Optimisation of dose per image in digital imaging.

Three current digital radiography modalities are briefly described: digital fluorography, storage phosphor radiography and amorphous selenium radiography. For all of these modalities, the dose used to form an image can be varied considerably. Threshold contrast detail techniques were used to investigate the consequence of changing dose per image at the image receptor. At low doses, contrast resolution is limited by X ray quantum noise while system noise limits contrast resolution at high dose per image values.