The noise power spectrum in computed X-ray tomography

Stephen J Riederer, N. J. Pelc, D. A. Chesler

Research output: Contribution to journalArticle

157 Citations (Scopus)

Abstract

An expression is derived showing that the two-dimensional noise power spectrum of computed X-ray tomography is proportional to mod G(k) mod 2/k where k is the radial spatial frequency and G(k) is the one-dimensional corrective filter used in the filtered back-projection reconstruction technique. It is shown that predicted noise power spectra compare well with those estimated from CT reconstructions of simulated noise for both the ramp filter and the Hanning-weighted ramp filter. A consequence of the non-uniform shape of the noise power spectrum is that statistical noise in CT reconstructions is correlated from point to point. Because of this correlation when the reconstructed CT values are averaged over some region, the uncertainty of the average depends on the shape of the region as well as its area. This dependence is confirmed by computer simulations.

Original languageEnglish (US)
Article number008
Pages (from-to)446-454
Number of pages9
JournalPhysics in Medicine and Biology
Volume23
Issue number3
DOIs
StatePublished - 1978
Externally publishedYes

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Architectural Accessibility
X Ray Computed Tomography
noise spectra
Power spectrum
Tomography
power spectra
tomography
ramps
filters
X rays
Computer Simulation
Uncertainty
Noise
x rays
computerized simulation
projection
Computer simulation

ASJC Scopus subject areas

  • Biomedical Engineering
  • Radiology Nuclear Medicine and imaging
  • Physics and Astronomy (miscellaneous)
  • Radiological and Ultrasound Technology

Cite this

The noise power spectrum in computed X-ray tomography. / Riederer, Stephen J; Pelc, N. J.; Chesler, D. A.

In: Physics in Medicine and Biology, Vol. 23, No. 3, 008, 1978, p. 446-454.

Research output: Contribution to journalArticle

Riederer, Stephen J ; Pelc, N. J. ; Chesler, D. A. / The noise power spectrum in computed X-ray tomography. In: Physics in Medicine and Biology. 1978 ; Vol. 23, No. 3. pp. 446-454.
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