Calibration phantom, method, and system
AssigneeElekta Limited
InventorsMarkus Eriksson, Joakim Sebastian da Silva
Life of this patent
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Abstract
Disclosed herein is a calibration phantom for calibrating an imaging scanner. The imaging scanner comprises a rotatable gantry, and a source of imaging radiation and a detector both configured to rotate with the gantry. The calibration phantom comprises a support structure and a plurality of boards, wherein each board comprises a planar calibration pattern formed of radiopaque material. The boards are positioned along a first axis and each board is positioned, by the support structure, at an angle with respect to each of the other boards such that each planar calibration pattern faces a different direction. The directions faced by each planar calibration pattern are substantially perpendicular to the first axis.
Claims24
A calibration phantom for calibrating an imaging scanner, the imaging scanner comprising a rotatable gantry, and a source of imaging radiation and a detector both configured to rotate with the gantry, the calibration phantom comprising:
- a support structure and a plurality of boards, wherein each board comprises a planar calibration pattern formed of radiopaque material, wherein the plurality of boards are positioned along a first axis, wherein each board of the plurality of boards is positioned, by the support structure, at an angle with respect to each of the other boards in the plurality of boards such that each planar calibration pattern faces a different direction, wherein the directions faced by each planar calibration pattern are substantially perpendicular to the first axis.
(canceled)
A method of calibrating an imaging scanner, the imaging scanner comprising a rotatable gantry, and one or more components configured to rotate with the gantry, the one or more components comprising a source of imaging radiation and a detector, the method comprising:
- receiving a plurality of projection images of a phantom positioned within a field of view of the imaging scanner, wherein the projection images are taken from multiple gantry rotation angles, and wherein the phantom comprises a plurality of boards each comprising a calibration pattern formed of radiopaque material, and wherein each board of the plurality of boards is positioned, by a support structure, at an oblique angle to each of the other boards in the plurality of boards such that each planar calibration pattern faces a different direction;
- and
- determining, based on the projection images, at least one calibration parameter, wherein the at least one calibration parameter is indicative of a difference between a nominal position or orientation of a component of the imaging scanner compared to a true position or orientation of the component of the imaging scanner.
(canceled)
(canceled)
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A non-transitory computer-readable medium comprising computer-executable instructions which, when executed by a processor, cause the processor to:
- receive one or more projection images of a phantom positioned within a field of view of an imaging scanner, wherein the one or more projection images are taken from multiple gantry rotation angles, wherein the phantom includes a plurality of boards, wherein each board of the plurality of boards includes a calibration pattern formed of a radiopaque material, wherein each board of the plurality of boards is positioned, by a support structure, at an oblique angle to each of the other boards in the plurality of boards such that each planar calibration pattern faces a different direction;
- and
- determine, based on the one or more projection images, at least one calibration parameter, wherein the at least one calibration parameter is indicative of a difference between a nominal position or nominal orientation of a component the imaging scanner compared to a true position or a true orientation of the component of the imaging scanner.
A system for calibrating an imaging scanner, the imaging scanner comprising a rotatable gantry, and components configured to rotate with the gantry, the components comprising a source of imaging radiation and a detector, the system comprising:
- a phantom comprising a plurality of boards, each board of the plurality of boards comprising a calibration pattern formed of radiopaque material, and each board of the plurality of boards being positioned, by a support structure, at an oblique angle to each of the other boards in the plurality of boards such that each planar calibration pattern faces a different direction;
- and
- a computer-readable medium comprising computer-executable instructions which, when executed by a processor, cause the processor to:
- receive multiple projection images of the phantom taken by the imaging scanner from multiple gantry rotation angles;
- and
- determine at least one calibration parameter based on the multiple projection images, wherein the at least one calibration parameter is indicative of a difference between a nominal position or a nominal orientation of a component of the imaging scanner compared to a true position or a true orientation of the component of the imaging scanner.
Dependencies are inferred from the claim text.