[Evaluation of metal artifact in computed radiography].

We know that computed radiography (CR) has many factors to generate artifacts, such as the over / under shoot, aliasing and more. Recently, we encountered an artifact, we call a metal artifact, not attributable to any known factors in clinical images. To elucidate the cause of this artifact, we did some experiments with an in-house phantom. The experiments showed that the metal artifact was seen only when we put an object that absorbs X-rays parallel to the scanning line on imaging plate (IP). From these results, we speculated that the factor causing the afterglow is associated with photo-stimulated luminescence from IP.