大宽容度T—颗粒感绿胶片对胸部成像质量与照射量的探讨

A study of image quality and radiation dose with T - grain of wide latitude films for chest radiography

目的 探讨T-颗粒感绿胶片与普通感蓝胶片,在临床上对胸部成像质量和患者表皮剂量的效果实验。方法 应用Agfa ST-L绿片和Koda XK-I蓝片,对不同年龄和性别进行胸部照相和表皮剂量的分析。结果 绿组感光度高,对胸部隐匿区组织显示率绿片显示的细节明显地高于蓝组,铝梯测定在0.2～2.00D的诊断区域,显示的灰阶绿组为14级,蓝组为10级。绿组相对剂量低,正位胸部绿组平均为0.076mGy,蓝组平均为0.133mGy。结论 绿组感光速度快,蓝组感光度慢,并且绿组的成像细节和层次优于蓝组,特别在隐匿区(如心脏、纵隔和横膈下)组织的显示率绿组明显高于蓝组。两片在等密度下比较,绿组的表皮剂量比蓝组可降低到57％。

Purpose To study the value of T - grain films by using the image quality and reduction of radiation dose for chest radiography. Methods To test and analyze the image quality and radiation dose for Agfa ST- L( green films) and Kodak XK- I(blue films) in different sex and age of patients. Results The green films had higher sensitivity and better visualization of the structures of super-imposition regions than the blue films in chest radiography. Experiment of an aluminum step wedge demonstrating change in diagnosticaly useful densities of the range from 0.25 to 2.00 D with green films were 14 gray scales,but blue films only 10 gray scales. The green films took low radiation dose in exposure,as for chest radiography of dose in green films(average)0.076mGy and blue films(average)0.133mGy. Conclusion The green films had higher sensitivity than blue films. The chest radiographic images of detail and sharpness with green films were also better than with blue films, especially in the superimposition of regions ( for example posterior heart, mediastimum and inferior diaphragma). On equal density, green films got less radiation dose than blue films and the dose could be reduced to 57 % .