title: Virtual reality, ultrasound-guided liver biopsy simulator: development and performance discrimination.
abstract: OBJECTIVE
  The aim of this article was to identify and prospectively investigate simulated ultrasound-guided targeted liver biopsy performance metrics as differentiators between levels of expertise in interventional radiology.
  
  
  METHODS
  Task analysis produced detailed procedural step documentation allowing identification of critical procedure steps and performance metrics for use in a virtual reality ultrasound-guided targeted liver biopsy procedure. Consultant (n=14; male=11, female=3) and trainee (n=26; male=19, female=7) scores on the performance metrics were compared. Ethical approval was granted by the Liverpool Research Ethics Committee (UK). Independent t-tests and analysis of variance (ANOVA) investigated differences between groups.
  
  
  RESULTS
  Independent t-tests revealed significant differences between trainees and consultants on three performance metrics: targeting, p=0.018, t=-2.487 (-2.040 to -0.207); probe usage time, p = 0.040, t=2.132 (11.064 to 427.983); mean needle length in beam, p=0.029, t=-2.272 (-0.028 to -0.002). ANOVA reported significant differences across years of experience (0-1, 1-2, 3+ years) on seven performance metrics: no-go area touched, p=0.012; targeting, p=0.025; length of session, p=0.024; probe usage time, p=0.025; total needle distance moved, p=0.038; number of skin contacts, p<0.001; total time in no-go area, p=0.008. More experienced participants consistently received better performance scores on all 19 performance metrics.
  
  
  CONCLUSIONS
  It is possible to measure and monitor performance using simulation, with performance metrics providing feedback on skill level and differentiating levels of expertise. However, a transfer of training study is required.
authors.affiliation: Manchester Business School, University of Manchester, UK. sheena.johnson@mbs.ac.uk
authors.forename: S J
authors.initials: SJ
authors.lastname: Johnson
authors.forename: C M
authors.initials: CM
authors.lastname: Hunt
authors.forename: H M
authors.initials: HM
authors.lastname: Woolnough
authors.forename: M
authors.initials: M
authors.lastname: Crawshaw
authors.forename: C
authors.initials: C
authors.lastname: Kilkenny
authors.forename: D A
authors.initials: DA
authors.lastname: Gould
authors.forename: A
authors.initials: A
authors.lastname: England
authors.forename: A
authors.initials: A
authors.lastname: Sinha
authors.forename: P F
authors.initials: PF
authors.lastname: Villard
mesh_terms: D001706:Biopsy / Q000379:methods; D002983:Clinical Competence; D003198:Computer Simulation; D004521:Educational Measurement / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008099:Liver / Q000473:pathology*; D008297:Male; D011446:Prospective Studies; D015642:Radiology, Interventional / Q000592:standards*; D018084:Ultrasonography, Interventional; D014584:User-Computer Interface