Comparison of low-contrast detail perception on storage phosphor radiographs and digital flat panel detector images

A contrast detail analysis was performed to compare perception of low-contr ast details on X-ray images derived from digital storage phosphor radiograp hy and from a nat panel detector system based on a cesium iodide/amorphous silicon matrix. The CDRAD 2.0 phantom was used to perform a comparative contrast detail ana lysis of a clinical storage phosphor radiography system and an indirect typ e digital nat panel detector unit. Images were acquired at exposure levels comparable to film speeds of 50/100/200/400 and 800. Four observers evaluat ed a total of 50 films with respect to the threshold contrast for each deta il size. The numbers of correctly identified objects were determined for al l image subsets. The overall results show that low-contrast detail perception with digital f lat panel detector images is better than with state of the art storage phos phor screens, This is especially true for the low-exposure setting, where a nearly 10% higher correct observation ratio is reached. Given its high det ective quantum efficiency the digital flat panel technology based on the ce sium iodide scintillator/amorphous silicon matrix is best suited for detect ion of low-contrast detail structures, which shows its high potential for c linical imaging.