X-RAY FLUX MANAGEMENT DEVICE
First Claim
Patent Images
1. An x-ray beam chopper for a radiographic imaging apparatus, the chopper comprising:
- a rotatable frame that rotates about an axis that is substantially perpendicular to both a central beam of x-rays emitting from an x-ray source and a patient axis of a CT gantry;
at least one x-ray transmission window disposed in the rotatable frame that allows a generally free transmission of x-rays; and
at least one x-ray filtering window disposed in the rotatable frame that filters x-rays.
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Abstract
The invention is directed to an x-ray flux management device that adaptively attenuates an x-ray beam to limit the incident flux reaching a subject and radiographic detectors in potentially high-flux areas while not affecting the incident flux and detector measurements in low-flux regions. While the invention is particularly well-suited for CT, the invention is also applicable with other x-ray imaging systems. In addition to reducing the required detector system dynamic range, the present invention provides an added advantage of reducing radiation dose.
45 Citations
24 Claims
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1. An x-ray beam chopper for a radiographic imaging apparatus, the chopper comprising:
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a rotatable frame that rotates about an axis that is substantially perpendicular to both a central beam of x-rays emitting from an x-ray source and a patient axis of a CT gantry;
at least one x-ray transmission window disposed in the rotatable frame that allows a generally free transmission of x-rays; and
at least one x-ray filtering window disposed in the rotatable frame that filters x-rays. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A radiographic imaging apparatus comprising:
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an x-ray source;
an x-ray detector;
a segmented filtering assembly having a generally annular frame with at least one low x-ray flux segment and at least one high x-ray flux segment; and
a filtering assembly controller that causes the low x-ray flux segment to be in an x-ray beam path during a low x-ray flux data acquisition view and causes the high x-ray flux segment to be in the x-ray beam path during a high x-ray flux data acquisition view, by rotating the filtering assembly about an axis of rotation that is substantially perpendicular to both a central beam of x-rays emitting from the x-ray source and an axis parallel to an axis of a patient. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24-28. -28. (canceled)
Specification