Transmission and emission SPECT imaging of attenuator and source distributions larger than the camera field of view
- Univ. of Massachusetts Medical Center, Worcester, MA (United States)
Cross-sections of patients may be truncated when imaged with a fan beam collimator or even a parallel hole collimator on the 40 cm width camera head of a typical 3-headed SPECT system. Currently, even iterative reconstruction methods are unable to reliably reconstruct the truncated part of cross-sections. Truncation of transmission and emission images can be avoided by using a slant hole collimator and combining conjugate views. Enclosing the center-of-rotation at the largest radius of rotation in the region consistently viewed by the slant hole collimator guarantees no truncation for all patients who can be accommodated between the heads. Smaller patients require smaller radii of rotation. This increases the overlap of the conjugate views thereby increasing sensitivity near the center. Once the composite view is formed, parallel-ray filtered backprojection can be used in reconstruction. For transmission imaging, a slant hole collimator is employed on one head and a moving line source is mounted on another head in the direction viewed by the collimator. For emission imaging, one or more slant hole collimators can be used. A preliminary investigation of the use of these principles was conducted using a 30 degree slant hole collimator on a prism 3000 SPECT system. For transmission imaging, a stationary line source was employed. It was determined that truncation free attenuation maps could be obtained of phantoms which were up to 60 cm in cross-section.
- OSTI ID:
- 197962
- Report Number(s):
- CONF-940605--
- Journal Information:
- Journal of Nuclear Medicine, Journal Name: Journal of Nuclear Medicine Journal Issue: Suppl.5 Vol. 35; ISSN JNMEAQ; ISSN 0161-5505
- Country of Publication:
- United States
- Language:
- English
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