Imaging with rotating slit apertures and rotating collimators
The statistical quality of conventional nuclear medical imagery is limited by the small signal collect through low-efficiency conventional apertures. Coded-aperture imaging overcomes this by employing a two-step process in which the object is first efficiently detected as an ''encoded'' form which does not resemble the object, and then filtered (or ''decoded'') to form an image. We present here the imaging properties of a class of time-modulated coded apertures which, unlike most coded apertures, encode projections of the object rather than the object itself. These coded apertures can reconstruct a volume object nontomographically, tomographically (one plane focused), or three-dimensionally. We describe a new decoding algorithm that reconstructs the object from its planar projections. Results of noise calculations are given, and the noise performance of these coded-aperture systems is compared to that of conventional counterparts. A hybrid slit-pinhole system which combines the imaging advantages of a rotating slit and a pinhole is described. A new scintillation detector which accurately measures the position of an event in one dimension only is presented, and its use in our coded-aperture system is outlined. Finally, results of imaging test objects and animals are given.
- Research Organization:
- University of Arizona, Tucson, Arizona 85721
- OSTI ID:
- 5395766
- Journal Information:
- Med. Phys.; (United States), Vol. 9:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
61 RADIATION PROTECTION AND DOSIMETRY
NUCLEAR MEDICINE
IMAGE PROCESSING
IMAGES
RADIATION DETECTORS
NOISE
SIGNAL-TO-NOISE RATIO
SCINTILLATION COUNTERS
APERTURES
THREE-DIMENSIONAL CALCULATIONS
TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
MEASURING INSTRUMENTS
MEDICINE
OPENINGS
PROCESSING
440100* - Radiation Instrumentation
655000 - Medical Physics