RADIATION-DOSE REDUCTION IN DIAGNOSTIC-X-RAY PROCEDURES

The performance of K-edge filters to modify the x-ray spectrum is investigated experimentally in a variety of clinical situations involving bone/soft tissue imaging, with the aim of improving the optimization between image contrast and patient exposure. The results show that simultaneous improvement of contrast and reduction of exposure is possible for a wide range of patient sizes. For conditions of fixed contrast skin exposure reductions of better than 50% and integrated dose reductions of up to 30% have been achieved with tolerable increases in tube load. Rare earth salt solutions were used as an inexpensive alternative source of K-edge filtration, and their performance was found to be in no way inferior to that of expensive metal foils.