Radiological imaging apparatus

• US 20030118155A1
• Filed: 09/25/2002
• Published: 06/26/2003
• Est. Priority Date: 12/26/2001
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Okazaki, Takashi, Kojima, Shinichi, Kitaguchi, Hiroshi, Amemiya, Kensuke, Ueno, Yuuichirou, Umegaki, Kikuo
• Granted Patent: US 6,920,196 B2
• Time in Patent Office: Days
• US Class Current: 378/177
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/4233 using matrix detectors
• CPC Class Codes: A61B 6/5235 combining images from the same or different ionising radiation imaging techniques, e.g. PET and CT
• CPC Class Codes: G01T 1/1644 using an array of optically separate scintillation elements permitting direct location of scintillations G01T1/1645 takes precedence
• CPC Class Codes: G01T 1/249 specially adapted for use in SPECT or PET SPECT imaging G01T1/1642; PET imaging G01T1/2985; detecting prohibited goods, e.g. weapons, explosives, hazardous substances, contraband or smuggled objects G01V5/20

Abstract

An imaging apparatus of a radiological imaging apparatus is provided with a first and a second radiation detectors disposed around a hole portion into which a bed is inserted. The first radiation detector includes a detecting portion formed of GaAs of a square having a side of 5 mm and having a thickness of 2 mm. The second radiation detector includes a detecting portion formed of CdTe of a cube having a side of 5 mm. The first radiation detector detects X-rays emitted from an X-ray source and transmitted through an examinee and does not detect γ-rays emitted from the examinee. The second radiation detector detects above X-rays and γ-rays. An X-ray signal processing apparatus processes an X-ray image signal from the first radiation detector and outputs intensity information thereof. A signal discriminating apparatus processes a γ-ray image signal from the second radiation detector and outputs a pulse signal. Thus, the radiological imaging apparatus capable of carrying out radiation examination of the subject by using X-rays and γ-rays can be simplified.

Claims

1. A radiological imaging apparatus comprising:

a bed on which a subject is laid;

an image pickup apparatus;

the image pickup apparatus comprising;

an X-ray source which is used to irradiate the subject with X-rays;

an X-ray source moving apparatus for moving the X-ray source in a circumferential direction of a hole portion into which the bed is inserted;

a plurality of first radiation detectors, disposed around the hole portion, for not substantially detecting γ

-rays from the subject but detecting X-rays, and outputting a first detecting signal which is a detecting signal of X-rays; and

a second radiation detector, disposed around the hole portion, for detecting γ

-rays and X-rays from the subject and outputting both the first detecting signal and a second detecting signal which is a detecting signal of γ

-rays;

a first signal processing apparatus for processing the first detecting signal outputted from the first radiation detector; and

a second signal processing apparatus for processing the second detecting signal outputted from the second radiation detector.

3. The radiological imaging apparatus according to claim 1 or 2 wherein the X-ray source is moved in a circumferential direction of the hole portion along a line nearer a center of the hole portion than the first radiation detector and the second radiation detector.

4. The radiological imaging apparatus according to claim 3 wherein a plurality of circular rows of radiation detectors including the first radiation detector and the second radiation detector and surrounding the hole portion are disposed in an axial direction of the hole portion.

5. The radiological imaging apparatus according to claim 3 wherein a group of circular radiation detectors are formed by arranging a plurality of circular rows of radiation detectors having pluralities of radiation detectors arranged to surround the hole portion in an axial direction of the hole portion;

and

wherein among the plurality of circular rows of radiation detectors, a portion of the circular rows of radiation detectors includes a plurality of the first radiation detectors only as the radiation detectors and remaining ones of the circular rows of radiation detectors include a plurality of the second radiation detectors only as the radiation detectors.

6. The radiological imaging apparatus according to claim 1 or 2 wherein the X-ray source is moved in the circumferential direction of the hole portion on outer sides of the first radiation detector and the second radiation detector.

7. The radiological imaging apparatus according to claim 6 wherein a group of circular radiation detectors are formed by arranging a plurality of circular rows of radiation detectors having pluralities of radiation detectors arranged to surround the hole portion in an axial direction of the hole portion;

wherein a gap for allowing X-rays emitted from the X-ray source to pass therethrough is defined in the group of rink-like radiation detectors; and

wherein among the plurality of circular rows of radiation detectors, a portion of the circular rows of radiation detectors includes a plurality of the first radiation detectors only as the radiation detectors and disposed contiguously to the gap, and remaining ones of the circular rows of radiation detectors include a plurality of only the second radiation detectors as the radiation detectors.

8. The radiological imaging apparatus according to claim 6 wherein a group of circular radiation detectors is formed by arranging a plurality of circular rows of radiation detectors having pluralities of radiation detectors arranged to surround the hole portion in an axial direction of the hole portion;

wherein a gap for allowing X-rays emitted from the X-ray source to pass therethrough is defined in the group of circular radiation detectors; and

wherein a row of radiation detectors including a plurality of the first radiation detectors only as the radiation detectors in a circumferential direction of the hole portion is disposed on a circular member on which the X-ray source is disposed, opposite to the X-ray source, the first radiation detectors are moved in a circumferential direction of the gap for allowing X-rays to pass therethrough along with movement of the X-ray source and remaining ones of the circular rows of radiation detectors include a plurality of the second radiation detectors only as the radiation detectors.

9. The radiological imaging apparatus according to claim 1 or 2 wherein the first radiation detector is disposed at a position nearer the hole portion than the second radiation detector.

10. The radiological imaging apparatus according to claim 8 wherein the first radiation detector and the second radiation detector are disposed in line in a radial direction of the hole portion.

11. The radiological imaging apparatus according to claim 1 or 2 wherein the radiation detector is a semiconductor radiation detector.

12. The radiological imaging apparatus according to claim 1 or 2, further comprising a tomographic image data forming apparatus for forming data of a first tomographic image of the subject based on first information outputted from the first signal processing apparatus by processing the first detecting signal, forming data of a second tomographic image of the subject based on second information outputted from the second signal processing apparatus by processing the second detecting signal, and forming data of a synthesized tomographic image caused by a combination of the data of the first tomographic image and the data of the second tomographic image.

13. The radiological imaging apparatus according to claim 12 wherein the first tomographic image is an X-ray CT image and the second tomographic image is a CT image.

2. A radiological imaging apparatus comprising:

a bed on which a subject is laid;

an image pickup apparatus;

the image pickup apparatus comprising;

an X-ray source which irradiates the subject with X-rays;

an X-ray source moving apparatus for moving the X-ray source in a circumferential direction of a hole portion into which the bed is inserted;

a plurality of first radiation detectors, disposed around the hole portion, for detecting γ

-rays and X-rays from the subject and outputting both a first detecting signal which is a detecting signal of X-rays and a second detecting signal which is a detecting signal of γ

-rays; and

a second radiation detector, disposed around the hole portion, for detecting γ

-rays and X-rays from the subject and outputting both the first detecting signal and the second detecting signal;

a first signal processing apparatus for processing the first detecting signal outputted from the first radiation detector; and

a second signal processing apparatus for processing the second detecting signal outputted from the second radiation detector.