Comparison of performance characteristics of conventional and K-edge filters in general diagnostic radiology

Abstract

The performance characteristics of conventional and K-edge filters have been studied for the entire field of general diagnostic radiology. The problem of optimising the conflicting needs from patient dose, image contrast and exposure time was managed primarily by computer simulation. In comparison to conventional filters like iron or copper no significant advantages can be obtained with K-edge filters in practice except for the special circumstances of automatic fluoroscopy. The optimal choice of conventional filters is discussed. The different roles of backscattered radiation for skin dose and integral dose are demonstrated, and the necessity of correcting for increased backscatter following additional filtration is stressed. The potential for dose reductions by adding filtration has been found to be substantially smaller than the figures mostly reported. Finally some methodological problems of studies of this kind are pointed out.