X-Ray Image Intensifier Tubes Using Rare Earth Oxysulfide Phosphors

Inproved utilization of incident x-ray quanta in medical x-ray image intensifier tubes will allow operation at reduced x-ray dose levels and/or yield pictures with higher signal-to-noise ratio. This paper describes the characteristics and performances of experimental screens and image intensifier tubes using La2O2S(Tb) and Gd2O2S(Tb) phosphors. Inproved quantum utilization by a factor of 2 to 3 is observed relative to screens and image intensifier tubes made with conventional ZnCdS(Ag) phosphors. Accordingly, reduction of patient and operator dosage by a factor of 2 to 3 is found to be possible.