title: A Reduction in Radiation Exposure During Pediatric Craniofacial Computed Tomography.
abstract: BACKGROUND
  Radiation exposure during computed tomography (CT) evaluation in children is the subject of growing professional and public concern. The authors previously demonstrated an 18% reduction in effective radiation dose during craniofacial CT imaging using a modified head position ("exaggerated sniff"), without any compromise of image diagnostic quality. The current study reports additional reduction of radiation exposure using a commercially available iterative reconstruction CT technique.
  
  
  METHODS
  This single-institution, retrospective cohort study compared the overall effective radiation dose received during elective pediatric craniofacial CT imaging. Patients imaged using the iterative reconstruction and exaggerated sniff protocol combined (January 2010 through December 2013) were compared with those undergoing imaging with the exaggerated sniff position alone, between October 2008 and January 2010.
  
  
  RESULTS
  A total of 325 patients who underwent CT imaging with the exaggerated sniff position, decreased dose and iterative reconstruction protocol experienced an average effective radiation dose of 1.22 mSv (47% reduction), compared with 2.32 mSv for the sniff-position alone group. Age-matched reference patients not treated using either protocol received an average of 2.82 mSv. This represents a 56.7% average radiation dose reduction for combined sniff position and iterative reconstruction patients compared with reference patients and 47.4% reduction compared with the sniff-position alone group. Image quality of both bone and brain windows was equivalent.
  
  
  CONCLUSIONS
  Altering head position and use of iterative reconstruction technique with a reduced radiation protocol diminishes CT imaging-related effective radiation dose by approximately 50% in children undergoing elective cranial CT imaging for craniofacial disorders.
authors.affiliation: *Division of Plastic and Reconstructive Surgery †Department of Surgery, Division of Pediatric Surgery ‡Department of Radiology §Department of Neurological Surgery, Oregon Health & Science University, Portland, OR.
authors.forename: Christopher
authors.initials: C
authors.lastname: Zarella
authors.forename: Ryne
authors.initials: R
authors.lastname: Didier
authors.forename: Curtis
authors.initials: C
authors.lastname: Bergquist
authors.forename: Dianna M E
authors.initials: DM
authors.lastname: Bardo
authors.forename: Nathan R
authors.initials: NR
authors.lastname: Selden
authors.forename: Anna A
authors.initials: AA
authors.lastname: Kuang
mesh_terms: D000293:Adolescent; D001921:Brain / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003398:Craniosynostoses / Q000000981:diagnostic imaging; D005145:Face / Q000000981:diagnostic imaging*; D005260:Female; D006257:Head / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000009:adverse effects* / Q000379:methods*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D056888:Patient Positioning / Q000379:methods*; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000009:adverse effects / Q000517:prevention & control*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000009:adverse effects* / Q000379:methods*