A STUDY OF DOSE REDUCTION USING DIGITAL LUMINESCENCE RADIOGRAPHY FOR LATERAL SKULL RADIOGRAPHY

For lateral skull radiography the minimum required radiation patient e xposure to ensure adequate image quality was determined for digital lu minescence radiography (DLR) in comparison with a screen-film system ( speed class 200). Radiographs were produced with a grid technique on c onventional X-ray equipment. A real prepared female head including a t rue fracture above the pars petrosa ossis temporalis was imaged. The t ube current-time product (mAs), and thus the surface entrance dose, wa s varied systematically. Surface entrance dose was measured with TLD-1 00 rods. Image quality was judged by experienced radiologists accordin g to the criteria: visual resolution, mean optical density, contrast a nd perceptibility of specific bone structures. Surface entrance dose w as reduced from 0.46 to 0.20 mGy by application of DLR instead of spee d class 200 screen-film system without loss of diagnostic information in clinical routine. This corresponds to a dose reduction potential of 57% showing a good agreement with the dose reduction potential of 52% obtained in a previous study using the Alderson head phantom.