指纹影污染变化对库存数字激光胶片质量的影响

目的 :探讨数字激光胶片指纹影污染与硫化银伪影的变化规律 ,以提高胶片的存储质量 .方法 :随机抽取 9a内的MRI胶片 72 0张 ,以 0 .5a时间段分为 1 8组 .采用反射光线和透射光线观察胶片的指纹影和硫化银伪影 ,并根据其污染程度分为 :无、轻度、中度和重度 .采用SPSS统计软件对所得数据进行统计分析 .结果 :指纹影污染在不同时间段分布相差非常显著 (P <0 .0 0 1 ) ,指纹影污染最初多表现为重度 (占98% ) ,在 2～ 3a内逐渐减轻 ,之后随时间延长又出现上升的趋势 ,并渐渐出现有反光的金属伪影 (硫化银伪影 ) .硫化银伪影在不同时间段的分布相差也非常显著 (P <0 .0 0 1 ) ,硫化银伪影与指纹影呈显著正相关 (P <0 .0 0 1 ) .保存 7a以上的胶片可见重度硫化银伪影 ,在白色的伪影区能观察到黄色色斑 .结论 :数字激光胶片上的指纹影随时间的延长 ,将逐渐转变成硫化银伪影 ,影响影像存储质量 ,工作中应尽量减少指纹影污染

Effects of finger marks on image quality of storage digital laser films

AIM: To improve image quality of storage films by exploring finger marks in storage digital laser films. METHODS: 720 MRI films over the past nine years were randomly divided into 18 groups by the time period of 6 months. Reflected light and transmission light were used to detect film artifacts, finger marks and silver sulphide artifacts. By the stained degree, the films were categorized into non stained, light degree, middle degree and high degree. All data were analyzed statistically by a SPSS statistical software. RESULTS: There was marked statistical significance ( P <0.001) in the degrees of finger marks in different time period. In general, although finger marks first displayed high degree (98%), they became more and more inconspicuous gradually within 2-3 years, but then revealed an increased tendency after 2-3 years and turned gradually into metal artifacts (silver sulphide artifacts) with reflected light. There was also marked statistical significance ( P <0.001) in the degrees of silver sulphide artifacts in different time period and there was a significant positive correlation between the degrees of silver sulphide artifacts and that of finger marks ( P <0.001). When films preserved over 7 years were observed, high degree silver sulphide artifacts could been detected and yellow speckles could be seen in the white artifact region. CONCLUSION: In the digital laser film, finger marks will turn into silver sulphide artifacts with the passage of time, which has great harmful effects on the storage image quality. For this reason, measures should be taken to avoid leaving finger marks at work.