| dc.description.abstract | Mammography is a specialized medical imaging technique that uses low-energy Xrays
to diagnose and screen the human breast. Average glandular dose (AGD)
estimates the average dose absorbed by the glandular tissues of a breast during a
mammographic examination. Nowadays, the glandular tissues are considered the
breast tissue type which is at high risk for radiation during a mammographic
examination. Therefore, the AGD is widely recommended and accepted by several
bodies including International Commission on Radiological Protection (ICRP) as the
most suitable dosimetric quantity to determine the risk of carcinogenesis induced
by radiation. Digital breast tomosynthesis (DBT) is a modern technology that can
help radiologists to improve their ability to detect breast cancer. AGD displayed by
the mammography system and AGD calculated by the method suggested by Dance
et al. in 2011 for women, were compared in the present study. The study was
performed on 140 patients who underwent DBT examination. The AGD,
compression breast thickness (CBT), half-value layer (HVL), kVp, mAs, and
target/filter combination were obtained from the machine, and AGD for each
radiograph taken for each patient was calculated using the equation proposed by
Dance et al. 2011. The data were analysed using statistical tests such as the Shapiro-
Wilk test, Spearman’s test, and Sign test with P<0.05 indicating a level of
significance. The results showed that the displayed median AGDs were 1.34 mGy
and 1.33 mGy for right and left breasts respectively and calculated median AGDs
were 1.28 mGy and 1.24 mGy for right and left breasts respectively. In conclusion,
the displayed AGD is statistically significantly higher than the calculated AGD of both
breasts (p<0.05). The result of the present study highlights the importance of
validating AGD values in radiation dosimetry of DBT examinations. | en_US |
