The development of simplified calculation method for average glandular dose in mammography

• Main Authors: Yu-Ting Chao, 趙俞婷
• Other Authors: Shang-Lung Dong
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/8g6hmp

碩士 === 中山醫學大學 === 醫學影像暨放射科學系碩士班 === 106 === Introduction Estimation of average glandular dose (AGD) is an important issue in mammography. The AGD calculation method is complicate due to the fact that the compressed breast thickness (CBT) and percentage glandular content (PGC) have to be known. The purpose of this study is to develop the simplified AGD calculation method using equivalent thickness breast model (ET-BM). Material and methods The first step in this study is the development of simplified AGD calculation method using ET-BM. The second step is the verification of the ET-BM AGD calculation method using rigid phantoms with different thicknesses (2~6 cm) and compositions (PGC=0~100%). The third step is the estimation of the AGD of different compressible breast phantoms with the ET-BM AGD calculation method in Full field digital mammography (FFDM) procedure. The last step is the estimation of the AGD of different compressible breast phantoms with the ET-BM AGD calculation method in Digital breast tomosynthesis (DBT) procedure. Results Results from this study show that the error of AGD of rigid phantoms calculated using the ET-BM AGD calculation method ranging from -0.07~0.25 mGy. The values of root-mean-square errors (RMSE) on AGD for different compressible breast phantoms are 0.03~0.07 mGy in different FFDM systems. The value of RMSE on AGD for different compressible breast phantoms is 0.08 mGy in DBT procedure. Conclusion The ET-BM AGD calculation method proposed in this study can estimate AGD using imaging factors while without information about CBT and PGC in mammography. By applying the ET-BM AGD calculation method, the accuracy of AGD is acceptable in clinical practice. This method is suitable for rapidly AGD estimation in mammography.