The effect of phosphor persistence on image quality in digital x-ray scanning systems

摘要: A digital x-ray scanning system offers several advantages over conventional film–screen systems. However, there are sources of image degradation resulting from the motion, such as motion blur due to temporal response phosphor. This mechanism produces an asymmetrical blur, requiring use complex optical transfer function (OTF) rather than normal modulation function(MTF) for correct characterization resolution. The luminescence eight phosphors was measured under pulsed excitation. weighted exponential model used represent primary luminescence. dominant lifetimes ranged 2.7 μs Gd 2 O S:Pr 558 S:Tb . long term also measured, monitoring significant increases in a slow form known afterglow. Afterglow modeled by inverse power law equation. found be strong two studied (ZnCdS:Ag and YTaO 4 ). In selecting phosphor system, it must satisfy criteria, including fast response. Thus, like , which has luminescence, but otherwise excellent imaging properties, may not useful more rapid CsI:Tl.