摘要
目的在调制传递函数(MTF)的测量中自动检测点扩展区域中心点位置,可避免手动选点的随意性及噪声对最大CT值的影响。方法根据点扩展区域是圆形的特征,通过图像处理方法分割出圆形区域,再利用数学变换的方法找出中心点位置,绘制MTF曲线。结果自动检测中心点位置的方法简化了CT系统评估的检测流程,得到了正确、稳定的中心点位置,并测得了统一的MTF曲线。结论本文提出的MTF自适应测量方法准确有效,为CT系统评估带来了方便。
Objective Implementing the automatic acquisition of central point position of point spreadregion in MTF measurement to avoid the influence of randomness and noise of manual selection on themaximum CT value. Methods According to the limitation that the shape of point spread region shouldbe roundness, to segment the point spread region with image processing methods and then identify thecentral point position with mathematical transformation methods in order to draw MTF curve. Results Thetest process of CT system evaluation has been simplified with the automatic acquisition method of centralpoint position, with which relevant staff can get the correct and stable central point position and draw thecorrect and unified MTF curve. Conclusion The proposed self-adaption measuring method for MTF isaccurate and effective, which is suitable for CT system evaluation.
出处
《中国医疗设备》
2015年第1期34-36,共3页
China Medical Devices
关键词
CT机
调制传递函数
空间分辨率
CT系统评估
CT machine
modulation transfer function
spatial resolution
CT system evaluation
