X-ray imager with sparse detector array
AssigneeL-3 Communication Security and Detection Systems, Inc.
InventorsBoris Oreper, Andrew D. Foland
Life of this patent
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Abstract
A system and method for imaging objects with a sparse detector array that includes fewer detectors than conventional x-ray scanning systems. The sparse detector array is positioned to receive x-ray radiation from the at least one x-ray source after passing through an inspection area. The sparse detector array includes a plurality of rows of detector elements, wherein at least some of the plurality of rows are separated by gaps such that the at least some of the plurality of rows are non-contiguous. An iterative reconstruction process is used to determine a volumetric image of the object from the radiation measurements recorded by the detectors in the sparse detector array.
Claims31
An inspection system, comprising:
- an inspection area;
- at least one x-ray source adapted to emit x-ray radiation into the inspection area;
- a sparse detector array positioned to receive x-ray radiation from the at least one x-ray source after passing through the inspection area, wherein the sparse detector array includes a plurality of rows of detector elements, wherein at least some of the plurality of rows are separated by gaps such that the at least some of the plurality of rows are non-contiguous, wherein a percentage of rows in the sparse detector array compared to a full array of detectors is less than 50%;
- and
- at least one processor programmed to:
- determine a first volumetric image of at least a portion of an item within the inspection area using a direct reconstruction process from outputs of the sparse detector array when irradiated by the at least one x-ray source;
- initialize an iterative reconstruction process with the first volumetric image;
- and
- perform the iterative reconstruction process to determine a second volumetric image of at least a portion of the item within the inspection area.
A computer-implemented method for deriving an output volumetric image of an object in an inspection area of an x-ray system, wherein the x-ray system includes a sparse detector array having a plurality of non-contiguous rows of detector elements, wherein a percentage of rows in the sparse detector array compared to a full array of detectors is less than 50%, the method comprising:
- receiving at the detector elements in the sparse detector array, a plurality of radiation measurements indicating amounts of radiation passing through the object from different directions, wherein the plurality of radiation measurements include sparsely-spaced measurements in a fan-beam direction of radiation passing through the object;
- determining a first volumetric image of the object using a direct reconstruction process from the plurality of radiation measurements;
- initializing an iterative reconstruction process with the first volumetric image of the object;
- and
- performing at least one iteration of the iterative reconstruction process from the plurality of radiation measurements to derive the output volumetric image of the object.
An inspection system, comprising:
- at least one x-ray source positioned to emit x-ray radiation toward an inspection area in a tunnel, wherein the tunnel includes a conveyor configured to enable an object placed thereon to pass through the inspection area;
- a sparse detector array positioned to receive the x-ray radiation passing through the object, wherein the sparse detector array includes a plurality of rows of detector elements, wherein the detector elements in each row are oriented along the moving direction of the conveyor, and wherein the sparse detector array includes gaps between at least some of the plurality of rows in a direction perpendicular to the moving direction of the conveyor, wherein a percentage of rows in the sparse detector array compared to a full array of detectors is less than 50%;
- and
- at least one processor programmed to
- determine a first volumetric image of at least a portion of the object using a direct reconstruction process from outputs of the sparse detector array when irradiated by the at least one x-ray source;
- initialize an iterative reconstruction process with the first volumetric image;
- and
- perform the iterative reconstruction process to determine a second volumetric image of at least a portion of the object.
Dependencies are inferred from the claim text.