X-ray computed tomography apparatus and radiation detector

Patent metadata

Field	Value
Publication number	US-9354331-B2
Application number	US-201213614252-A
Country	US
Kind code	B2
Filing date	Sep 13, 2012
Priority date	Jun 14, 2011
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

According to one embodiment, an X-ray computed tomography apparatus includes an X-ray tube, a detector, a first DAS, and a second DAS. The radiation detector includes a plurality of detection elements. Each detection element repeatedly detects X-rays generated by the X-ray tube and transmitted through a subject and repeatedly generates an electrical signal corresponding to the energy of the repeatedly detected X-rays. The first DAS acquires the electrical signal detected by part of the imaging region of each detection element in the integral mode. The second DAS acquires the electrical signal detected by the other part of the imaging region of each detection element in the photon count type mode.

First claim

What is claimed is:

1. An X-ray computed tomography apparatus comprising:
an X-ray tube configured to generate X-rays;
a detector including a plurality of detection elements each configured to detect X-rays generated by the X-ray tube and transmitted through a subject and generate an electrical signal corresponding to an energy of the detected X-rays;
a first acquisition unit configured to acquire the electrical signal detected by part of an imaging region of each of the plurality of detection elements in an integral mode; and
a second acquisition unit configured to acquire the electrical signal detected by the other part of the imaging region of each of the plurality of detection elements in a photon count type mode,
wherein the detector comprises:
a scintillator configured to absorb an energy of X-rays from the X-ray tube and generate scintillation corresponding to the energy of the absorbed X-rays;
a first light receiving element provided in a first section on one surface of the scintillator and configured to generate the electrical signal corresponding to the generated scintillation and supply the electrical signal to the first acquisition unit, and
a second light receiving element provided in a second section other than the first section on the one surface, and the second section not overlapping with the first section in a direction perpendicular to the one surface of the scintillator, and configured to generate the electrical signal corresponding to the generated scintillation and supply the electrical signal to the second acquisition unit, and
the first light receiving element is connected to the first acquisition unit, and the second light receiving element is connected to the second acquisition unit.

2. The X-ray computed tomography apparatus of claim 1 , wherein the first section has an area larger than the second section.

3. The X-ray computed tomography apparatus of claim 1 , wherein a member for attenuating the scintillation is provided between the scintillator and the second light-receiving element.

4. The X-ray computed tomography apparatus of claim 1 , wherein the first acquisition unit generates an integral signal of the electrical signal, and
the second acquisition unit repeatedly specifies an energy range to which the detected X-ray photon belongs among a plurality of preset energy ranges based on the electrical signal, and counts the number of photons in each of the plurality of energy ranges.

5. The X-ray computed tomography apparatus of claim 4 , further comprising:
a correction unit configured to correct the integral signal in accordance with the counted number of photons; and
a reconstruction unit configured to reconstruct an image concerning the subject based on the corrected integral signal.

6. The X-ray computed tomography apparatus of claim 5 , wherein the correction unit multiplies the integral signal by a ratio between the total number of photons counted in the plurality of energy ranges and the number of photons counted in a specific energy range of the plurality of energy ranges.

7. The X-ray computed tomography apparatus of claim 5 , further comprising a display unit configured to display the reconstructed image.

8. The X-ray computed tomography apparatus of claim 5 , further comprising:
a first reconstruction unit configured to reconstruct a first image concerning the subject based on the integral signal; and
a second reconstruction unit configured to reconstruct a second image concerning the subject based on the number of photons in the plurality of energy ranges.

9. The X-ray computed tomography apparatus of claim 1 , wherein the detector also serves as a gamma ray detector configured to detect gamma rays from a radioactive isotope in the subject.

10. A radiation detection apparatus comprising:
a scintillator configured to generate scintillation corresponding to an energy of incident X-rays;
a first light-receiving element provided in a first section on one surface of the scintillator and configured to generate a first electrical signal corresponding to the generated scintillation;
a second light-receiving element provided in a second section other than the first section on the one surface, and the second section not overlapping with the first section in a direction perpendicular to the one surface of the scintillator, and configured to generate a second electrical signal corresponding to the generated scintillation;
a first acquisition unit configured to acquire the first electrical signal generated by the first light receiving element in an integral mode; and
a second acquisition unit configured to acquire the second electrical signal generated by the second light receiving element in a photon count type mode,
wherein the first light receiving element is connected to the first acquisition unit, and the second light receiving element is connected to the second acquisition unit.

11. The radiation detection apparatus of claim 10 , wherein the first section has an area larger than the second section.

12. The radiation detection apparatus of claim 10 , wherein a member for attenuating the scintillation is provided between the scintillator and the second light-receiving element.

Assignees

• Sagoh Tomoe
• Nakayama Michito
• Matsuda Keiji
• Nambu Shuya
• Hashimoto Atsushi
• Kanemaru Takashi
• Toshiba Kk
• Toshiba Medical Sys Corp

Inventors

• Sagoh Tomoe
• Nakayama Michito
• Matsuda Keiji
• Nambu Shuya
• Hashimoto Atsushi
• Kanemaru Takashi

Classifications

• A61B6/032

  Transmission computed tomography [CT] · CPC title

• A61B6/4078

  Fan-beams · CPC title

• G01T1/247 Primary

  Detector read-out circuitry (for processing gain or off-set correction H04N) · CPC title

• G01T1/2008

  using a combination of different types of scintillation detectors, e.g. phoswich · CPC title

• A61B6/4241

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