X-ray imaging apparatus and X-ray imaging method

• US 8,532,257 B2
• Filed: 11/29/2010
• Issued: 09/10/2013
• Est. Priority Date: 12/04/2009
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Mukaide, Taihei, Fukuda, Kazunori, Watanabe, Masatoshi, Takada, Kazuhiro, Noma, Takashi
• Primary Examiner(s): THOMAS, COURTNEY D
• Application Number:
  US13/058,889
• Publication Number:
  US 20110194674A1
• Time in Patent Office: 1,016 Days
• Field of Search: 378/62, 378/147, 378/149, 378/156, 378/98.8
• US Class Current: 378/62
• CPC Class Codes: A61B 6/06 Diaphragms
• 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]

Abstract

An X-ray imaging apparatus and an X-ray imaging method can alleviate the influence of scattered X-rays relative to the obtained image. A differential phase contrast image or a phase contrast image of a detection object is computed by using a splitting element and an exposure control unit that synchronizes the X-ray scanning speed and the image acquisition speed of a detecting unit.

Claims

1. An X-ray imaging apparatus comprising:

an X-ray generating unit for generating pulse-shaped X-rays;

a splitting element that spatially splits X-rays generated by said X-ray generating unit;

a detecting unit that detects intensity of each of the split X-rays split by said splitting element and transmitted through a detection object;

a transport unit that moves said X-ray generating unit, said splitting element, the detection object or said detecting unit; and

a transport control unit that controls a scanning time of the X-rays irradiated onto the detection object by means of said transport unit,

wherein said detecting unit comprises a time delay integration type detecting unit which has a plurality of pixel areas and is so arranged that each of the split X-rays split by said splitting element is discretely irradiated over two or more than two pixel areas of said detecting unit, and

wherein said X-ray generating unit and said detecting unit operate with a cycle period of X-ray pulse generation and with a cycle period of electric charge transfer, respectively, and wherein those periods are synchronized such that X-rays are irradiated onto the detection object between timing T0 and timing T1 and X-rays are not irradiated onto the detection object between timing T1 and timing T2 while electric charge transfer is performed in said detecting unit at the timings T0, T1 and T2.

2. The apparatus according to claim 1, wherein a first part of said plurality of pixel areas transfer an electric charge generated only by an intensity of X-rays in that first part of said plurality of pixel areas, and at least a second part of said pixel areas other than said first part of said pixel areas transfer an electric charge generated only by an intensity of X-rays in said second pixel areas.

3. The apparatus according to claim 1, wherein said detecting unit independently detects an intensity of X-rays irradiated onto a single pixel area of said detecting unit and an intensity of X-rays irradiated onto a pixel area or pixel areas adjacent to said single pixel area.

4. The apparatus according to claim 1, wherein the scanning direction of X-rays irradiated onto the detection object is the same as the direction of electric charge transfer in said detecting unit.

5. The apparatus according to claim 1, wherein said splitting element spatially splits X-rays with respect to two directions.

6. The apparatus according to claim 1, wherein said splitting element spatially splits X-rays in a first direction perpendicular to the optical axis direction of the X-rays and in a second direction perpendicular to the optical axis direction of the X-rays and the first direction.

7. The apparatus according to claim 1, further comprising a computing unit that computes a quantity of positional change from information acquired by said detecting unit.

8. The apparatus according to claim 1, further comprising a computing unit that computes a differential phase contrast image or a phase contrast image of the detection object from the information acquired by said detecting unit.

9. The apparatus according to claim 1, further comprising an exposure control unit that synchronizes the scanning time of the X-rays and an image acquisition time of said detecting unit.

10. An X-ray imaging method comprising the steps of:

spatially splitting pulsed-shaped X-rays generated by an X-ray generating unit;

irradiating the spatially split X-rays onto a detection object; and

detecting the intensity of the X-rays transmitted through the detection object by means of a detecting unit, while synchronizing a scanning time of irradiating X-rays onto the detection object and an image acquisition time of the detecting unit,

wherein the detecting unit is a time delay integration type detecting unit which has a plurality of pixel areas and each of the split X-rays is discretely irradiated over two or more than two pixel areas of the detecting unit, and

wherein the X-ray generating unit and the detecting unit operate with a cycle period of X-ray pulse generation and with a cycle period of electric charge transfer, respectively, and wherein those periods are synchronized such that X-rays are irradiated onto the detection object between timing T0 and timing T1 and X-rays are not irradiated onto the detection object between timing T1 and timing T2 while electric charge transfer is performed in the detecting unit at the timings T0, T1 and T2.

11. The method according to claim 10, wherein the detecting unit is a detecting unit for vertically transferring an electric charge of each of the pixels column by column and an electric charge transferring speed of the vertical transfer and a scanning speed of the X-rays are synchronized.

12. The method according to claim 10, wherein a first part of the plurality of pixel areas transfer an electric charge generated only by an intensity of X-rays in that first part of the plurality of pixel areas, and at least a second part of pixel areas that is other than the first part of the plurality of pixel areas transfer an electric charge generated only by an intensity of X-rays in that second part of the pixel areas.

13. The method according to claim 10, wherein the detecting unit independently detects an intensity of X-rays irradiated onto a single pixel area of the detecting unit and an intensity of X-rays irradiated onto a pixel area or pixel areas adjacent to the single pixel area.