Radiation doses and image information in digital pelvimetry with a phosphorous screen

Purpose: The aim of the investigation was to determine the patient dose in digital pelvimetry by means of a phosphorous screen as compared to a screen-film combination of very high sensitivity.Material and Methods: Entrance dose measurements and absorbed dose determinations in a series of patient exposures were made. In the first series the exposure reduction was achieved by reducing the mAs (tube current × exposure time) for the lateral and the a.p. views as compared with those used for the screen-film system. In the second series the tube potential, kV, was increased for both projections in order to increase the penetration capacity of the radiation.Results and Conclusion: The imaging plate technique can be used in pelvimetry with a dose reduction (and a corresponding reduction of the radiation risk to the foetus) to less than 50% of that achieved with a screen-film system of the very highest sensitivity.