High-contrast resolution of CT images for bone structure analysis.
The modulation transfer function (MTF) of an imaging system may be used as a figure of merit to assess its geometrical resolution. As such it is often derived from the point spread function (PSF) through a Fourier transformation, or through a FFT in case of digital images. Using the special features of the convolution-backprojection algorithm and making some simplifying assumptions about the number of rays, it is shown that the desired MTF is also obtainable without a Fourier transformation of the PSF, different shapes and sizes of the beam-profile are then analyzed, and finally it is shown that calculated and measured MTF functions are in good agreement. The effects of aliasing on the cutoff frequency are also discussed.
Durand
E P
EP
Institute for Biomedical Engineering, University of Zürich, Switzerland.
Rüegsegger
P
P
D000368:Aged; D001842:Bone and Bones / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D005260:Female; D005360:Fibula / Q000000981:diagnostic imaging; D005583:Fourier Analysis; D006801:Humans; D008433:Mathematics; D013977:Tibia / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods*