| Autor: |
Matsuo, Hiroshi, Iwata, Akira, Suzumura, Nobuo, Horiba, Isao |
| Předmět: |
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| Zdroj: |
Systems & Computers in Japan; May89, Vol. 20 Issue 5, p96-108, 13p |
| Abstrakt: |
This paper investigates filtered back-projected algorithms for cone-beam X-ray CT reconstruction. A two-dimensional detector array and a cone-beam X-ray source mounted on opposite sides of a cylindrical frame rotate 360 degrees about the object under observation to derive the projection data as a function of the absorption coefficient of the object. A modified ρ filter is proposed for enhancing the incomplete projection data before three-dimensional reconstruction. The modified ρ filter provides two major enhancement functions: (1) It compensates for error in CT value (due to oblique components of X-ray beam) by filtering the data in both the rotation direction and the direction of the axis of the rotation; and (2) recognizing the incompleteness of projection data in the frequency domain, the filter controls the spatial resolution along the axis of the rotation to reduce the amount of artifact in the reconstructed Image. The applications and effectiveness of the modified ρ filter were estimated by computer simulation. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Supplemental Index |
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