[Multislice CT in a diagnostic imaging department: radiation doses delivered in 1 year.]

To determine the usage of CT in our diagnostic imaging department and the dose of radiation CT delivered to patients.

We carried out two studies, a retrospective study on the administrative data from one year and a prospective study over one month, to determine the amount of activity of the two multislice CT scanners in our department. We recorded the total number of examinations, the different types of examination performed, and the age distributions of the patients examined. We used these data and the results of dosimetric measurements to estimate the typical radiation dose for each type of examination, its contribution to the collective radiation dose, and the total collective radiation dose from CT examinations at our hospital.

The retrospective study found that 15038 examinations were performed in 12678 patients in one year. The most common CT examinations were cranial (38.2%), abdomen-pelvis (17.5%), chest-abdomen (11.7%), chest (9.3%), and lumbar-sacral spine (6.8%). Some protocols used doses of radiation that were higher than those recommended by European experts. The total collective dose of radiation delivered to patients at our hospital by CT was estimated at 70 person.Sv. Abdomen-pelvis examinations contributed 31% of the total dose.

This study has provided detailed knowledge about the use of CT in our diagnostic imaging department, about the dose of radiation delivered, and about possibilities for improving the use of our CT scanners.