乳腺数字图像之软阅读与平均像素分析  

Soft Reading and Average Pixel Analysis of Mammary Digital Imaging

作　　者：宋俊峰[1] 王洪霞[1] 

机构地区：[1]中国医学科学院肿瘤医院影像诊断科,北京100210

出　　处：《中国医疗设备》2011年第3期4-5,3,共3页China Medical Devices

摘　　要：目的探讨乳腺数字图像兴趣区的平均像素值与窗宽、窗位的关联性。方法使用环境照度计测量环境照度;环境照度满足要求后,进行后续测量。使用屏幕亮度计测量图像灰阶亮度;应用测量软件测量18-222模体照射图像(3种自动摄影模式)兴趣区平均像素值。以灰阶对应平均像素值作为窗位进行调节。结果①测试图像的平均像素值与灰阶亮度的改变具有负相关,平均像素值越大亮度值反而越低;②18-222模体摄影图像兴趣区的平均像素数值与其接受射线剂量成负相关(Dose模式剂量最低,CNT模式剂量最大)。③3种模式有各自的亮度显示区间,窗技术[2]调整明显改变灰阶显示亮度,但不改变平均像素测量值。④平均像素值接近图像显示窗位默认的数值。结论①窗口技术应用不影响图像兴趣区平均像素值测量准确性。②数字图像兴趣区平均像素数值与射线剂量成负相关。③数字图像兴趣区平均像素数值与显示器亮度具有线性负相关。④数字图像兴趣区的平均像素数值,可作为图像窗位设置的重要参考值,不建议用单一兴趣区平均像素数值作为整体图像窗位设置的阅读标准。⑤窗宽控制可显示的灰阶(或平均像素值)范围。Objective To explore the correlation between the mean pixels of digital mammogram interest and window width and window level.Methods Used environmental luxmeter,measuring environment illumination.When the illuminance meet the requirements,measurement is go on.Use screen Luminance-meter,measuring image gray-scale.Use the software,measuring the mean pixels of 18-222 phantom interest,The mean pixel corresponded the gray-scale can be used to adjust the window level.Results ① The mean pixels and the change of gray-scale brightness is negatively related;② The mean pixels of 18-222 phantom interest and the dose received is negatively related（Dose mode lowest,CNT mode highest）.③ Three models have their brightness interval,The Window technology adjustment changes gray-scale brightness obviously,but don＇t change the mean pixel.④ The mean pixels closed the window level of imge.Conclusion ① The application of window technology does not affect the accuracy of imge pixels measurement.② The mean pixels and the Radiation dose is negatively related.③ The mean pixels and monitor brightness is negatively related to the linear.④ Mean pixel can be used as a important reference to set image window level.But,not suggest using mean pixel of a single area as standards to set a whole image window levle.⑤ Window wide control the range of gray-scale（or mean pixels） displayed.

关 键 词：乳腺数字图像 乳腺摄影 软阅读 平均像素 灰阶亮度 窗宽窗位 

分 类 号：TH774[机械工程—仪器科学与技术]