title: Radiation dose evaluation in head and neck MDCT examinations with a 6-year-old child anthropomorphic phantom.
abstract: BACKGROUND
  CT examinations of the head and neck are the most commonly performed CT studies in children, raising concern about radiation dose and their risks to children.
  
  
  OBJECTIVE
  The purpose of this study was to clarify radiation dose levels for children of 6 years of age undergoing head and neck multidetector CT (MDCT) examinations.
  
  
  METHODS
  Radiation doses were measured with small-sized silicon-photodiode dosimeters that were implanted at various tissue and organ positions within a standard 6-year-old anthropomorphic phantom. Organ and effective doses of brain CT were evaluated for 19 protocols in nine hospitals on various (2-320 detector rows) MDCT scanners.
  
  
  RESULTS
  The maximum value of mean organ dose in brain CT was 34.3 mGy for brain. Maximum values of mean doses for the radiosensitive lens and thyroid were 32.7 mGy for lens in brain CT and 17.2 mGy for thyroid in neck CT. seventy-fifth percentile of effective dose distribution in brain CT was approximately the same as the diagnostic reference level (DRL) in the 2003 UK survey.
  
  
  CONCLUSIONS
  The results of this study would encourage revision of MDCT protocols in pediatric head and neck CT examinations for dose reduction and protocol standardization.
authors.affiliation: School of Health Sciences, Nagoya University, Daikominami, Higashi-ku, Nagoya 461-8673, Japan. kawaura@met.nagoya-u.ac.jp
authors.forename: Chiyo
authors.initials: C
authors.lastname: Yamauchi-Kawaura
authors.forename: Keisuke
authors.initials: K
authors.lastname: Fujii
authors.forename: Takahiko
authors.initials: T
authors.lastname: Aoyama
authors.forename: Shuji
authors.initials: S
authors.lastname: Koyama
authors.forename: Masato
authors.initials: M
authors.lastname: Yamauchi
mesh_terms: D001822:Body Burden; D002648:Child; D005260:Female; D006257:Head / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D009333:Neck / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods*; D012062:Relative Biological Effectiveness; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods*