基于调制传递函数对CT图像空间分辨率质量评估的分析

Analysis on spatial resolution quality of CT image based on the modulation transfer function

目的:对质量检测的重要参数CT图像空间分辨率进行质量评估分析。方法:通过尝试使用Catphan500 CT性能测试体模中直径为0.28 mm的钨珠模拟点源,构建图像系统点扩散函数(PSF),继而使用评价成像系统空间分辨力特性常用的方法调制传递函数(MTF)对CT图像进行空间分辨率的测定。结果:采用PSF和MTF的方法,其结果不仅方便,准确地用于对机器空间分辨率的测定,而且蕴含了更多的信息。结论:采用PSF和MTF方法可有效提高测试结果的准确性以及唯一性,值得推广。

Objective： To analyze spatial resolution quality of CT image which is an important parameter of quality detection based on the modulation transfer function. Methods： Tungsten ball with diameter of 0.28nm in Catphan500 CT Performance testing body model was used to simulate point source to establish point spread function of image. Then modulation transfer function, which is commonly used for spatial resolution feature assessment of imaging system, was further used to assess spatial resolution of CT image. Results： By applying point spread function and modulation transfer function, assessment result was more accurate and more unique, and there was more information. Conclusion： application of point spread function and modulation transfer function can effectively improve accuracy and uniqueness of assessment result, which is worthy of wider application.