Artifacts on lung CT scans: removal with Fourier filtration.
A preliminary study was done of Fourier analysis of high-resolution computed tomographic (CT) images of normal pulmonary parenchyma. A two-dimensional fast Fourier transform was applied to 20 regions of interest (64 x 64 pixels) obtained from CT images of six lungs. A qualitative analysis of the spectra and the application of filters in the frequency domain allowed the characterization and removal of reconstruction artifacts. Selective application of a low-pass filter removed these parasitic frequencies and clearly enhanced the quality of the image.
Helenon
O
O
Laboratory of Experimental Radiology, Faculty of Medicine Lariboisiere, Paris, France.
Chanin
D S
DS
Laval-Jeantet
M
M
Frija
J
J
D005374:Filtration / Q000379:methods; D005583:Fourier Analysis; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*