title: Radiation exposure from pediatric head CT: a bi-institutional study.
abstract: BACKGROUND
  Medical radiation from CT should be kept as low as reasonably achievable (ALARA), particularly in young patients.
  
  
  OBJECTIVE
  To examine radiation dose from head CT in children in a trauma center (TC) and a regional children's hospital (RCH).
  
  
  METHODS
  A random sample of 240 children (0-3, 4-9, 10-14 years of age) from the TC were compared with a similar cohort from the RCH. All children had undergone at least one head CT scan without contrast enhancement; data from PACS and Department of Radiology Information System were used to estimate normalized effective dose (ED). Lifetime attributable risk of cancer incidence was estimated using the Biologic Effects of Ionizing Radiation (BEIR) VII report.
  
  
  RESULTS
  The mean normalized ED was significantly higher in the youngest children at the TC (2.74 mSv in those aged 0-3 years vs. 2.23 mSv in those aged 10-14 years; P<0.001) and at the RCH (2.44 mSv in those aged 0-3 years vs. 1.71 mSv in those aged 10-14 years; P<0.001). Each decreasing year of age was independently associated with a 0.06 mSv higher mean normalized ED (P<0.001). After adjusting for the age difference between the institutions, the mean normalized ED was 0.44 mSv lower at the RCH than at the TC across all ages (95% CI 0.31-0.58, P<0.001). A higher lifetime attributable risk of cancer was associated with younger age.
  
  
  CONCLUSIONS
  The radiation dose from head CT in children as defined by the normalized ED was highest in the youngest children and varied significantly between institutions in this bi-institutional study.
authors: Department of Pediatrics, Harborview Medical Center, University of Washington, Seattle, WA 98104, USA.
authors: Mary A
authors: MA
authors: King
authors: Kalpana M
authors: KM
authors: Kanal
authors: Annemarie
authors: A
authors: Relyea-Chew
authors: Mark
authors: M
authors: Bittles
authors: Monica S
authors: MS
authors: Vavilala
authors: William
authors: W
authors: Hollingworth
mesh_terms: D000293:Adolescent; D001822:Body Burden; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005260:Female; D006257:Head / Q000000981:diagnostic imaging*; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D016016:Proportional Hazards Models; D011874:Radiometry / Q000706:statistics & numerical data*; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*; D014481:United States / Q000453:epidemiology