# US 10,371,649 B2 · Radiation phase change detection method and radiation imaging apparatus

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- Number: US 10,371,649 B2
- Document ID: US10371649B2
- Status: Granted
- Kind: B2
- Application number: 15/491,161
- Filed: 2017-04-19
- Published: 2017-11-02
- Granted: 2019-08-06
- Earliest claimed: 2016-04-28
- Assignees: Canon Kabushiki Kaisha
- Applicants: Canon Kabushiki Kaisha
- Inventors: Nobuhiro Yasui; Yoshihiro Ohashi; Toru Den
- Web page: https://patentgrep.com/patent/US10371649B2

## CPC

- G01N 23/20075: {by measuring interferences of X-rays, e.g. Borrmann effect}
- G01N 23/041: Phase-contrast imaging, e.g. using grating interferometers
- G21K 1/067: {using surface reflection, e.g. grazing incidence mirrors, gratings (multilayer mirrors G21K1/062)}
- G01N 2223/064: interference of radiation, e.g. Borrmann effect
- G01N 2223/505: scintillation
- G21K 2207/005: Methods and devices obtaining contrast from non-absorbing interaction of the radiation with matter, e.g. phase contrast
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- G21K: HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES

## Abstract

A radiation phase change detection method includes: arranging a two-dimensional optical image pickup element, which includes a scintillator, so that, when a period of a self-image generated through a phase grating is defined as D1, and a pixel pitch of the two-dimensional optical image pickup element is defined as D2=kD1, k falls in a range of ½<k≤3/2, and so that interference fringes formed by D1 and D2 depending on a relationship in arrangement of the two-dimensional optical image pickup element with respect to the self-image have a period of 2 times D2 or more and 100 times D2 or less; acquiring images of the interference fringes before and after insertion of an object; and outputting an image on a phase change of the radiation caused by at least the object.

## Claims

### Claim 1

A radiation phase change detection method for detecting a phase change of a radiation, the radiation phase change detection method comprising changing an interference state of the radiation using a phase grating configured to cause interference in the radiation radiated by a radiation source, a scintillator configured to convert the radiation into light, and a two-dimensional optical image pickup element,
wherein the two-dimensional optical image pickup element is incapable of sampling a period of a self-image of the radiation generated through the phase grating, and is capable of sampling interference fringes generated between the period of the self-image and a period of a pixel pitch of the two-dimensional optical image pickup element.

### Claim 2 (depends on 1)

A radiation phase change detection method according to claim 1, further comprising placing an object between the radiation source and the phase grating, or between the phase grating and the scintillator.

### Claim 3 (depends on 1)

A radiation phase change detection method according to claim 1, further comprising arranging the two-dimensional optical image pickup element so that, when the period of the self-image is defined as D1, and the pixel pitch of the two-dimensional optical image pickup element is defined as D2=k*D1, k falls in a range of ½<k≤3/2.

### Claim 4 (depends on 3)

A radiation phase change detection method according to claim 3, further comprising arranging the two-dimensional optical image pickup element so that the interference fringes formed by D1 and D2 have a period of 2 times D2 or more and 100 times D2 or less.

### Claim 5

A radiation phase change detection method for detecting a phase change of a radiation, the radiation phase change detection method comprising:
arranging a two-dimensional optical image pickup element, which includes a scintillator, so that, when a period of a self-image generated through a phase grating is defined as D1, and a pixel pitch of the two-dimensional optical image pickup element is defined as D2=k*D1, k falls in a range of ½<k≤3/2, and so that interference fringes formed by D1 and D2 depending on a relationship in arrangement of the two-dimensional optical image pickup element with respect to the self-image have a period of 2 times D2 or more and 100 times D2 or less;
acquiring a phase change of the interference fringes before and after insertion of an object; and
outputting an image on a phase change of the radiation caused by at least the insertion of the object.

### Claim 6 (depends on 5)

A radiation phase change detection method according to claim 5, further comprising adjusting the relationship in arrangement of the two-dimensional optical image pickup element with respect to the self-image through rotation so that the interference fringes have a period of 100 times D2 or less.

### Claim 7 (depends on 5)

A radiation phase change detection method according to claim 5, wherein the scintillator comprises a scintillator capable of resolving 100 lp/mm at least with a thickness of 150 μm.

### Claim 8 (depends on 5)

A radiation phase change detection method according to claim 5, wherein the scintillator comprises a eutectic phase-separated scintillator, in which a plurality of fiber structures containing GdAlO3 are surrounded by a material containing Al2O3.

### Claim 9 (depends on 5)

A radiation phase change detection method according to claim 5, further comprising arranging a fiber optic plate, which has a periodicity of half the period D1 of the self-image or less, between the scintillator and the two-dimensional optical image pickup element.

### Claim 10

A radiation imaging apparatus, comprising:
a radiation source;
a phase grating configured to cause interference in a radiation radiated by the radiation source;
a scintillator configured to convert the radiation into light; and
a two-dimensional optical image pickup element,
wherein the two-dimensional optical image pickup element is incapable of sampling a period of a self-image of the radiation generated through the phase grating, and is capable of sampling interference fringes generated between the period of the self-image and a period of a pixel pitch of the two-dimensional optical image pickup element.

### Claim 11 (depends on 10)

A radiation imaging apparatus according to claim 10, wherein the two-dimensional optical image pickup element is arranged so that, when the period of the self-image is defined as D1, and the pixel pitch of the two-dimensional optical image pickup element is defined as D2=k*D1, k falls in a range of ½<k≤3/2.

### Claim 12 (depends on 10)

A radiation imaging apparatus according to claim 10, wherein the two-dimensional optical image pickup element is arranged so that the interference fringes formed by D1 and D2 have a period of 2 times D2 or more and 100 times D2 or less.

### Claim 13

A radiation imaging apparatus, comprising:
a radiation source;
a phase grating;
a scintillator; and
a two-dimensional optical image pickup element,
wherein the radiation imaging apparatus is configured to detect a phase change of a radiation by:
arranging the two-dimensional optical image pickup element so that, when a period of a self-image generated through the phase grating is defined as D1, and a pixel pitch of the two-dimensional optical image pickup element, which includes the scintillator, is defined as D2=k*D1, k falls in a range of ½<k≤3/2, and so that interference fringes formed depending on a relationship in arrangement of the two-dimensional optical image pickup element with respect to the self-image have a period of 2 times D2 or more and 100 times D2 or less;
acquiring a phase change of the interference fringes before and after insertion of an object; and
outputting an image on a phase change of the radiation caused by at least the object.

### Claim 14 (depends on 13)

A radiation imaging apparatus according to claim 13, wherein the radiation source comprises an X-ray source.

### Claim 15 (depends on 13)

A radiation imaging apparatus according to claim 13, further comprising at least one selected from the group consisting of a driving system, an arithmetic section, and an image acquisition unit.