Method and apparatus of modulating the filtering of radiation during radiographic imaging
AssigneeGeneral Electric Company
InventorsThomas L. Toth, Tsur Bernstein
Life of this patent
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Abstract
The present invention includes a filtering apparatus for a CT imaging system or equivalently for an x-ray imaging system. The filtering apparatus may be translated along a first axis or a transverse axis to with respect to an attenuation pattern of a subject during an imaging session to reduce radiation exposure to anatomical regions of the subject sensitive to radiation exposure and/or regions from which data is not being acquired.
Claims25
A pre-subject filter having variable attenuation in two dimensions for a radiographic imaging system, the filter comprising:
- a first end having a first attenuation profile;
- a second end having a second attenuation profile, the second attenuation profile being larger than the first attenuation profile;
- and
- a body connecting the first end and the second end.
A CT system comprising:
- rotatable gantry having an opening defining a scanning bay;
- a movable table configured to translate a subject to be scanned along a first axis within the scanning bay;
- an x-ray projection source configured to project x-rays projected toward the subject;
- a pre-subject filter to filter x-rays projected toward the subject, the filter having a variable attenuation profile;
- and
- a computer programmed to:
- determine an attenuation pattern of the subject;
- translate the filter along the first axis as a function of the attenuation pattern of the subject;
- and
- acquire imaging data of the subject.
A method of diagnostic imaging comprising the steps of:
- positioning a subject to be scanned into a scanning bay;
- projecting a radiation beam along a beam path toward the subject;
- positioning a filter having variable attenuation in the beam path;
- translating the filter in at least one direction to reduce radiation exposure to sensitive anatomical regions of the subject;
- acquiring imaging data of the subject;
- and
- reconstructing an image of the subject from the imaging data.
A radiographic imaging system comprising:
- a scanning bay;
- a movable table configured to move a subject to be scanned fore and aft along a first direction within the scanning bay;
- an x-ray projection source configured to project x-rays in an x-ray beam toward the subject;
- a pair of cam filters formed of attenuating matter;
- and
- a computer programmed to:
- determine a region-of-interest of the subject;
- and
- position the pair of cam filters to limit x-ray exposure outside the region-of-interest.
A cam filter assembly for use with a radiation emitting imaging system, the cam filter assembly including a pair of cam filters wherein each cam filter has an attenuation power that varies with thickness of the filter, the pair of cam filters being configured to operate in tandem to manipulate a beam of radiation projected toward a subject to limit radiation exposure to a region-of-interest of the subject.
Dependencies are inferred from the claim text.