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Proceedings Paper

Correction Of Collimator Aperture Using A Shift-Variant Deconvolution Filter In Gamma Camera Emission CT
Author(s): Koichi Ogawa; Seungkuen Paek; Masato Nakajima; Shin'ichi Yuta; Atsushi Kubo; Shozo Hashimoto
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Paper 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.

Paper Details

Date Published: 27 June 1988
PDF: 8 pages
Proc. SPIE 0914, Medical Imaging II, (27 June 1988); doi: 10.1117/12.968702
Show Author Affiliations
Koichi Ogawa, Keio University (Japan)
Seungkuen Paek, Keio University (Japan)
Masato Nakajima, Keio University (Japan)
Shin'ichi Yuta, The University of Tsukuba (Japan)
Atsushi Kubo, Keio University (Japan)
Shozo Hashimoto, Keio University (Japan)

Published in SPIE Proceedings Vol. 0914:
Medical Imaging II
Samuel J. Dwyer III; Roger H. Schneider; Samuel J. Dwyer III; Roger H. Schneider; Roger H. Schneider; Samuel J. Dwyer III, Editor(s)

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