[An improved method for determining the mean parenchyma dose in mammography].
In mammography, it is currently assumed that the mean dose to glandular tissue DG is relevant to characterize the risk of carcinogenesis. The mean glandular dose DG results from the measured air kerma Ka at the location of the entrance surface of the breast multiplied by the conversion factors g, which usually are calculated with the help of Monte-Carlo-Simulations and which are mostly given for a standard composition of tissue (50% glandular/50% adipose tissue). By means of the signals of the double-detector of the automatic-exposure-control of the mammographic device, it is possible to obtain information about the mean composition of the breast-tissue. The knowledge of this composition enables a better calculation of the mean glandular dose DG by using conversion factors that are adapted to the tissue. This method was applied to a total of 1020 women. The comparison with the evaluation by using the conventional method shows, on average, deviations in the mean glandular dose of 9%, in specific cases the differences can be as much as 35%.
Klein
R
R
Institut für Medizinische Physik Friedrich-Alexander-Universität, Erlangen.
Aichinger
H
H
Joite-Barfuss
S
S
Säbel
M
M
Schulz-Wendtland
R
R
D001940:Breast / Q000528:radiation effects*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000517:prevention & control; D005260:Female; D006801:Humans; D008327:Mammography / Q000295:instrumentation*; D008953:Models, Anatomic; D009010:Monte Carlo Method; D009381:Neoplasms, Radiation-Induced / Q000000981:diagnostic imaging / Q000517:prevention & control; D011874:Radiometry / Q000295:instrumentation*; D012307:Risk Factors; D014963:X-Ray Intensifying Screens
Eine verbesserte Methode zur Bestimmung der mittleren Parenchymdosis bei der Mammographie.