X-ray imaging apparatus, X-ray imaging method, and X-ray imaging program
AssigneeCanon Kabushiki Kaisha
InventorsChidane Ouchi, Kentaro Nagai, Toru Den, Hidenosuke Itoh
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Abstract
An X-ray imaging apparatus includes a phase grating, an absorption grating, a detector, and an arithmetic unit. The arithmetic unit executes a Fourier transform step of performing Fourier transform for an intensity distribution of a Moiré acquired by the detector, and acquiring a spatial frequency spectrum. Also, the arithmetic unit executes a phase retrieval step of separating a spectrum corresponding to a carrier frequency from a spatial frequency spectrum acquired in the Fourier transform step, performing inverse Fourier transform for the separated spectrum, and acquiring a differential phase image.
Claims19
An X-ray imaging apparatus comprising:
- an X-ray source;
- a phase grating that transmits X-rays from the X-ray source and forms an interference intensity distribution by a Talbot effect;
- an absorption grating that partly shields the interference intensity distribution formed by the phase grating and generates a Moiré;
- a detector that detects an intensity distribution of the Moiré generated by the absorption grating;
- and
- an arithmetic unit that images information of a subject from the intensity distribution of the Moiré detected by the detector and outputs the information,
- wherein the arithmetic unit executes a process including
- a Fourier transform step of performing Fourier transform for the intensity distribution of the Moiré acquired by the detector and acquiring a spatial frequency spectrum, and
- a phase retrieval step of separating a spectrum corresponding to a carrier frequency from the spatial frequency spectrum acquired in the Fourier transform step, performing inverse Fourier transform for the separated spectrum, and acquiring a differential phase image.
An X-ray imaging method used in an X-ray imaging apparatus, the method comprising:
- a step of causing X-rays to be transmitted and forming an interference intensity distribution by a Talbot effect;
- a step of partly shielding the interference intensity distribution and generating a Moiré;
- a step of detecting an intensity distribution of the Moiré;
- a step of performing the Fourier transform for the intensity distribution of the Moiré and acquiring a spatial frequency spectrum;
- a step of separating a spectrum corresponding to a carrier frequency from the spatial frequency spectrum, performing inverse Fourier transform for the separated spectrum, and acquiring a differential phase image;
- and
- a step of integrating the differential phase image and acquiring phase image.
A non-transitory computer-readable medium storing thereon a program that when executed on a computer causes an X-ray imaging apparatus to execute a process comprising:
- a step of causing X-rays to be transmitted and forming an interference intensity distribution by a Talbot effect;
- a step of partly shielding the interference intensity distribution and generating a Moiré;
- a step of detecting an intensity distribution of the Moiré;
- a step of performing the Fourier transform for the intensity distribution of the Moiré and acquiring a spatial frequency spectrum;
- a step of separating a spectrum corresponding to a carrier frequency from the spatial frequency spectrum, performing inverse Fourier transform for the separated spectrum, and acquiring a differential phase image;
- and
- a step of integrating the differential phase image and acquiring a phase image.
An X-ray imaging apparatus comprising:
- an X-ray source;
- a phase grating that transmits X-rays from the X-ray source for forming an interference intensity distribution by a Talbot effect;
- an absorption grating that partly shields bright sections of the interference intensity distribution formed by the phase grating for generating a Moiré;
- a detector that detects information of an intensity distribution of the Moiré generated by the absorption grating;
- and
- an arithmetic unit that calculates information of a differential phase image of a subject based on a detection result by the detector,
- wherein the arithmetic unit executes a process including
- a step of performing Fourier transform for the information of the intensity distribution of the Moiré detected by the detector for acquiring a spatial frequency spectrum of the intensity distribution of the Moiré, and
- a step of using a peak resulted from a period of the Moiré, in the spatial frequency spectrum of the intensity distribution of the Moiré acquired by the Fourier transform, so that the information of the differential phase image of the subject is acquired.
An X-ray imaging method used in an X-ray imaging apparatus, the method comprising:
- a step of causing X-rays to be transmitted for forming an interference intensity distribution by a Talbot effect;
- a step of partly shielding bright sections of the interference intensity distribution for generating a Moiré;
- a step of detecting information of an intensity distribution of the Moiré;
- a step of performing the Fourier transform for the information of the intensity distribution of the Moiré for acquiring a spatial frequency spectrum of the intensity distribution of the Moiré;
- and
- a step of using a peak resulted from a period of the Moiré, in the spatial frequency spectrum of the intensity distribution of the Moiré, so that the information of a differential phase image of a subject is acquired.
A non-transitory computer-readable medium storing thereon a program that when executed on a computer causes an X-ray imaging apparatus to execute a process comprising:
- a step of causing X-rays to be transmitted for forming an interference intensity distribution by a Talbot effect;
- a step of partly shielding bright sections of the interference intensity distribution for generating a Moiré;
- a step of detecting information of an intensity distribution of the Moiré;
- a step of performing the Fourier transform for the information of the intensity distribution of the Moiré for acquiring a spatial frequency spectrum of the intensity distribution of the Moiré;
- and
- a step of using a peak resulted from a period of the Moiré, in the spatial frequency spectrum of the intensity distribution of the Moiré, so that the information of a differential phase image of a subject is acquired.
Dependencies are inferred from the claim text.