The noise power spectrum of CT images.
Phys Med Biol
; 32(5): 565-75, 1987 May.
Article
em En
| MEDLINE
| ID: mdl-3588670
ABSTRACT
An expression for the noise power spectrum of images reconstructed by the discrete filtered backprojection algorithm has been derived. The formulation explicitly includes sampling within the projections, angular sampling, and the two-dimensional sampling implicit in the discrete representation of the image. The effects of interpolation are also considered. Noise power spectra predicted by this analysis differ from those predicted using continuous theory in two respects they are rotationally asymmetric, and they do not approach zero at zero frequency. Both of these properties can be attributed to two-dimensional aliasing due to pixel sampling. The predictions were confirmed by measurement of noise power spectra of both simulated images and images from a commercial x-ray transmission CT scanner.
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Base de dados:
MEDLINE
Assunto principal:
Tomografia Computadorizada por Raios X
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
1987
Tipo de documento:
Article