Shift in imaging modalities of the urinary tract over a 25-year period and its impact on ionizing radiation doses given to patients.

OBJECTIVES: 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. MATERIAL AND 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.

Shift in imaging modalities of the spine through 25 years and its impact on patient ionizing radiation doses.

STUDY DESIGN: Retrospective. OBJECTIVE: To explore the shift in modalities when diagnosing the spine in the years 1979-2003. To see how this shift, together with a radiation protective policy, have influenced on the ionizing radiation doses. SUMMARY OF BACKGROUND DATA: The shift from CT/myelography to MR when diagnosing the spine is well known. To what extent this has changed the radiation doses has to our knowledge not yet been published. METHODS: Activity reports from a department of radiology have been reviewed. Relevant radiation doses estimates have been obtained from the Norwegian Radiation Protection Authority. RESULTS: MRI was introduced in 1992 and has been used increasingly since then. Conventional X-ray to the spine has been practically unchanged. Myelography and CT decreased markedly after the introduction of MRI. The total number of examinations of the spine has increased, but the radiation doses given have decreased since 1993. CONCLUSIONS: The introduction of MRI together with a radiation protective policy have reduced the ionizing radiation doses given to this population, in spite of an increase in the total number of examinations of the spine.