Dose comparison between screen/film and full-field digital mammography.
The study purpose was the comparison between doses delivered by a full-field digital mammography system and a screen/film mammography unit, both using the same type of X-ray tube. Exposure parameters and breast thickness were collected for 300 screen/film (GE Senographe DMR) and 296 digital mammograms (GE Senographe 2000D). The entrance surface air kerma (ESAK) was calculated from anode/filter combination, kV(p) and mAs values and breast thickness, by simulating spectra through a program based on a catalogue of experimental X-ray spectra. The average glandular dose (AGD) was also computed. Results showed an overall reduction of average glandular dose by 27% of digital over screen/film mammography. The dose saving was about 15% for thin and thick breasts, while it was between 30% and 40% for intermediate thicknesses. Full-field digital mammography dose reduction is allowed by wider dynamic range and higher efficiency of digital detector, which can be exposed at higher energy spectra than screen/film mammography, and by the separation between acquisition and displaying processes.
Gennaro
Gisella
G
Department of Oncological and Surgical Sciences, Padua University, via Gattamelata 64, 35128, Padua, Italy. gisella.gennaro@pd.infn.it
di Maggio
Cosimo
C
D001941:Breast Diseases / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008327:Mammography; D008982:Molybdenum; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement; D012062:Relative Biological Effectiveness; D012238:Rhodium; D014131:Trace Elements; D014963:X-Ray Intensifying Screens
D014131:Trace Elements; D008982:Molybdenum; D012238:Rhodium