title: Shift in imaging modalities of the urinary tract over a 25-year period and its impact on ionizing radiation doses given to patients.
abstract: OBJECTIVE
  To explore the shift in imaging modalities used when examining the urinary tract over the period 1979-2003 and to see how this shift, together with a radiation protection policy, have influenced the doses of ionizing radiation used.
  
  
  METHODS
  Activity reports from a department of radiology were reviewed. Relevant radiation dose estimates were obtained from the Norwegian Radiation Protection Authority.
  
  
  RESULTS
  Ultrasound (US) was introduced in 1983 and has been increasingly used since then. MRI was introduced in 1992 and has been used to some extent when examining the urinary tract. The use of i.v. pyelography decreased by 50% during the review period and the use of plain radiographs remained practically unchanged. The number of CT examinations increased until 1983, but decreased thereafter. The total number of examinations of the urinary tract has increased during the review period, but the radiation doses given have decreased.
  
  
  CONCLUSIONS
  The introduction of US and MRI, together with a radiation protection policy, have reduced the ionizing radiation doses given to this population, in spite of an increase in the total number of examinations of the urinary tract.
authors: Department of Radiology, Hospital of Buskerud, Drammen, Norway. lars.borgen@sb-hf.no
authors: Lars
authors: L
authors: Borgen
authors: Harald
authors: H
authors: Ostensen
authors: Tor Erik
authors: TE
authors: Gudmundsen
authors: Erling
authors: E
authors: Stranden
authors: Hilde Marie
authors: HM
authors: Olerud
mesh_terms: D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data / Q000639:trends*; D011879:Radiotherapy Dosage; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data / Q000639:trends*; D014463:Ultrasonography; D014570:Urologic Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging