[Digital radiography].

Abstract

Advantages of digital radiography: Improved low contrast imaging; Image processing capability (on line or post-processing); Lower radiation dose for certain applications ("Dose variation"); Digital storage and data transfer; Only one exposure for different imaging characteristics; Optimised real-time image, "digital fluoroscopy" (DBR); Shorter examination times (DBR); Advantages for technically complicated exposures (intensive care, superpositions in the chest region, pediatry) (DLR); High dynamic range, which eliminates over or under exposure; Real time image processing and display (DBR). Disadvantages of digital radiography; Lower spatial resolution is limiting fine structure (max. theoretical resolution is 31p/mm for 1000 and app. 5 lp/mm for 2000 pixels image matrix); Spatial resolution depends from image intensifier diameter or screen format; Lower SNR (Signal to Noise Ratio) for reduced dose, increased noise impression for edge enhancement; Information losses for monitor camera (DBR) -hardcopies; Diagnostic capabilities are reduced by noise and low spatial resolution caused by certain applications (mammography).