Department of Radiography, College of Health Sciences, Bayero University Kano, Nigeria.
Department of Radiography, College of Health Sciences, Bayero University Kano, Nigeria.
J Med Imaging Radiat Sci. 2021 Sep;52(3):435-442. doi: 10.1016/j.jmir.2021.03.035. Epub 2021 Apr 22.
Mammography involves the use of low energy X-rays to image the breast tissue. Although low dose radiation is used, the use of ionising radiation implies the risk of inducing breast cancer. Thus, the study established local DRLs for digital mammography for in-house dose optimisation.
This was a retrospective study that had a total of 240 women that presented for mammography at the two tertiary institutions located in the Northwest region of Nigeria. Patient demographic information including compressed breast thickness (CBT), which is the breast tissue thickness across the imaging plate, and mean glandular dose (MGD) were recorded. Data were analysed based on descriptive and inferential statistics using SPSS statistical software. The DRLs based on MGD and CBT were established and compared with the relevant data in the literature.
Local DRLs based on MGD and CBT were established at the 75th percentile (craniocaudal (CC): 1.50 mGy; 57 mm; mediolateral (MLO): 1.60 mGy; 63 mm) and 95th percentile (CC: 3.74 mGy; 69 mm; MLO: 3.61 mGy; 76 mm). The MGD based on manual exposure was significantly (p < 0.005) higher compared to the automatic optimisation parameter (AOP) mode which suggests the need to continuously adhere to the use of AOP mode for in-house dose optimisation.
The study established local DRLs for the digital mammography systems at the 75th and 95th percentiles which compared well with the values established in the literature. Manual selection of parameters should only be employed where there are legitimate indications as it is associated with high exposure. Also, manual selection of parameters should be based on preset tables as a function of compressed breast thickness.
乳腺 X 线摄影术使用低能量 X 射线对乳腺组织进行成像。尽管使用的是低剂量辐射，但电离辐射的使用意味着诱发乳腺癌的风险。因此，该研究为内部剂量优化建立了数字乳腺摄影术的局部剂量参考水平。
这是一项回顾性研究，共有 240 名女性在尼日利亚西北部的两个三级机构进行乳腺 X 线摄影术。记录患者的人口统计学信息，包括压缩乳腺厚度（CBT），即穿过成像板的乳腺组织厚度，以及平均腺体剂量（MGD）。使用 SPSS 统计软件对数据进行描述性和推断性统计分析。根据 MGD 和 CBT 建立了局部剂量参考水平，并与文献中的相关数据进行了比较。
根据 MGD 和 CBT 建立了局部剂量参考水平，分别在第 75 百分位数（头尾位（CC）：1.50 mGy；57 mm；内外斜位（MLO）：1.60 mGy；63 mm）和第 95 百分位数（CC：3.74 mGy；69 mm；MLO：3.61 mGy；76 mm）。手动曝光的 MGD 明显（p<0.005）高于自动优化参数（AOP）模式，这表明需要不断坚持使用 AOP 模式进行内部剂量优化。
该研究在第 75 百分位数和第 95 百分位数为数字乳腺摄影系统建立了局部剂量参考水平，与文献中建立的水平相比，这些水平相当。只有在有合理指示的情况下才应手动选择参数，因为这与高剂量暴露有关。此外，手动选择参数应根据压缩乳腺厚度的预设表格进行。
