title: Exposure of the Swiss population to computed tomography.
abstract: BACKGROUND
  The frequency of CT procedures has registered a significant increase over the last decade, which led at the international level to an increasing concern on the radiological risk associated with the use of CT especially in paediatrics. This work aimed at investigating the use of computed tomography in Switzerland, following the evolution of CT frequency and dose data over a decade and comparing it to data reported in other countries.
  
  
  METHODS
  The frequency and dose data related to CT are obtained by means of a nationwide survey. National frequencies were established by projecting the collected data, using the ratio of the number of CT units belonging to the respondents to the total number of CT units in the country. The effective doses per examination were collected during an auditing campaign.
  
  
  RESULTS
  In 2008 about 0.8 Million CT procedures (~100 CT examinations/1000 population) were performed in the country, leading to a collective effective dose of more than 6000 man.Sv (0.8 mSv/caput). In a decade the frequency of CT examinations averaged over the population and the associated average effective dose per caput increased by a factor of 2.2 and 2.9 respectively.
  
  
  CONCLUSIONS
  Although the contribution of CT to the total medical X-rays is 6% in terms of the frequency, it represents 68% in terms of the collective effective dose. These results are comparable to those reported in a number of countries in Europe and America with similar health level.
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland. abbas@aroua.com
authors.forename: Abbas
authors.initials: A
authors.lastname: Aroua
authors.forename: Eleni-Theano
authors.initials: ET
authors.lastname: Samara
authors.forename: François O
authors.initials: FO
authors.lastname: Bochud
authors.forename: Reto
authors.initials: R
authors.lastname: Meuli
authors.forename: Francis R
authors.initials: FR
authors.lastname: Verdun
mesh_terms: D001822:Body Burden; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D006801:Humans; D011829:Radiation Dosage; D011874:Radiometry / Q000706:statistics & numerical data*; D018570:Risk Assessment; D013557:Switzerland / Q000453:epidemiology; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*
references.citation: Med Phys. 2002 Oct;29(10):2247-59
references.pmid: 12408298
references.citation: Ann ICRP. 2007;37(2-4):1-332
references.pmid: 18082557
references.citation: Health Phys. 2007 May;92(5):442-8
references.pmid: 17429302
references.citation: Health Phys. 2002 Jul;83(1):46-55
references.pmid: 12075683
references.citation: Ann ICRP. 1991;21(1-3):1-201
references.pmid: 2053748
references.citation: Radiat Prot Dosimetry. 2010 Dec;142(2-4):244-54
references.pmid: 20926508
references.citation: Rev Environ Health. 2010 Jan-Mar;25(1):63-8
references.pmid: 20429161