Comparison of different anode filter combination with full-field digital mammography: imaging quality versus radiation dose

Abstract

Objective To compare imaging quality and radiation dose of different anode filter combination for full-field digital mammography.Methods The image of FLUKE NA 18-220 phantom were taken at full-field digital mammography (FFDM),system with Mo/Mo,Mo/Rh,Rh/Rh anode/filter combination by automatic exposure control,record the exposure factors and doses.The images on monitor with the best window width and window level were read by 4 independent radiologists,the images of specks groups,nylon fibers and masses was assessed by the 4 experienced readers at the criterion of American College of Radiology 1999 mammography quality control manual.Statistical analysis was performed using analysis of variance.Results The nylon fibers scores of Mo/Mo,Mo/Rh and Rh/Rh were 5.50 ± 2.12,4.50 ± 1.85 and 4.38 ± 1.38 ; the specks groups scores of Mo/Mo,Mo/Rh and Rh/Rh were 5.38 ± 1.98,4.25 ± 1.56 and 4.38 ± 1.38;the masses scores of Mo/Mo,Mo/Rh and Rh/Rh were 5.38 ± 1.98,4.38 ±1.68 and 4.25 ± 1.56,the detection of specks groups,nylon fibers was not statistically significant ( F =4.56 and 4.32,P ＞ 0.05 ),but the detection of masses was statistically significant ( F =36.65,P ＜ 0.05).The radiation doses were different,the entrance surface dose (ESD) and average glandular dose (AGD) of Rh/Rh were (5.11 ± 1.89) and ( 1.08 ± 0.13 ) mGy,the ESD and AGD of Mo/Mo were (6.66 ± 2.33 )and ( 1.29 ± 0.38 ) mGy,the ESD and AGD of Mo/Rh anode/filter combination were (5.67 ± 2.02) and ( 1.29 ± 0.38) mGy.Conclusions The radiation dose of Rh/Rh and Mo/Rh anode/filter combination of FFDM were lower,and the imaging was clear,so Rh/Rh and Mo/Rh anode/filter combination of FFDM prefer to mostly patients,especially when the thinkness is large,Rh/Rh anode/filter combination is preferred,because the kV values was higher,the penetration of X-ray was stronger.The Mo/Mo anode/filter combination was used when the needs of high-resolution,because the detection of masses of it was better. Key words: Mammography; Radiation dose; Comparative study