Dimakopoulou A D, Tsalafoutas I A, Georgiou E K, Yakoumakis E N
Medical Physics Department, Medical School, University of Athens, 75 Mikras Asias, 115 27, Athens, Greece.
Br J Radiol. 2006 Feb;79(938):123-9. doi: 10.1259/bjr/84646476.
In this study the effect of different mammographic screen-film combinations on image quality and breast dose, and the correlation between the various image quality parameters, breast dose and the sensitometric parameters of a film were investigated. Three Agfa (MR5-II, HDR, HT), two Kodak (Min-R M, Min-R 2000), one Fuji (AD-M), one Konica (CM-H) and one Ferrania (HM plus) single emulsion mammographic films were combined with three intensifying screens (Agfa HDS, Kodak Min-R 2190 and Fuji AD-MA). The film characteristics were determined by sensitometry, while the image quality and the dose to the breast of the resulting 24 screen-film combinations were assessed using a mammography quality control phantom. For each combination, three images of the phantom were acquired with optical density within three different ranges. Two observers assessed the quality of the 72 phantom images obtained, while the breast dose was calculated from the exposure data required for each image. Large differences among screen-film combinations in terms of image quality and breast dose were identified however, that, could not be correlated with the film's sensitometric characteristics. All films presented the best resolution when combined with the HDS screen at the expense of speed, and the largest speed when combined with the AD-MA screen, without degradation of the overall image quality. However, an ideal screen-film combination presenting the best image quality with the least dose was not identified. It is also worth mentioning that the best performance for a film was not necessarily obtained when this was combined with the screen provided by the same manufacturer. The results of this study clearly demonstrate that comparison of films based on their sensitometric characteristics are of limited value for clinical practice, as their performance is strongly affected by the screens with which they are combined.
在本研究中，调查了不同乳腺钼靶增感屏 - 胶片组合对图像质量和乳腺剂量的影响，以及各种图像质量参数、乳腺剂量与胶片感光测定参数之间的相关性。将三种爱克发（MR5-II、HDR、HT）、两种柯达（Min-R M、Min-R 2000）、一种富士（AD-M）、一种柯尼卡（CM-H）和一种费拉尼亚（HM plus）单乳剂乳腺钼靶胶片与三种增感屏（爱克发HDS、柯达Min-R 2190和富士AD-MA）进行组合。通过感光测定确定胶片特性，同时使用乳腺钼靶质量控制模体评估所得24种增感屏 - 胶片组合的图像质量和乳腺剂量。对于每种组合，在三个不同的光学密度范围内采集模体的三张图像。两名观察者评估所获得的72幅模体图像的质量，同时根据每张图像所需的曝光数据计算乳腺剂量。然而，发现增感屏 - 胶片组合在图像质量和乳腺剂量方面存在很大差异，且这些差异与胶片的感光测定特性无关。所有胶片与HDS增感屏组合时呈现出最佳分辨率，但牺牲了速度，与AD-MA增感屏组合时速度最快，且整体图像质量未下降。然而，未找到一种以最低剂量呈现最佳图像质量的理想增感屏 - 胶片组合。还值得一提的是，胶片与同一制造商提供的增感屏组合时不一定能获得最佳性能。本研究结果清楚地表明，基于感光测定特性对胶片进行比较在临床实践中的价值有限，因为它们的性能会受到与其组合的增感屏的强烈影响。
