Correction of collimator aperture using a shift-variant deconvolution filter in gamma camera emission ct

Koichi Ogawa, Seungkuen Paek, Masato Nakajima, Shinichi Yuta, Atsushi Kubo, Shozo Hashimoto

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

We propose a new method which enables improved spatial resolution of a reconstructed image from a gamma camera emission CT(SPECT). SPECT images are blurred due to the effect of the collimator aperture. The blur effect changes with the geometrical structure of the collimator and with the distance between the rotational center of the gamma camera and the collimator surface. The acquired projection, affected by the collimator aperture, can be assumed to be the convolution of the ideal projection by the shift-variant blur functions. So the measured projection will be represented as a weighted summation of neighboring ideal projections of different angles and positions. From this standpoint, the blur function can be defined as a function of a common spatial frequency in the Fourier domain. Hence the deconvolution of the measured projection was circularly processed in the frequency domain. The effectiveness of the method was proven by simulations involving various aperture angles and the distances between the collimator surface and the rotational center.

Original languageEnglish
Pages (from-to)699-706
Number of pages8
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume914
DOIs
Publication statusPublished - 1988 Jun 27
Externally publishedYes

ASJC Scopus subject areas

  • Applied Mathematics
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Computer Science Applications

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