title: Decreasing the effective radiation dose in pediatric craniofacial CT by changing head position.
abstract: BACKGROUND
  Children are exposed to ionizing radiation during pre- and post-operative evaluation for craniofacial surgery.
  
  
  OBJECTIVE
  The primary purpose of the study was to decrease effective radiation dose while preserving the diagnostic quality of the study.
  
  
  METHODS
  In this prospective study 49 children were positioned during craniofacial CT (CFCT) imaging with their neck fully extended into an exaggerated sniff position, parallel to the CT gantry, to eliminate the majority of the cervical spine and the thyroid gland from radiation exposure. Image-quality and effective radiation dose comparisons were made retrospectively in age-matched controls (n = 49).
  
  
  RESULTS
  When compared to CT scans reviewed retrospectively, the prospective examinations showed a statistically significant decrease in z-axis length by 16% (P < 0.0001) and delivered a reduced effective radiation dose by 18% (P < 0.0001). The subjective diagnostic quality of the exams performed in the prospective arm was maintained despite a slight decrease in the quality of the brain windows. There was statistically significant improvement in the quality of the bone windows and three-dimensional reconstructed images.
  
  
  CONCLUSIONS
  Altering the position of the head by extending the neck during pediatric craniofacial CT imaging statistically reduces the effective radiation dose while maintaining the diagnostic quality of the images.
authors.affiliation: School of Medicine, Oregon Health and Science University, Portland, OR 97239, USA.
authors.forename: Ryne A
authors.initials: RA
authors.lastname: Didier
authors.forename: Anna A
authors.initials: AA
authors.lastname: Kuang
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Schwartz
authors.forename: Nathan R
authors.initials: NR
authors.lastname: Selden
authors.forename: Donna M
authors.initials: DM
authors.lastname: Stevens
authors.forename: Dianna M E
authors.initials: DM
authors.lastname: Bardo
mesh_terms: D001822:Body Burden; D019465:Craniofacial Abnormalities / Q000000981:diagnostic imaging*; D005260:Female; D006257:Head; D006801:Humans; D007223:Infant; D008297:Male; D011187:Posture; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods*; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*