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 language | English |
|---|---|
| Pages (from-to) | 699-706 |
| Number of pages | 8 |
| Journal | Proceedings of SPIE - The International Society for Optical Engineering |
| Volume | 914 |
| DOIs | |
| Publication status | Published - 1988 Jun 27 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Applied Mathematics
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Computer Science Applications
Cite this
Correction of collimator aperture using a shift-variant deconvolution filter in gamma camera emission ct. / Ogawa, Koichi; Paek, Seungkuen; Nakajima, Masato; Yuta, Shinichi; Kubo, Atsushi; Hashimoto, Shozo.
In: Proceedings of SPIE - The International Society for Optical Engineering, Vol. 914, 27.06.1988, p. 699-706.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Correction of collimator aperture using a shift-variant deconvolution filter in gamma camera emission ct
AU - Ogawa, Koichi
AU - Paek, Seungkuen
AU - Nakajima, Masato
AU - Yuta, Shinichi
AU - Kubo, Atsushi
AU - Hashimoto, Shozo
PY - 1988/6/27
Y1 - 1988/6/27
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84957476659&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84957476659&partnerID=8YFLogxK
U2 - 10.1117/12.968702
DO - 10.1117/12.968702
M3 - Article
VL - 914
SP - 699
EP - 706
JO - Proceedings of SPIE - The International Society for Optical Engineering
JF - Proceedings of SPIE - The International Society for Optical Engineering
SN - 0277-786X
ER -