Photon counting detector and x-ray computed tomography apparatus

Patent metadata

Field	Value
Publication number	US-11147522-B2
Application number	US-201916424389-A
Country	US
Kind code	B2
Filing date	May 28, 2019
Priority date	Aug 31, 2018
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

According to one embodiment, a photon-counting detector (PCD) includes a plurality of macro-pixels. The plurality of macro-pixels arranged on a semiconductor crystal has a first face and a second face. The first face and the second face are parallel. Each macro-pixel from the plurality of macro-pixels is configured to acquire projection data for generating a reconstructed image. The plurality of macro-pixels each includes at least one large micro-pixel is disposed within the each macro-pixel and at least two small micro-pixels is disposed within the each macro-pixel. Each of the at least two small micro-pixels has a surface area that is less than a surface area of the at least one large micro-pixel.

First claim

What is claimed is:

1. A photon-counting detector for acquiring projection data for generating a reconstructed image, comprising
a plurality of macro-pixels arranged on a semiconductor crystal having a first face and a second face, wherein the first face and the second face are parallel, wherein the plurality of macro-pixels each includes:
at least one large square micro-pixel disposed within the each macro-pixel, and
at least two small square micro-pixels disposed within the each macro-pixel, such that each of the at least two small square micro-pixels has a surface area that is less than a surface area of the at least one large square micro-pixel, wherein each side length of the at least one large square micro-pixel is greater than each side length of the at least two small square micro-pixels by an integer that is greater than 1.

2. The detector according to claim 1 , wherein a half-length of one side of the macro-pixel corresponds to a length of at least one side of the large square micro-pixel, and a half-length of one side of the large square micro-pixel corresponds to a length of at least one side of the small square micro-pixel.

3. The detector according to claim 1 , wherein the at least one large square micro-pixel has a pixel size within 300 to 600 μm.

4. The detector according to claim 1 , wherein the at least two small square micro-pixels each have a pixel size within 150 to 300 μm.

5. The detector according to claim 1 , wherein each macro-pixel includes one large square micro-pixel and twelve small square micro-pixels.

6. The detector according to claim 1 , wherein each macro-pixel includes two large micro-pixels and eight small micro-pixels.

7. The detector according to claim 1 , wherein each macro-pixel includes three large micro-pixels and four small micro-pixels.

8. The detector according to claim 1 , wherein the plurality of macro pixels includes a 16×16 macro-pixel array comprising a total of 256 macro-pixels.

9. The detector according to claim 1 , wherein the surface area of the at least one large square micro-pixel is twice as great as the surface area of each of the at least two small square micro-pixels.

10. The detector according to claim 1 , further comprising: a first set of detector responses corresponding to the at least one large square micro-pixel; and a second set of detector responses corresponding to the at least two small square micro-pixels.

11. The detector according to claim 10 , wherein information obtained from the first set of detector responses corresponding to the at least one large square micro-pixel is used to calibrate the at least two small square micro-pixels in a low-flux scanning environment.

12. The detector according to claim 10 , wherein information obtained from the second set of detector responses corresponding to the at least two small square micro-pixels is used to calibrate the at least one large square micro-pixel in a high-flux scanning environment.

13. The detector according to claim 1 , further comprising a cathode electrode covering the first face, the plurality of macro-pixels covering the second face.

14. An X-ray CT apparatus, comprising: an X-ray tube configured to emit X-rays; and the detector according to claim 1 , configured to detect X-rays that have been emitted from the X-ray tube and have passed through a subject.

15. The detector according to claim 1 , wherein the plurality of macro-pixels each includes:
a large square micro-pixel disposed at a respective center of the respective macro-pixel, and
the at least two small square micro-pixels disposed adjacent each edge of the respective large square micro-pixel.

16. A photon-counting detector, comprising
a plurality of macro-pixels arranged on a semiconductor crystal having a first face and a second face, wherein the first face and the second face are parallel, wherein the plurality of macro-pixels each includes:
a large micro-pixel disposed at a respective center of the respective macro-pixel, and
N small micro-pixels disposed adjacent each edge of the respective large micro-pixel,

wherein each of the N small micro-pixels disposed adjacent each edge of the respective large micro-pixel has a surface area that is less than a surface area of the large micro-pixel.

17. The detector according to claim 16 , wherein N is 4 such that the each respective large micro-pixel is disposed in the respective center portion of each of the plurality of macro-pixels with the twelve small micro-pixels forming a respective periphery around the each respective large micro-pixel.

18. A photon-counting detector for acquiring projection data for generating a reconstructed image, comprising
a plurality of macro-pixels arranged on a semiconductor crystal having a first face and a second face, wherein the first face and the second face are parallel, wherein the plurality of macro-pixels each includes:
a large micro-pixel disposed within the each macro-pixel and at least two small micro-pixels disposed within the each macro-pixel, wherein a half-length of one side of the macro-pixel corresponds to a length of at least one side of the large micro-pixel, and
each of the at least two small micro-pixels having a surface area that is less than a surface area of the large micro-pixel.

19. A photon-counting detector for acquiring projection data for generating a reconstructed image, comprising
a plurality of macro-pixels arranged on a semiconductor crystal having a first face and a second face, wherein the first face and the second face are parallel, and wherein the plurality of macro-pixels each includes:
a large micro-pixel disposed within the each macro-pixel and at least two small micro-pixels disposed within the each macro-pixel, wherein information obtained from detector responses corresponding to the at least one large micro-pixel is used to calibrate the at least two small micro-pixels in a low-flux scanning environment, and
each of the at least two small micro-pixels having a surface area that is less than a surface area of the large micro-pixel.

Assignees

• Canon Medical Systems Corp

Inventors

• Cai Liang
• Zhan Xiaohui
• Zimmerman Kevin Christopher
• Thompson Richard

Classifications

• G01T1/20183

  Arrangements for preventing or correcting crosstalk, e.g. optical or electrical arrangements for correcting crosstalk · CPC title

• A61B6/4035

  the source being combined with a filter or grating · CPC title

• A61B6/482

  involving multiple energy imaging · CPC title

• A61B6/4291

  the detector being combined with a grid or grating · CPC title

• A61B6/4241 Primary

  using energy resolving detectors, e.g. photon counting · CPC title