Improved image quality for asymmetric double-focal cone-beam SPECT

Journal Article · Sun Aug 01 00:00:00 EDT 1993 · IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States)

DOI:https://doi.org/10.1109/23.256726· OSTI ID:6062230

Cao, Z J; Tsui, B M.W. ^[1]

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1. Univ. of North Carolina, Chapel Hill, NC (United States)

To optimize both spatial resolution and detection efficiency in brain SPECT imaging using a rectangular camera, an asymmetric double-focal cone-beam collimator is proposed with the focal points located near the base plane of the patient's head. To fit the entire head into the field-of-view of the collimator with dimensions of 50cmx40cm and at a radius-of-rotation of 15 cm, the focal lengths of the collimator are 55 and 70 cm, respectively, in the transverse and axial directions. With this geometry, the artifacts in the reconstructed image produced by the Feldkamp algorithm are more severe compared to those in a symmetric cone-beam geometry, due to the larger vertex angle between the top of the head and the base plane. To improve the reconstructed image quality, a fully three-dimensional (3D) reconstruction algorithm developed previously for single-focal cone-beam SPECT was extended to the asymmetric double-focal cone-beam geometry. The algorithm involves nonstationary 2D filtering and a reprojection technique for estimation of the missing data caused by a single-orbit cone-beam geometry. The results from simulation studies with the 3D Defrise slab phantom demonstrated that the fully 3D algorithm provided a much improved image quality in terms of reduced slice-to-slice cross talks and shape elongation compared to that produced by the conventional Feldkamp algorithm.

• OSTI ID: 6062230
• Journal Information: IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States), Journal Name: IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States) Vol. 40:4 part 1; ISSN 0018-9499; ISSN IETNAE
• Country of Publication: United States
• Language: English

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550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ALGORITHMS
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BRAIN
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COLLIMATORS
COMPUTERIZED TOMOGRAPHY
CONTROL
DIAGNOSTIC TECHNIQUES
EFFICIENCY
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ORGANS
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