迈瑞DigiEye760数字X射线摄影系统成像质量与辐射剂量优化初探

Optimization of image quality and radiation dose for Mindray DigiEye 760 digital radiography system

目的:探讨迈瑞DigiEye760医用数字X射线摄影系统所采用的3种不同图像后处理方法对图像质量与辐射剂量优化的影响。方法:采用对比度阈值测试模块TO20和数字胸部X射线摄影QC体模Model 07-646,测试不同曝光条件及不同图像后处理模式下图像的阈值对比度细节探测力。结果:原始图像受曝光条件的影响较为明显,经过图像后处理和细节增强后,曝光条件对图像质量的影响减轻甚至消失。对于图像对比度细节探测力指数来说,Esa要好于原始图像,增强模式要好于Esa模式;随着曝光管电流的增大,强增强模式提高图像质量的效果逐渐减弱,当曝光管电流提高至200 mA时,强增强模式与弱增强模式具有相同的阈值对比度细节探测力。结论:图像后处理模式可以在较低曝光剂量条件下取得较好的图像阈值对比度细节探测力。只有选取适合的曝光条件,才能做到成像质量与辐射剂量的最大程度优化。

Objective To find the influence of image post-processing methods on the optimization of image quality and radiation dose for Mindray DigiEye 760 digital radiography system.Methods Threshold Contrast Detail Detectability（TCDD） was tested using Threshold Contrast Test Object TO20 and QC Phantom for Digital Chest Radiography Model 07-646 for different exposures conditions and different image post-processing methods.Results The influence of exposure conditions on original image was more significant than on post-processed image.The influence on image quality decreased and even disappeared when using image post-processing and detail enhancement method.TCDD of Esa image was better than that of original image,and TCDD of enhanced image（both ehn1-strong enhancement and ehn2-feeble enhancement） was better than that of Esa image.With the increasing of electric current（mA）,the advantage of image quality for strong enhancement post-processing method trailed off gradually.TCDD became identical for both enh1 and enh2 at 200 mA.Conclusion Image post-processing method could obtain good TCDD at relatively lower exposure conditions.With high exposure conditions,the advantage of post-processing method was weakened.Only when appropriate exposure condition was used could post-processing method be more effective to optimize image quality and radiation dose.