【摘要】 目的 探讨数字乳腺X线摄影不同阳极靶∕滤过组合对辐射剂量和图像质量的影响。方法 首先采用自动曝光模式对44 mm、54 mm和64 mm的乳腺模体曝光，然后选择与自动曝光模式相近的管电压和管电流范围，采用钼∕钼(Mo/Mo)、钼∕铑(Mo/Rh)、铑∕铑(Rh/Rh)3种靶∕滤过组合对以上每种厚度的乳腺模体进行手动曝光，记录每次曝光的皮肤入射剂量(ESE)、平均腺体剂量(AGD),计算二者的比值(ESE/AGD),测量图像的信噪比(SNR)、对比噪声比(CNR)和品质因数(FOM),对同一厚度3种靶∕滤过组合的辐射剂量和图像质量参数进行随机区组设计的方差分析。结果 3种厚度不同靶/滤过组合的AGD、ESE和ESE/AGD值的变化规律为Mo/Mo>Mo/Rh>Rh/Rh,差别均有统计学意义(P值均<0.01)。3种厚度均显示Mo/Mo的SNR值最高、FOM值最低，其中Mo/Mo和Mo/Rh之间的SNR差异无统计学意义(P值均>0.05)。44 mm时，Rh/Rh的SNR低于Mo/Rh, Mo/Rh的CNR和FOM均高于Mo/Mo和Rh/Rh,差别均有统计学意义(P值均<0.01)。54 mm和64 mm时，Mo/Mo的CNR和FOM值显著低于Mo/Rh和Rh/Rh(P值均<0.01);Mo/Rh和Rh/Rh之间的CNR和FOM值均无统计学差异(P值均>0.05)。结论 不同靶∕滤过组合对辐射剂量有显著影响，对图像质量的影响与模体厚度有关，厚度越大Mo/Mo的图像质量越差，Rh/Rh的成像性能越好。更多还原

【Abstract】 Objective To explore the effect of different anode-filter combinations on radiation dose and image quality of digital mammography.Methods Firstly,the phantoms with thickness of 44 mm,54 mm and 64 mm were exposed respectively under the automatic exposure control(AEC) mode,and then explored manually under the three different anode-filter combination modes including molybdenum-molybdenum(Mo/Mo),molybdenum-rhodium(Mo/Rh) and rhodium-rhodium(Rh/Rh) combination with the tube voltages and currents similar to the AEC mode,The entrance skin exposure(ESE) and average glandular dose(AGD) were recorded for each exposure.The ESE-to-AGD ratio,signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR) and the figure of merit(FOM) were calculated to compare the radiation dose and image quality of the different anode-filter combinations.The randomized block design analysis of variance was used for statistical analysis.Results For the three phantom thickness,the AGD,ESE and ESEto-AGD ratio in the three anode-filter combinations changed as Mo/Mo>Mo/Rh>Rh/Rh,and the differences were statistically significant(P<0.01);the SNRs of Mo/Mo were the highest,but its FOMs were the lowest;the differences of SNR between Mo/Mo and Mo/Rh had no statistical significance(P>0.05).For the 44 mm phantom thickness,the SNR of Rh/Rh was the lowest,but CNR and FOM of Mo/Rh were the highest,and the differences were all statistically significant(P<0.01).For the 54 mm and 64 mm phantom thickness,CNR and FOM of Mo/Mo were lower than those of the other two combinations,and the differences had statistical significance(P<0.01);the differences between Mo/Rh and Rh/Rh had no statistical significance(P>0.05).Conclusion Different anodefilter combinations have significant influences on radiation dose;the effects on image quality were related to the phantom thickness,the thicker the phantom,the worse the images of Mo/Mo,and the better the performance of Rh/Rh.更多还原