title: Inter-observer agreement between 2-dimensional CT versus 3-dimensional I-Space model in the Diagnosis of Occult Scaphoid Fractures.
abstract: BACKGROUND
  The I-Space is a radiological imaging system in which Computed Tomography (CT)-scans can be evaluated as a three dimensional hologram. The aim of this study is to analyze the value of virtual reality (I-Space) in diagnosing acute occult scaphoid fractures.
  
  
  METHODS
  A convenient cohort of 24 patients with a CT-scan from prior studies, without a scaphoid fracture on radiograph, yet high clinical suspicion of a fracture, were included in this study. CT-scans were evaluated in the I-Space by 7 observers of which 3 observers assessed the scans in the I-Space twice. The observers in this study assessed in the I-Space whether the patient had a scaphoid fracture. The kappa value was calculated for inter- and intra-observer agreement.
  
  
  RESULTS
  The Kappa value varied from 0.11 to 0.33 for the first assessment. For the three observers who assessed the CT-scans twice; observer 1 improved from a kappa of 0.33 to 0.50 (95% CI 0.26-0.74,P=0.01), observer 2 from 0.17 to 0.78 (95% CI 0.36-1.0,P<0.001), and observer 3 from 0.11 to 0.24 (95% CI 0.0-0.77,P=0.24).
  
  
  CONCLUSIONS
  Following our findings the I-Space has a fast learning curve and has a potential place in the diagnostic modalities for suspected scaphoid fractures.
authors.affiliation: Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Boston, USA.
authors.forename: Tessa
authors.initials: T
authors.lastname: Drijkoningen
authors.affiliation: Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Boston, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Knoter
authors.affiliation: Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Boston, USA.
authors.forename: Emile G
authors.initials: EG
authors.lastname: Coerkamp
authors.affiliation: Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Boston, USA.
authors.forename: Anton H J
authors.initials: AH
authors.lastname: Koning
authors.affiliation: Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Boston, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Rhemrev
authors.affiliation: Orthopaedic Hand and Upper Extremity Service, Massachusetts General Hospital, Boston, USA.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Beeres
keywords: 3D Imaging; Occult fracture; Scaphoid; Virtual Reality