title: Performance characteristics of methods for quantifying spontaneous intracerebral haemorrhage: data from the Efficacy of Nitric Oxide in Stroke (ENOS) trial.
abstract: BACKGROUND
  Poor prognosis after intracerebral haemorrhage (ICH) is related to haemorrhage characteristics. Along with developing therapeutic interventions, we sought to understand the performance of haemorrhage descriptors in large clinical trials.
  
  
  METHODS
  Clinical and neuroimaging data were obtained for 548 participants with ICH from the Efficacy of Nitric Oxide in Stroke (ENOS) trial. Independent observers performed visual categorisation of the largest diameter, measured volume using ABC/2, modified ABC/2, semiautomated segmentation (SAS), fully automatic measurement methods; shape, density and intraventricular haemorrhage were also assessed. Intraobserver and interobserver reliability were determined for these measures.
  
  
  RESULTS
  ICH volume was significantly different among standard ABC/2, modified ABC/2 and SAS: (mean) 12.8 (SD 16.3), 8.9 (9.2), 12.8 (13.1) cm(3), respectively (p<0.0001). There was excellent agreement for haemorrhage volume (n=193): ABC/2 intraobserver intraclass correlation coefficient (ICC) 0.96-0.97, interobserver ICC 0.88; modified ABC/2 intraobserver ICC 0.95-0.97, interobserver ICC 0.91; SAS intraobserver ICC 0.95-0.99, interobserver ICC 0.93; largest diameter: (visual) interadjudicator ICC 0.82, (visual vs measured) adjudicator vs observer ICC 0.71; shape intraobserver ICC 0.88 interobserver ICC 0.75; density intraobserver ICC 0.86, interobserver ICC 0.73. Graeb score (mean 3.53) and modified Graeb (5.22) scores were highly correlated. Using modified ABC/2, ICH volume was underestimated in regular (by 2.2-2.5 cm(3), p<0.0001) and irregular-shaped haemorrhages (by 4.8-4.9 cm(3), p<0.0001). Fully automated measurement of haemorrhage volume was possible in only 5% of cases.
  
  
  CONCLUSIONS
  Formal measurement of haemorrhage characteristics and visual estimates are reproducible. The standard ABC/2 method is superior to the modified ABC/2 method for quantifying ICH volume.
  
  
  BACKGROUND
  ISRCTN9941422.
authors.affiliation: Stroke, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: Kailash
authors.initials: K
authors.lastname: Krishnan
authors.affiliation: Stroke, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: Siti F
authors.initials: SF
authors.lastname: Mukhtar
authors.affiliation: Stroke, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: James
authors.initials: J
authors.lastname: Lingard
authors.affiliation: Stroke, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: Aimee
authors.initials: A
authors.lastname: Houlton
authors.affiliation: Stroke, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Walker
authors.affiliation: Stroke, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: Tanya
authors.initials: T
authors.lastname: Jones
authors.affiliation: Stroke, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: Nikola
authors.initials: N
authors.lastname: Sprigg
authors.affiliation: School of Pathology and Laboratory Medicine, The University of Western Australia, Nedlands, Australia.
authors.forename: Lesley A
authors.initials: LA
authors.lastname: Cala
authors.affiliation: Department of Medical Imaging, College of Medicine, The University of Arizona, Arizona, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Becker
authors.affiliation: Radiological Sciences Research Group, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Dineen
authors.affiliation: Department of Neuroradiology, Nottingham University Hospitals, Queen's Medical Centre, Nottingham, UK.
authors.forename: Panos
authors.initials: P
authors.lastname: Koumellis
authors.affiliation: Stroke Centre, Ospedale Sacro Cuore Via Sempreboni, Verona, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Adami
authors.affiliation: Division of Neuroimaging Sciences, Centre for Clinical Brain Sciences, Western General Hospital, Edinburgh, UK.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Casado
authors.affiliation: Stroke, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
authors.forename: Philip M W
authors.initials: PM
authors.lastname: Bath
authors.affiliation: Division of Neuroimaging Sciences, Centre for Clinical Brain Sciences, Western General Hospital, Edinburgh, UK.
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Wardlaw
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D020299:Intracranial Hemorrhage, Hypertensive / Q000175:diagnosis* / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging; D009569:Nitric Oxide / Q000627:therapeutic use*; D015588:Observer Variation; D011379:Prognosis; D011446:Prospective Studies; D020521:Stroke / Q000175:diagnosis* / Q000188:drug therapy*; D014057:Tomography, X-Ray Computed; D014665:Vasodilator Agents / Q000627:therapeutic use*
chemical_list: D014665:Vasodilator Agents; D009569:Nitric Oxide
keywords: RANDOMISED TRIALS; STROKE