Rickard M T
Australas Radiol. 1989 Nov;33(4):328-34. doi: 10.1111/j.1440-1673.1989.tb03305.x.
Seven major factors resulting in a quality or high contrast and high resolution mammographic image have been discussed. The following is a summary of their key features: 1) Dedicated mammographic equipment. --Molybdenum target material --Molybdenum filter, beryllium window --Low kVp usage, in range of 24 to 30 --Routine contact mammography performed at 25 kVp --Slightly lower kVp for coned compression --Slightly higher kVp for microfocus magnification 2) Film density --Phototimer with adjustable position --Calibration of phototimer to optimal optical density of approx. 1.4 over full kVp range 3) Breast Compression --General and focal (coned compression). --Essential to achieve proper contrast, resolution and breast immobility. --Foot controls preferable. 4) Focal Spot. --Size recommendation for contact work 0.3 mm. --Minimum power output of 100 mA at 25 kVp desirable to avoid movement blurring in contact grid work. --Size recommendation for magnification work 0.1 mm. 5) Grid. --Usage recommended as routine in all but magnification work. 6) Film-screen Combination. --High contrast--high speed film. --High resolution screen. --Specifically designed cassette for close film-screen contact and low radiation absorption. --Use of faster screens for magnification techniques. 7) Dedicated processing. --Increased developing time--40 to 45 seconds. --Increased developer temperature--35 to 38 degrees. --Adjusted replenishment rate and dryer temperature. All seven factors contributing to image contrast and resolution affect radiation dosage to the breast. The risk of increased dosage associated with the use of various techniques needs to be balanced against the risks of incorrect diagnosis associated with their non-use.(ABSTRACT TRUNCATED AT 250 WORDS)
本文讨论了生成高质量、高对比度和高分辨率乳腺钼靶图像的七个主要因素。以下是其关键特征总结:1)专用乳腺钼靶设备。——钼靶材料——钼滤过、铍窗——低千伏使用,范围在24至30——常规接触式乳腺钼靶摄影在25千伏进行——锥形压迫时千伏略低——微焦点放大时千伏略高2)胶片密度——位置可调的光电计时器——将光电计时器校准至在整个千伏范围内约1.4的最佳光学密度3)乳房压迫——一般压迫和局部(锥形压迫)。——对于获得适当的对比度、分辨率和乳房固定至关重要。——脚踏控制更佳。4)焦点。——接触式摄影推荐尺寸为0.3毫米。——在25千伏时最小功率输出为100毫安,以避免接触式格栅摄影中的运动模糊。——放大摄影推荐尺寸为0.1毫米。5)格栅。——除放大摄影外,建议常规使用。6)胶片-增感屏组合。——高对比度——高速胶片。——高分辨率增感屏。——专门设计的暗盒,用于紧密的胶片-增感屏接触和低辐射吸收。——放大技术使用更快的增感屏。7)专用处理。——增加显影时间——40至45秒。——提高显影剂温度——35至38度。——调整补充率和干燥温度。所有这七个影响图像对比度和分辨率的因素都会影响乳房的辐射剂量。使用各种技术导致剂量增加的风险需要与不使用这些技术而导致错误诊断的风险相权衡。(摘要截断于250字)