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:
Feb. 15, 1977
Filed:
Nov. 28, 1975
Carl J Brunnett, Mayfield Heights, OH (US);
Jerome R Cox, Jr, St. Louis, MO (US);
Donald L Snyder, Clayton, MO (US);
Rodney A Mattson, Mentor, OH (US);
Picker Corporation, Cleveland, OH (US);
Abstract
A dual axial scanner in a transverse tomography system collects nonredundant data throughout one or more substantially 360.degree. orbital scan paths with uniform motion about a patient. A set of N X-ray beams scans the patient in a manner to allow collection of two sets of non-redundant data corresponding to a pair of 180.degree. scans in each 360.degree. scan. Overall time to conduct the study is decreased, and the number of required accelerations and decelerations of the assemblies is minimized. Adjacent beams of radiation are separated by an angle .alpha., which is one degree in the preferred embodiment to provide a radiation field of ##EQU1## degrees on either side of a center of the radiation field. The source and detector assemblies are positioned prior to the first orbit such that the field center is offset a distance D from a center of orbit lying in the orbital plane. The source and detector assemblies are mounted for rotation through a rotation angle .phi..sub.j about an orbital source axis which passes through the source assembly at a distance d from the center of orbit. While maintaining the offset distance D, the assemblies orbit the patient, and radiation intensity data is collected at predetermined angles .gamma..sub.j of orbit. In one embodiment for doubling the effective field size of the patient scanned, the source and detector assemblies are rotated about the source axis to provide the distance D. From an initial position on the center of orbit, the assemblies are rotated by an offset angle ##EQU2## degrees where R is the number of total orbits selected to constitute a complete study. In another embodiment for single field exposure the source and detector assemblies are rotated by the offset angle .phi. defined substantially by the equation ##EQU3## degrees, where 'b' is zero for an odd number N of detectors and is one for an even number N of detectors. For multiorbit studies, the assemblies are rotated between orbits by an amount ##EQU4## degrees depending on the study.