The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 02, 1996
Filed:
Dec. 27, 1994
Grant T Gullberg, Salt Lake City, UT (US);
Gengsheng L Zeng, Salt Lake City, UT (US);
The University of Utah, Salt Lake City, UT (US);
Abstract
A SPECT camera system has three detector heads (12a, 12b, 12c). Each of the detectors have a fan-beam collimator (14) disposed toward an examination region (10). The detectors receive radiation travelling along a fan of rays from an apex (x.sub.f,y.sub.f) to a planar face of the detectors. The detectors generate electronic data indicative of a location (x.sub.s,y.sub.s) on the detector at which a radiation event is received along a ray q.sub..beta. (s). The detectors in a selected orbit R(.beta.) around a subject within the examination region (10). A backprojector (56) includes a backprojection trajectory calculating processor (60) that calculates a trajectory through image space, hence through an image memory (58), corresponding to each radiation ray q.sub..beta. (s). The backprojector weights (68) each data value (x.sub.s,y.sub.s) with a weighting function, preferably a Jacobian J(r,.phi.,.beta.), and adds (64) each weighted data value to a corresponding memory cell of the image memory (58). An indexer (62) indexes the memory addresses (66) in the image memory to index the memory cells to which the weighted data value is added and indexes the weighting function (54) such that the weighting function changes along the trajectory. With the preferred 1/r weighting function, where r is distance along a radial polar coordinate in image space, the resultant image is blurred. The blurring is removed by deconvolving (70) the blurred image representation in accordance with 1/r to generate a corrected image stored in a corrected image memory (80).