Method and apparatus for patient-in-place measurement and real-time control of beam-spot position and shape in a scanning electron beam computed tomographic system
AssigneeGE Medical Systems Global Technology Company, LLC
InventorBrian Smyth
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Abstract
A scanning electron beam computed tomographic system is provided with a sub-collimation system that passes X-rays emitted by a beam spot formed by an electron beam that is scanned across an X-ray emitting target, which X-rays would not otherwise reach an object under X-ray examination with the system. The sub-collimation system includes phantom-like objects that cause X-rays to be blocked, or passed, through to X-ray detectors depending primarily upon the beam spot position and, secondarily, on the beam-spot shape. Detector output signals may be used in real-time to control at least one characteristic of the electron beam-spot in a closed-loop correction system.
Claims21
In a scanning electron beam computed tomographic system in which an electron beam is scanned across a target to emit a fan beam of X-rays some of which X-rays may pass through an area defined by a reconstruction radius and having an object therein to be detected by a detector array, a method of controlling at least one characteristic of a beam-spot formed by the scanned said electron beam upon said target, comprising the following steps:
- (a) disposing a sub-collimation system to pass some X-rays emitted by said target when scanned by said electron beam, said sub-collimation system disposed to pass such X-rays as would not otherwise strike said object;
- (b) detecting X-rays passing through said sub-collimation system at different angles such that a detection signal of said X-rays contains information associated with at least one characteristic of said beam-spot selected from a group consisting of (i) timing of said beam-spot along said target, (ii) apparent radius of said beam-spot along said target, and (iii) apparent shape of said beam spot along said target.
For use with a scanning electron beam computed tomographic system in which an electron beam is scanned across a target to emit a fan beam of X-rays some of which X-rays may pass through an area defined by a reconstruction radius and having an object therein to be detected by a detector array, a system to control at least one characteristic of a beam-spot formed by the scanned said electron beam upon said target, the system comprising:
- a sub-collimation system disposed in said computed tomographic system to pass some X-rays emitted by said target when scanned by said electron beam, said sub-collimation system disposed to pass such X-rays as would not otherwise strike said object;
- and
- a detection system to detect X-rays passing through said sub-collimation system at different angles such that a detection signal of said X-rays contains information associated with at least one characteristic of said beam-spot selected from a group consisting of (i) timing of said beam-spot along said target, (ii) apparent radius of said beam-spot along said target, and (iii) apparent shape of said beam spot along said target.
Dependencies are inferred from the claim text.