Investigation of basic imaging properties in digital radiography. I. Modulation transfer function.
Investigation of basic imaging properties in digital radiography. I. Modulation transfer function.
复制标题
数字放射线摄影中基本成像特性的研究。
作者：
Giger,ML;Doi,K
通过理论仿真研究了采样孔径、采样距离和显示孔径等数字参数对数字射线成像系统调制传递函数（MTF）的影响。还通过实验确定了MTF，以确认模拟研究中使用的关系。结果表明，数字系统的整体MTF不能以与模拟系统的MTF相同的方式指定分辨率属性。数字系统的MTF可能包括由于混叠而导致的“假”响应，这可能导致对分辨率属性的不正确解释。在数字化信号中出现的混叠幅度取决于所选择的采样参数和被成像的放射学对象的频率内容。因此，在数字成像系统的设计和评估中必须考虑待检测对象的类型以及各种数字参数。
The effect of various digital parameters, such as the sampling aperture, sampling distance, and display aperture, on the modulation transfer function (MTF) of digital radiographic imaging systems was investigated by means of theoretical simulation studies. The MTFs were also determined experimentally to confirm the relationship used in the simulation studies. The results indicate that the overall MTF of a digital system cannot specify the resolution properties in the same way as can the MTFs of analog systems. The MTF of a digital system may include a “false” response due to aliasing, which could lead to an incorrect interpretation of the resolution properties. The magnitude of aliasing that will occur in a digitized signal depends on the sampling parameters chosen and on the frequency content of the radiologic object being imaged. Thus, the type of object to be detected as well as various digital parameters must be considered in the design and evaluation of digital imaging systems.