ABSTRACT
Objective:To compare radiation dose between digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM), and explore the correlation of average glandular dose(AGD) with breast density and compression thickness.Methods:The mammographic data of patients with breast diseases who underwent digital breast tomosynthesis (DBT) and the population who underwent full-field digital mammography (FFDM) screening in the First Affiliated Hospital of Kunming Medical University from October 2020 to May 2022 were retrospectively collected. The compression thickness, compression force and AGD were recorded. According to the 2013 ACR BI-RADS MAMMOGRAPHY, the breast gland density was classified into 4 types: a(glandular tissue<25%), b(glandular tissue 25%~50%), c(glandular tissue 50%~75%) and d(glandular tissue >75%), by two senior doctors engaged in breast imaging diagnosis. The relationships between different gland densities, different compression thicknesses and AGD under FFDM and DBT mode were analyzed.Results:In both FFDM and DBT modes, the AGD increased significantly with the increase of breast density( F=861.63, 617.83, 330.33, 451.45, 290.47, P<0.001), and AGD a<AGD b<AGD c<AGD d. For type c and d breasts undergoing FFDM, AGD was lowest when the compression thickness was 31~40 mm. Under the same compression thickness, The AGD DBT was significantly higher than the AGD FFDMin all types (Type a: t=-17.88, -42.19, -29.90, -28.14, -24.95, P<0.001; Type b: t=-49.18, -35.94, -27.25, -28.37, -24.10, P<0.001; Type c: t=-11.78, -32.90, -23.13, -20.51, -18.24, P<0.001; Type d: t=-7.94, -26.24, -17.24, -15.44, -13.81, P<0.001). The difference between two AGDs of Type d with compression thickness of 61~70 mm was the largest, which was 1.07 mGy (95% CI: 0.92~1.22). The AGD was positively correlated with breast density and compression thickness, and the relationship of FFDM was stronger than that of DBT. Conclusions:The AGD is positively correlated with breast density and compression thickness in mammography. Compared with FFDM, DBT can increase AGD, The AGD would increase in DBT than FFDM but be safe. DBT would be beneficial to patients with breast diseases in clinical practice.
ABSTRACT
Objective To investigate the average glandular dose of digital mammography in Zigong, China, and to explore the methods of reducing average glandular dose. Methods A total of 260 patients who underwent digital mammography at six hospitals located in Zigong during the year 2022 were included in this study. Their personal information, photography position, breast compression thickness, exposure parameters, and average glandular dose were collected. Analysis of variance and correlation analysis were performed for data analysis. Results Among the 260 patients who underwent digital mammography, the average breast compression thickness was 46.3 mm and the average glandular dose was 1.70 mGy. There was a significant difference in average glandular dose between patients with different breast compression thickness(P <0.05), and average glandular dose was positively correlated with breast compression thickness. There were no significant differences in average glandular dose between patients with different photography positions and patients with different ages (P>0.05). Conclusion The average glandular dose of patients undergoing digital mammography is at an acceptable level in Zigong. The average glandular dose is impacted by the breast compression thickness, target/filter, and exposure parameters. These factors should be optimized to reduce glandular dose during digital mammography.
ABSTRACT
Objective:To compare and analyze the relationship between average glandular dose (AGD) and breast density and compression thickness in digital breast tomosynthesis(DBT)/full-field digital mammography(FFDM), and to explore the optimal selection and application of imaging parameters for different types of breast (thickness and density) in specific situations.Methods:The clinical data of 229 cases of breast Combo (DBT+ FFDM) were retrospectively analyzed. The compression thickness, AGD, kVp and type of quantified breast density (Q_abd) of CC and MLO view were collected respectively. The relationship between the AGD and the breast compression thickness and Q_abd density classification was analyzed.Results:There was a positive correlation between AGD and compression thickness (CC: r =0.55, 0.53, P< 0.001; MLO: r =0.62, 0.48, P< 0.001) and breast density(CC: r =0.36, 0.39, P< 0.001; MLO: r =0.16, 0.30, P < 0.001) in DBT/FFDM. The difference between groups for AGD was little in CC of DBT, but significant in CC of FFDM(groups by thickness, CC: F =35.29, 31.32, P<0.005; MLO: F =44.83, 27.02, P<0.005; groups by Q_abd, CC: F =18.68, 19.76, P<0.005, MLO: F=4.58, 10.52, P<0.005); the breast Q_abd was inversely proportion to the mean compression thickness (CC: F =16.28, P<0.005; MLO: F =17.81, P<0.005). At the same time, the interaction effect on AGD between the breast density and thickness was considered, and only for the MLO in FFDM mode they had an interaction on AGD ( F =3.16, P =0.005). Conclusions:The cumulative dose of DBT and FFDM may increase the radiation risk. Single-view CC/MLO-DBT or CC/MLO-(DBT+ FFDM)+ single-view MLO/CC-FFDM mode is preferred for mammography, which plays a positive role in radiation risk reduction.