两种数字化X射线摄影技术影像质量与成像剂量的比较  

Comparison between two different digital radiographic techniques:image quality versus imaging dose

作　　者：王鹏程[1] 张富利[1] 李士俊[2] 

机构地区：[1]泰山医学院放射学院,271000 [2]苏州大学放射医学与公共卫生学院

出　　处：《中华放射医学与防护杂志》2005年第1期91-93,共3页Chinese Journal of Radiological Medicine and Protection

摘　　要：目的　对比研究非晶硒平板探测器直接数字化X射线摄影 (DR)及计算机X射线摄影(CR)两种数字化X射线摄影技术影像质量与吸收剂量的关系。方法　应用DR和CR系统分别对对比度 细节体模 (CDRAD 2 0 )进行不同吸收剂量的曝光成像。记录每次曝光的体模表面吸收剂量 ,并将所获取的影像在图像诊断工作站显示器上由 4位观片者进行观察 ,计算影像质量表征因子(IQF)。应用ANOVA检验法统计、比较两种数字化摄影技术的图像质量与吸收剂量的差别。结果与CR相比 ,DR具有更低的IQF值 ,对人体组织对比度和结构细节有更好的信息检出特性。两种成像技术产生相同IQF值时 ,DR系统在体模表面产生的表面剂量比CR系统降低了 77%。结论　DR技术对于低对比度组织细节的检测好于CR技术。在获得相同影像信息的前提下 ,与CR相比应用DR大大降低了被检者吸收剂量。Objective To assess and compare the difference in image quality and exposure dose between an amorphous selenium flat panel digital radiography(DR) system and computed radiography(CR). Methods A contrast-detail phantom CDRAD2.0 was exposed by DR and CR with different mAs sets.The entrance surface doses were recorded for all images.Images were presented to 4 independent observers on a higher resolution monitor of diagnosis work station.The image quality figure(IQF)was measured for each image.Statistical analysis was performed using ANOVA test to compare the difference in image quality and exposure dose between DR and CR. Results Comparing to CR,DR had a lower IQF,ensuring a high image quality with respect to contrast and detail detectability.When IQFs for DR and CR were equal,DR could reduce the surface dose by 77% of that of CR. Conclusion Image quality of DR has been proved to be far superior to CR,in particular for contrast-detail.The image quality of CR is similar to that of DR only at very high dose levels.The clinical application of DR will reduce the exposure dose to the patient greatly.

关 键 词：吸收剂量 体模 数字化X射线摄影 DR 影像质量 CR系统 X射线摄影 光成像 量比 降低 

分 类 号：R814.41[医药卫生—影像医学与核医学]