An investigation into the radiation dose associated with different imaging systems for chest radiology

With the advent of digital imaging there now exists a range of imaging techniques which may be used to acquire chest images. The purpose of this investigation was to determine typical radiation doses associated with the use of a conventional film-screen system, 100 mm film technique, large-field digital image intensifier radiography, computed radiography and a scanning slit system (AMBER, Oldeft, Netherlands). Radiation doses to relevant organs were assessed using direct measurements made with lithium fluoride thermoluminescent dosemeters, together with calculations made using normalized dose data. Typical doses were assessed using anthropomorphic phantoms for both postero-anterior and lateral projections. The risk-related quantities, i.e. effective dose and effective dose equivalent, were then calculated from these organ doses. When compared on the basis of effective dose equivalent, certain imaging techniques were seen to offer the potential for significant dose reduction, possibly at the expense of image quality.