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US 5,867,553 AGranted
Computed tomography scanner with reduced power x-ray source
AssigneeAnalogic Corporation
InventorsBernard M. Gordon, John Dobbs
Life of this patent
Estimating the term…
Abstract
The disclosed CT scanner includes an X-ray source and an array of X-ray detectors fixed to a reduced geometry disk which is supported for rotation about an isocenter of the disk. The X-ray source is a reduced power source and a beam hardening filter of reduced size is positioned proximal to the X-ray source so the scanner uses a relatively soft X-ray beam. The scanner further includes circuitry for compensating for non-linearities and channel-to-channel variation in the X-ray detectors.
Claims65
A medical computed tomography scanning system, comprising:
- X-ray tomography means including (a) X-ray generating means for generating X-rays so that the X-rays emanate substantially from a focal spot, and (b) X-ray detector means for detecting at least a portion of the X-rays generated by the X-ray generating means and incident on the X-ray detection means during a tomographic scan;
- a support for supporting a patient;
- and
- means for rotating at least the X-ray generating means about a rotation axis defining an isocenter of the system such that at least said X-ray generating means rotates about the support and the focal spot remains substantially at a fixed, predetermined radial distance from the isocenter during a scan;
- wherein the means for generating X-rays is positioned for rotation about said rotation axis such that the focal spot is separated a substantially fixed radial distance from the isocenter by a predetermined amount sufficient to accommodate a patient but less than about 510 mm.
2 more elements
A medical computed tomography system, comprising:
- X-ray tomography means including (a) X-ray generating means for generating X-rays, and (b) X-ray detector means for detecting at least a portion of the X-rays generated by the X-ray generating means and incident on the X-ray detection means during a tomographic scan;
- a support for supporting a patient;
- and
- means for rotating at least the X-ray generating means about a rotation axis such that said X-ray generating means rotates about said support;
- wherein the X-ray generating means includes a source of X-rays operable at a rated power less than 12 kW, but sufficient to perform a 360 degree scan in a time period on the order of two seconds.
2 more elements
A medical computed tomography system, comprising:
- X-ray tomography means including (a) X-ray generating means for generating X-rays, and (b) X-ray detector means for detecting at least a portion of the X-rays generated by the X-ray generating means and incident on the X-ray detection means during a tomographic scan;
- a support for supporting a patient;
- and
- means for rotating at least the X-ray generating means about a rotation axis such that said X-ray generating rotates about said support;
- wherein the X-ray generating means for generating X-rays includes a source of X-rays and a filter so as to pass soft X-rays so that the energy levels of soft X-ray photons generated by said X-ray generating means and incident on the X-ray detector means between about 20 keV and about 50 keV are greater than that provided by a 0.008 inch copper filter and less than unfiltered X-rays generated by said source of X-rays.
2 more elements
A medical computed tomography system, comprising:
- X-ray tomography means including (a) X-ray generating means for generating X-rays, and (b) X-ray detector means for detecting at least a portion of the X-rays generated by the X-ray generating means and incident on the X-ray detection means during a tomographic scan;
- means for rotating at least the X-ray generating means about a rotation axis;
- a support for supporting a patient;
- and
- a beam hardening filter disposed proximal to the X-ray generating means and between the X-ray generating means and the X-ray detector means, the beam hardening filter comprising a sheet of metal providing an X-ray photon filtering characteristic equivalent to that of a sheet of copper less than 0.008 inches thick.
2 more elements
A medical computed tomography system, comprising:
- X-ray tomography means including (a) X-ray generating means for generating X-rays, and (b) X-ray detector means for detecting at least a portion of the X-rays generated by the X-ray generating means and incident on the X-ray detection means during a tomographic scan;
- a support for supporting a patient;
- and
- means for rotating at least the X-ray generating means about a rotation axis such that said X-ray generating means rotates about said support;
- wherein the X-ray generating means includes a source of X-rays operable on the order of 100 mAs per scan.
2 more elements
A method of performing a medical computed tomography scan, comprising:
- supporting a patient;
- and
- during a scan, rotating an X-ray source about a rotation axis such that said X-ray source rotates about the patient and operating the X-ray source at a rate on the on the order of 100 mAs per scan.
A method of performing a medical computed tomography scan, comprising:
- supporting a patient;
- and
- rotating at least an X-ray source having a focal spot about a rotation axis so as to define an isocenter such that (a) at least the X-ray source rotates about the patient and the focal spot remains substantially at a fixed, predetermined radial distance from the isocenter during a scan, and (b) the focal spot is separated a substantially fixed radial distance from the isocenter by a predetermined amount sufficient to accommodate a patient, but less than about 510 mm.
A method of performing a medical computed tomography scan, comprising:
- supporting a patient;
- and
- scanning the patient with an X-ray beam while filter the X-ray beam with a beam hardening filter comprising a sheet of metal providing an X-ray photon filtering characteristic equivalent to that of a sheet of copper less than 0.008 inches thick.
A method of performing a medical computed tomography scan, comprising:
- supporting a patient;
- and
- rotating the X-ray source about a rotation axis such that the X-ray source rotates about the patient, and generates soft X-rays so that the energy levels of soft X-ray photons generated by said X-ray source and incident on an array of X-ray detectors between about 20 keV and about 50 keV are greater than that provided by a 0.008 inch copper filter and less than unfiltered X-rays generated by said source of X-rays.
A method of performing a medical computed tomography scan, comprising:
- supporting a patient;
- and
- rotating at least the X-ray source about a rotation axis such that the X-ray source rotates about the patient and the X-ray source is operated at a rated power less than 12 kW, but sufficient to perform a 360 degree scan in a time period on the order of two seconds.
Dependencies are inferred from the claim text.