title: Scaling digital radiographs for templating in total hip arthroplasty using conventional acetate templates independent of calibration markers.
abstract: We describe a scaling method for templating digital radiographs using conventional acetate templates independent of template magnification without the need for a calibration marker. The mean magnification factor for the radiology department was determined (119.8%; range, 117%-123.4%). This fixed magnification factor was used to scale the radiographs by the method described. Thirty-two femoral heads on postoperative total hip arthroplasty radiographs were then measured and compared with the actual size. The mean absolute accuracy was within 0.5% of actual head size (range, 0%-3%) with a mean absolute difference of 0.16 mm (range, 0-1 mm; SD, 0.26 mm). Intraclass correlation coefficient showed excellent reliability for both interobserver and intraobserver measurements with intraclass correlation coefficient scores of 0.993 (95% CI, 0.988-0.996) for interobserver measurements and intraobserver measurements ranging between 0.990 and 0.993 (95% CI, 0.980-0.997).
authors: Orthopaedic Research Unit, Queensland University of Technology, The Prince Charles Hospital, Brisbane, Queensland, Australia.
authors: Christopher J
authors: CJ
authors: Brew
authors: Philip M
authors: PM
authors: Simpson
authors: Sarah L
authors: SL
authors: Whitehouse
authors: William
authors: W
authors: Donnelly
authors: Ross W
authors: RW
authors: Crawford
authors: Matthew J W
authors: MJ
authors: Hubble
mesh_terms: D000085:Acetates; D019644:Arthroplasty, Replacement, Hip / Q000379:methods* / Q000592:standards; D002138:Calibration / Q000592:standards; D005270:Femur Head / Q000000981:diagnostic imaging* / Q000601:surgery; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D015588:Observer Variation; D017755:Prosthesis Fitting / Q000379:methods* / Q000592:standards; D011856:Radiographic Image Enhancement / Q000379:methods* / Q000592:standards; D015203:Reproducibility of Results
chemical_list: D000085:Acetates