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IMAGE QUALITY AND PROCESSING TECHNIQUES

Real-time radiography is generally less sensitive than film radiography. A number of factors contribute to this difference. These factors include (1) the difference in size between the silver halide grains of film and the cesium iodide needles of the RTR scintillation screen, (2) the phosphor bloom of the fluorescent screen, (3) the random pixel noise inherent in image intensifiers, and (4) the pincushion image distortion also inherent in these systems.

Real-time radiography systems using an image intensifier tube have poorer resolution (2-4 line pairs per millimeter) [LP/mm] than film (10-20 LP/mm) does. Phosphor bloom, especially in the output conversion phosphor, is the principle cause of diminished resolution.