108 Z . Tahiri et al .: Radioprotection 2024 , 59 ( 2 ), 104 – 110
Table 6 . Statistical representation of the exposure parameters collected in this study .
Projection |
Tube voltage ( kVp ) |
Tube current ( mAs ) |
MGD ( mGy ) |
Compressed Breast thickness ( mm ) |
Compressive force ( daN ) |
Median Median Median Median Median
CC |
28,5 ± 1.8 |
78 ± 22 |
1.34 ± 0,36 |
55.92 ± 2,38 |
10.8 ± 2 |
MLO |
29 ± 1.5 |
86 ± 16 |
1,48 ± 0,38 |
56.62 ± 0,77 |
12.9 ± 3 |
Table 7 . Comparison of the MGD values estimated in this study to selected published values .
Country |
MGD ( mGy ) |
|
CC |
MLO |
Greece ( Lekatou et al ., 2019 ) |
1.13 |
1.30 |
United Kingdom ( Young et al ., 2016 ) |
1.58 |
1.79 |
Portugal ( Sá dos Reis et al ., 2018 ) |
1.85 |
2.10 |
Qatar ( Al Naemi et al ., 2020 ) |
2.22 |
2.5 |
Iran ( Aliasgharzadeh et al ., 2021 ) |
2.51 |
2.95 |
This study |
1.34 |
1.48 |
4 Discussion
Our study shows that the median MGD per CC incidence was always lower than that of the corresponding MLO incidence . This result can be explained by the difference in the thickness of the compressed breast ( with a median of 55.92 mm for the CC incidence and 56.62 mm for the MLO incidence ) and the inclusion of denser parts such as the pectoral muscle in the MLO incidence , which may result in an increase in exposure . The presence of the pectoralis muscle in the MLO incidence is also responsible for the higher compression force ( 12.9 daN for MLO and 10.8 daN for CC ).
Regarding the relationship between MGD and breast thickness , the median MGD increases with thickness for all units included in the study . Unit 5 had a significantly lower dose than the other units and the highest doses were recorded in unit 2 .
The results of this study can be compared with the results of similar surveys conducted in different countries . Published results from a Malaysian study involving 300 women show that the DMG and compressed thickness were 1.54 mGy and 37 mm for CC incidence and 1.82 mGy and 44 mm for MLO ( Jamal et al ., 2003 ). A British study reviews a large representative sample of dose measurements collected in the screening program . The MGD was 2.23 mGy for the MLO incidence and 1.96 mGy for the CC incidence , and the median compressed breast thicknesses were 54.3 mm and 51.5 mm for the two incidences , respectively ( Young et al ., 2005 ). On the other hand , the MGD found in a British study was 1.6 mGy for CC and 1.93 for MLO . Belgian researchers presented the results of an audit of 27 centers where the MGD was 1.76 mGy ( Smans et al ., 2005 ).
Table 7 shows the comparison between the MGD values measured in this study and some published values from other studies for mammography .
The median MGD values from this study for craniocaudal ( CC ) and mediolateral oblique ( MLO ) views , at 1.34 mGy and 1.48 mGy , respectively , were compared with data from studies conducted in Greece , the United Kingdom , Portugal , Qatar , and Iran . In comparison , the CC MGD in this study is lower than values reported in Qatar ( 2.22 mGy ) and Iran ( 2.51 mGy ), and similar to or lower than Greece ( 1.13 mGy ), the United Kingdom ( 1.58 mGy ), and Portugal ( 1.85 mGy ). For MLO views , the MGD values in this study are again lower than those reported in Qatar ( 2.5 mGy ) and Iran ( 2.95 mGy ) and fall within or below the range observed in Greece ( 1.30 mGy ), the United Kingdom ( 1.79 mGy ), and Portugal ( 2.10 mGy ). These findings suggest that the MGD values in this study are generally comparable to or lower than international benchmarks , indicating a potentially well-optimized exposure mammography protocol , but it is noteworthy that balancing radiation exposure and diagnostic image quality is of a paramount importance . It ’ s important to consider variations in imaging protocols , patient populations , and equipment characteristics when interpreting and comparing these results .
Many factors can affect the radiation dose to the breast during screening mammography , with the anode / filter combination being one of the key variables . As previously mentioned , we considered four different target / filter combinations in this study : Rh / Rh , Mo / Mo , Mo / Rh , and Rh / Mo . It is important to note that the number of machines with various anode / filter combinations included in this study may introduce uncertainties when drawing definitive conclusions from the results , especially given that only two combinations were the most commonly used .
While our findings indicated that , in general , the Rh / Rh anode / filter combination tended to yield the lowest radiation dose to breast tissue for different incidences , we acknowledge that this observation is subject to variation based on other factors . Compressed breast thickness and density , for instance , may significantly influence the performance of different anode / filter combinations .
We recognize the need for further investigation into the interplay between anode / filter combinations , breast characteristics , and image quality . In our study , we primarily focused on dose assessments , and while our findings provide valuable insights into radiation exposure , future research is required to comprehensively evaluate the relationship between anode / filter combinations and image quality under varying breast conditions . This more detailed analysis will help in providing a more comprehensive understanding of the complexities involved in optimizing radiation dose during mammography .
In conducting this analysis , it is paramount to acknowledge the influence of breast thickness and image quality on the selection of anode / filter combinations by the mammography machines under study . The data reveals that the Rh / Rh