X-RAY IMAGING APPARATUS, X-RAY IMAGING METHOD AND METHOD OF CONTROLLING X-RAY IMAGING APPARATUS

• US 20100278304A1
• Filed: 07/12/2010
• Published: 11/04/2010
• Est. Priority Date: 03/12/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Watanabe, Masatoshi, Takada, Kazuhiro, Mukaide, Taihei
• Granted Patent: US 8,036,336 B2
• Time in Patent Office: Days
• US Class Current: 378/53
• CPC Class Codes: A61B 6/484 involving phase contrast X-ray imaging
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: G01N 23/083 the radiation being X-rays
• CPC Class Codes: G01N 23/20 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
• CPC Class Codes: G21K 1/10 Scattering devices; Absorbing devices; Ionising radiation filters
• CPC Class Codes: G21K 2207/005 Methods and devices obtaining contrast from non-absorbing interaction of the radiation with matter, e.g. phase contrast

Abstract

A simplified X-ray imaging apparatus is capable of computationally determining effective atomic numbers with small error factors even for light elements. The X-ray imaging apparatus has an X-ray generation unit 101 (400) for generating X-rays and a detector 105 (405) for detecting X-rays transmitted through an object of examination 104 (403). A computing unit 106 (406) computationally determines a quantity of an X-ray phase attributable to the object of examination and an X-ray transmittance of the object of examination from data detected by the detector. The computing unit also computationally determines an effective atomic number of the object of examination from ρ_et determined from the quantity of the X-ray phase and μt it determined from the X-ray transmittance.

Claims

1. An X-ray apparatus comprising:

an X-ray generation unit for generating X-rays;

a detector for detecting X-rays emitted from the X-ray generation unit and transmitted through an object of examination; and

a computing unit for computationally determining a phase of the X-rays transmitted through the object of examination and an X-ray transmittance of the object of examination from data obtained by the detector and further computationally determining a characteristic value of the object of examination from the phase of the X-rays and the X-ray transmittance.

2. The X-ray apparatus according to claim 1, wherein the characteristic value of the object of examination is an effective atomic number.

3. The X-ray apparatus according to claim 1, wherein a dividing unit is provided between the X-ray generation unit and the detector.

4. The X-ray apparatus according to claim 3, further comprising:

a moving mechanism for synchronously moving the X-ray generation unit, the dividing element and the detector.

5. A computation method comprising:

a step of detecting X-rays transmitted through an object of examination; and

a step of computationally determining a phase of the X-rays transmitted through the object of examination and an X-ray transmittance of the object of examination from data obtained in the detecting step and further computationally determining a characteristic value of the object of examination from the phase of the X-rays and the X-ray transmittance.

6. The computation method according to claim 5, wherein the characteristic value of the object of examination is an effective atomic number.

7. The computation method according to claim 6, wherein the phase of the X-rays is obtained by using an X-ray dividing element for spatially dividing X-rays.

8. The computation method according to claim 6, wherein the phase of the X-rays is obtained from a refraction angle of X-ray obtained by using an analyzer crystal.