere and (b) most hypodense immediately surrounding the hemorrhage. We examined intra- and interrater reliability using intraclass correlation coefficients and Bland-Altman plots for interrater consistency. CT-based PHE was also compared using magnetic resonance imaging-based PHE detection for 18 subjects.
  
  
  RESULTS
  Median PHE volumes were 22.7 cc at baseline and 20.4 cc at 24 hours post-ICH. There were no statistically significant differences in PHE measurements between raters. Interrater and intrarater reliability for PHE were excellent. At baseline and 24 hours, interrater intraclass correlation coefficients were 0.98 (0.96-1.00) and 0.98 (0.97-1.00); intrarater intraclass correlation coefficients were 0.99 (0.99-1.00) and 0.99 (0.98-1.00). Bland-Altman analysis showed the bias for PHE measurements at baseline and 24 hours, -0.5 cc (SD, 5.4) and -3.2 cc (SD, 5.0), was acceptably small. PHE volumes determined by CT and magnetic resonance imaging were similar (23.9±16.9 cc versus 23.9±16.0 cc, R(2) = 0.98, P<0.0001).
  
  
  CONCLUSIONS
  Our method measures PHE with excellent reliability at baseline and 24 hours post-ICH.
authors.affiliation: From the Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale University School of Medicine, New Haven, CT (S.U., L.A.B., D.W.G., K.N.S.); Center for Human Genetic Research, Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (A.V., A.M.A., T.W.K.B., W.T.K., J.R.); and Stroke Division, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA (M.H.S.).
authors.forename: Sebastian
authors.initials: S
authors.lastname: Urday
authors.affiliation: From the Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale University School of Medicine, New Haven, CT (S.U., L.A.B., D.W.G., K.N.S.); Center for Human Genetic Research, Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (A.V., A.M.A., T.W.K.B., W.T.K., J.R.); and Stroke Division, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA (M.H.S.).
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Beslow
authors.affiliation: From the Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale University School of Medicine, New Haven, CT (S.U., L.A.B., D.W.G., K.N.S.); Center for Human Genetic Research, Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (A.V., A.M.A., T.W.K.B., W.T.K., J.R.); and Stroke Division, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA (M.H.S.).
authors.forename: David W
authors.initials: DW
authors.lastname: Goldstein
authors.affiliation: From the Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale University School of Medicine, New Haven, CT (S.U., L.A.B., D.W.G., K.N.S.); Center for Human Genetic Research, Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (A.V., A.M.A., T.W.K.B., W.T.K., J.R.); and Stroke Division, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA (M.H.S.).
authors.forename: Anastasia
authors.initials: A
authors.lastname: Vashkevich
authors.affiliation: From the Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale University School of Medicine, New Haven, CT (S.U., L.A.B., D.W.G., K.N.S.); Center for Human Genetic Research, Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (A.V., A.M.A., T.W.K.B., W.T.K., J.R.); and Stroke Division, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA (M.H.S.).
authors.forename: Alison M
authors.initials: AM
authors.lastname: Ayres
authors.affiliation: From the Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale University School of Medicine, New Haven, CT (S.U., L.A.B., D.W.G., K.N.S.); Center for Human Genetic Research, Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (A.V., A.M.A., T.W.K.B., W.T.K., J.R.); and Stroke Division, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA (M.H.S.).
authors.forename: Thomas W K
authors.initials: TW
authors.lastname: Battey
authors.affiliation: From the Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale University School of Medicine, New Haven, CT (S.U., L.A.B., D.W.G., K.N.S.); Center for Human Genetic Research, Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (A.V., A.M.A., T.W.K.B., W.T.K., J.R.); and Stroke Division, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA (M.H.S.).
authors.forename: Magdy H
authors.initials: MH
authors.lastname: Selim
authors.affiliation: From the Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale University School of Medicine, New Haven, CT (S.U., L.A.B., D.W.G., K.N.S.); Center for Human Genetic Research, Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (A.V., A.M.A., T.W.K.B., W.T.K., J.R.); and Stroke Division, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA (M.H.S.).
authors.forename: W Taylor
authors.initials: WT
authors.lastname: Kimberly
authors.affiliation: From the Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale University School of Medicine, New Haven, CT (S.U., L.A.B., D.W.G., K.N.S.); Center for Human Genetic Research, Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (A.V., A.M.A., T.W.K.B., W.T.K., J.R.); and Stroke Division, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA (M.H.S.).
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rosand
authors.affiliation: From the Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale University School of Medicine, New Haven, CT (S.U., L.A.B., D.W.G., K.N.S.); Center for Human Genetic Research, Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (A.V., A.M.A., T.W.K.B., W.T.K., J.R.); and Stroke Division, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA (M.H.S.). kevin.sheth@yale.edu.
authors.forename: Kevin N
authors.initials: KN
authors.lastname: Sheth
mesh_terms: D000328:Adult; D001929:Brain Edema / Q000000981:diagnostic imaging*; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging*; D006406:Hematoma / Q000150:complications / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009485:Neuroradiography / Q000379:methods* / Q000592:standards; D015203:Reproducibility of Results
keywords: computed tomography; intracerebral hemorrhage