title: Semi-automated trajectory analysis of deep ballistic penetrating brain injury.
abstract: BACKGROUND
  Penetrating head injuries (PHIs) are common in combat operations and most have visible wound paths on computed tomography (CT).
  
  
  OBJECTIVE
  We assess agreement between an automated trajectory analysis-based assessment of brain injury and manual tracings of encephalomalacia on CT.
  
  
  METHODS
  We analyzed 80 head CTs with ballistic PHI from the Institutional Review Board approved Vietnam head injury registry. Anatomic reports were generated from spatial coordinates of projectile entrance and terminal fragment location. These were compared to manual tracings of the regions of encephalomalacia. Dice's similarity coefficients, kappa, sensitivities, and specificities were calculated to assess agreement. Times required for case analysis were also compared.
  
  
  RESULTS
  Results show high specificity of anatomic regions identified on CT with semiautomated anatomical estimates and manual tracings of tissue damage. Radiologist's and medical students' anatomic region reports were similar (Kappa 0.8, t-test p < 0.001). Region of probable injury modeling of involved brain structures was sensitive (0.7) and specific (0.9) compared with manually traced structures. Semiautomated analysis was 9-fold faster than manual tracings.
  
  
  CONCLUSIONS
  Our region of probable injury spatial model approximates anatomical regions of encephalomalacia from ballistic PHI with time-saving over manual methods. Results show potential for automated anatomical reporting as an adjunct to current practice of radiologist/neurosurgical review of brain injury by penetrating projectiles.
authors.affiliation: Department of Radiology, National Institutes of Health, 10 Center Drive MSC 1440, Bethesda, MD 20892-1440, USA.
authors.forename: Les
authors.initials: L
authors.lastname: Folio
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Solomon
authors.forename: Nadia
authors.initials: N
authors.lastname: Biassou
authors.forename: Tatjana
authors.initials: T
authors.lastname: Fischer
authors.forename: Jenny
authors.initials: J
authors.lastname: Dworzak
authors.forename: Vanessa
authors.initials: V
authors.lastname: Raymont
authors.forename: Ninet
authors.initials: N
authors.lastname: Sinaii
authors.forename: Eric M
authors.initials: EM
authors.lastname: Wassermann
authors.forename: Jordan
authors.initials: J
authors.lastname: Grafman
mesh_terms: D044709:Forensic Ballistics / Q000379:methods*; D020197:Head Injuries, Penetrating / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014948:Wounds, Gunshot / Q000000981:diagnostic imaging*