Department of Radiology, Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27710, USA.
Med Phys. 2010 Mar;37(3):962-9. doi: 10.1118/1.3276732.
Digital mammography requires revisiting techniques that have been optimized for prior screen/film mammography systems. The objective of the study was to determine optimized radiographic technique for a digital mammography system and demonstrate the potential for dose reduction in comparison to the clinically established techniques based on screen- film. An objective figure of merit (FOM) was employed to evaluate a direct-conversion amorphous selenium (a-Se) FFDM system (Siemens Mammomat Novation(DR), Siemens AG Medical Solutions, Erlangen, Germany) and was derived from the quotient of the squared signal-difference-to-noise ratio to mean glandular dose, for various combinations of technique factors and breast phantom configurations including kilovoltage settings (23-35 kVp), target/filter combinations (Mo-Mo and W-Rh), breast-equivalent plastic in various thicknesses (2-8 cm) and densities (100% adipose, 50% adipose/50% glandular, and 100% glandular), and simulated mass and calcification lesions. When using a W-Rh spectrum, the optimized FOM results for the simulated mass and calcification lesions showed highly consistent trends with kVp for each combination of breast density and thickness. The optimized kVp ranged from 26 kVp for 2 cm 100% adipose breasts to 30 kVp for 8 cm 100% glandular breasts. The use of the optimized W-Rh technique compared to standard Mo-Mo techniques provided dose savings ranging from 9% for 2 cm thick, 100% adipose breasts, to 63% for 6 cm thick, 100% glandular breasts, and for breasts with a 50% adipose/50% glandular composition, from 12% for 2 cm thick breasts up to 57% for 8 cm thick breasts.
数字乳腺 X 线摄影需要重新审视那些针对传统屏片乳腺摄影系统进行了优化的技术。本研究旨在确定数字乳腺 X 线摄影系统的优化放射技术,并与基于屏片的临床既定技术相比,展示降低剂量的潜力。采用客观品质因数(FOM)来评估直接转换非晶硒(a-Se)FFDM 系统(西门子 Mammomat Novation(DR),西门子医疗解决方案公司,德国埃尔兰根),该因数源自平方信号差异噪声比与腺体剂量均值的商,用于不同技术因素和乳腺体模配置的组合,包括千伏设置(23-35 kVp)、靶/滤器组合(钼-钼和钨-铱)、不同厚度(2-8 cm)和密度(100%脂肪、50%脂肪/50%腺体和 100%腺体)的乳腺等效塑料以及模拟肿块和钙化病变。当使用钨铱光谱时,模拟肿块和钙化病变的优化 FOM 结果对于每种乳腺密度和厚度组合的千伏值显示出高度一致的趋势。优化的千伏值范围从 2 cm 100%脂肪乳腺的 26 kVp 到 8 cm 100%腺体乳腺的 30 kVp。与标准钼-钼技术相比,使用优化的钨铱技术可提供从 2 cm 厚、100%脂肪乳腺的 9%到 6 cm 厚、100%腺体乳腺的 63%的剂量节省,对于 50%脂肪/50%腺体组成的乳腺,从 2 cm 厚乳房的 12%到 8 cm 厚乳房的 57%。