title: Image quality of cone beam computed tomography for evaluation of extremity fractures in the presence of metal hardware: visual grading characteristics analysis.
abstract: OBJECTIVE
  To evaluate image quality and interobserver reliability of a novel cone-beam CT (CBCT) scanner in comparison with plain radiography for assessment of fracture healing in the presence of metal hardware.
  
  
  METHODS
  In this prospective institutional review board-approved Health Insurance Portability and Accountability Act of 1996-complaint study, written informed consent was obtained from 27 patients (10 females and 17 males; mean age 44 years, age range 21-83 years) with either upper or lower extremity fractures, and with metal hardware, who underwent CBCT scans and had a clinical radiograph of the affected part. Images were assessed by two independent observers for quality and interobserver reliability for seven visualization tasks. Visual grading characteristic (VGC) curve analysis determined the differences in image quality between CBCT and plain radiography. Interobserver agreement was calculated using Pearson's correlation coefficient.
  
  
  RESULTS
  VGC results displayed preference of CBCT images to plain radiographs in terms of visualizing (1) cortical and (2) trabecular bones; (3) fracture line; (4) callus formation; (5) bridging ossification; and (6) screw thread-bone interface and its inferiority to plain radiograph in the visualization of (7) large metallic side plate contour with strong interobserver correlation (p-value < 0.05), except for visualizing large metallic side plate contour.
  
  
  CONCLUSIONS
  For evaluation of fracture healing in the presence of metal hardware, CBCT image quality is preferable to plain radiograph for all visualization tasks, except for large metallic side plate contours. Advances in knowledge: CBCT has the potential to be a good diagnostic alternative to plain radiographs in evaluation of fracture healing in the presence of metal hardware.
authors.affiliation: 1 Department of Orthopedics, Johns Hopkins Hospital, Baltimore, MD, USA.
authors.forename: Greg M
authors.initials: GM
authors.lastname: Osgood
authors.affiliation: 2 Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
authors.forename: Gaurav K
authors.initials: GK
authors.lastname: Thawait
authors.affiliation: 2 Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
authors.forename: Nima
authors.initials: N
authors.lastname: Hafezi-Nejad
authors.affiliation: 2 Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
authors.forename: Delaram
authors.initials: D
authors.lastname: Shakoor
authors.affiliation: 1 Department of Orthopedics, Johns Hopkins Hospital, Baltimore, MD, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Shaner
authors.affiliation: 3 Carestream Health Inc., Rochester, NY, USA.
authors.forename: John
authors.initials: J
authors.lastname: Yorkston
authors.affiliation: 4 Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Wojciech B
authors.initials: WB
authors.lastname: Zbijewski
authors.affiliation: 4 Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Siewerdsen
authors.affiliation: 2 Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
authors.forename: Shadpour
authors.initials: S
authors.lastname: Demehri
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054893:Cone-Beam Computed Tomography / Q000592:standards* / Q000706:statistics & numerical data; D005121:Extremities; D005260:Female; D050723:Fractures, Bone / Q000000981:diagnostic imaging*; D006801:Humans; D016268:Internal Fixators; D008297:Male; D008670:Metals; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D008670:Metals