离散滤波反投影调制传递函数的特性。

Characterization of the modulation transfer function of discrete filtered backprojection.

机构信息

Dept. of Nucl. Med., Massachusetts Univ., Med. Center, Worcester, MA.

出版信息

IEEE Trans Med Imaging. 1989;8(2):203-13. doi: 10.1109/42.24869.

Abstract

A mathematical expression for the modulation transfer function (MTF) of image reconstruction by discrete filtered backprojection (DFBP) is derived. A simulation study is used to investigate the dependence of the MTF of DFBP on: (1) the number of projection views; (2) the type of ramp filter used; (3) the interpolation method used during backprojection; and (4) the position of the object. These results were compared to MTFs calculated from point-source single-photon-emission computed tomographic (SPECT) acquisitions in air. The experimentally obtained MTFs contained much of the same structure as the MTFs of DFBP obtained through simulation. It is shown that the discretization of the filtered backprojection process can cause the tomographic transfer function to be anisotropic and nonstationary. However, through proper selection of the methods used in reconstruction, a nearly isotropic and stationary MTF can be obtained.

摘要

推导出了离散滤波反投影（DFBP）图像重建调制传递函数（MTF）的数学表达式。通过模拟研究，研究了DFBP 的 MTF 对以下因素的依赖关系：（1）投影视图的数量；（2）使用的斜坡滤波器的类型；（3）反投影过程中使用的插值方法；（4）物体的位置。将这些结果与空气中的点源单光子发射计算机断层扫描（SPECT）采集的 MTF 进行了比较。实验获得的 MTF 与通过模拟获得的 DFBP 的 MTF 具有相同的结构。结果表明，滤波反投影过程的离散化会导致层析转移函数具有各向异性和非平稳性。然而，通过适当选择重建中使用的方法，可以获得几乎各向同性和稳定的 MTF。