Patent
Methods and apparatus for artifact compensation with variable angular sampling
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TLDR
In this article, the angular spacing between samples of projection data as a function of the projection angle is altered to reduce the aliasing artifacts by using a digital detector array, and a complete volumetric image is generated from the data.Abstract:
The present invention, in one form, includes an imaging system (10) having a x-ray source (14) and a digital detector array (18). The system (10) alters an angular spacing between samples of projection data as a function of the projection angle so that aliasing artifacts are reduced. More specifically and in one embodiment, after identifying at least two projection angle regions, a first view sampling rate is utilized to collect projection data for the first region. As the projection angle becomes equal to the second region, the view sampling rate is altered to a second view sampling rate. A complete volumetric image (42) of an object is then generated (36) from the data.read more
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References
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Patent
Apparatus and method for computed tomography scanning using halfscan reconstruction with asymmetric detector system
TL;DR: In this article, a method and apparatus for half-scan reconstruction in a CT scanning system using an asymmetric detector system is described, which applies a zero weighting to data acquired by the asymmetric portion of the array.
Patent
Constant image quality CT scanner with variable radiation flux density
TL;DR: In this article, an x-ray source rotates about a fixed cylinder, within which a subject of non-uniform cross-section is received, and the average energy fluence impinging on the detectors across the arc varies with the relative angular position of the source and the subject.
Patent
Method and apparatus for helical computed tomography scanning with asymmetric detector system
TL;DR: In this article, an improved helical weighting system applies a helical half-scan technique to data collected by a symmetric portion of an asymmetric detector system and applies a full-scanned helical full-scan algorithm to data obtained by an asymmetrical portion of the asymmetric part of the system.
Patent
Computed-tomography apparatus and control method thereof
TL;DR: In this paper, a computed-tomography apparatus acquires a cross-sectional image of an object from projection data obtained by scanning the object with radiation while rotating a scanner around the object, and the operation of the scanner is controlled to start the scan from the rotation position having the smaller attenuation.
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Tomography data acquisition system
John Dobbs,Bernard M. Gordon +1 more
TL;DR: A tomography data acquisition system in which the signal processing of signals from a radiation detector is a function of the angular position of the detector relative to a center path from the radiation source through the center of a tomography subject, and which results in system hardware savings is discussed in this paper.