The change of radiation doses to the patient when switching from conventional technique to digital technique without films in barium enema and IVU examinations. Final report SSI research project P933

X-ray examinations of the colon (barium enema) and the kidneys (IVU) are combined with rather high radiation doses to the patients when using analogue technique with film-screen systems. It is therefore of great interest to see if the change from analogue to digital technique involves a reduction of doses. Barium enema and IVU examinations were monitored with DAP-meters before and after the X-ray department changed to digital techniques. For IVU also the change from storage phosphor plates to a Direct Digital detector is included. The study comprises between 53 and 87 patients for each modality of the two examinations. A considerable dose reduction was observed. In barium enema the overview images with large field sizes were omitted when using digital technique. On the other hand the number of spot images was increased from 6 to 22. The fluoroscopy time was increased from 4 minutes to 6 minutes. The DAP value was reduced from 54,3 Gy cm sup 2 to 21,9 Gy cm sup 2. For IVU a dose reduction from 44,5 Gy cm sup 2 to 32,5 Gy cm sup 2 was achieved in the first step when storage phosphor plates replaced the film-screen system. In the next step one exposure was omitted and the storage phosphor plates were replaced with a flat panel detector. This step resulted in a dose reduction from 32,5 Gy cm sup 2 to 12,5 Gy cm sup 2. The main dose reduction in barium enema was a result of omitting the overview images and the use of pulsed fluoroscopy. In IVU the introduction of the flat panel detector was the main reason for the dose reduction