Radiation tomograph

Patent metadata

Field	Value
Publication number	US-2020261031-A1
Application number	US-201515776926-A
Country	US
Kind code	A1
Filing date	Nov 19, 2015
Priority date	Nov 19, 2015
Publication date	Aug 20, 2020
Grant date	—

Abstract

A radiation tomograph whereby the acquisition of transmission data and the measurement of annihilation radiation pairs are simultaneously performed by a single detector ring so as to realize both reduction of the manufacturing cost of a PET device and reduction of a burden to a subject. The transmission data, which shows the distribution of annihilation radiation absorption characteristics within a subject, is computed from data relating to annihilation radiation pairs in the vicinity of a surface of the subject. The transmission data can be acquired by detecting a radioactive drug derived from the subject, which makes imaging exclusively for transmission data unnecessary.

First claim

1 - 8 . (canceled)

9 . An information processing apparatus mounted in a radiation tomograph including a detector ring for detecting an annihilation radiation pair derived from a radioactive drug distributed in a subject, the information processing apparatus comprising:
occurrence position specifying means for specifying an occurrence position of annihilation radiation based on a time difference when an annihilation radiation pair enters the detector ring and an incident position of the annihilation radiation pair on the detector ring; data selecting means for selecting data on a pair generated in a vicinity of a surface of the subject from data indicating an occurrence position of radiation specified by the occurrence position specifying means; absorption characteristic distribution computing means for computing absorption characteristic distribution data indicating a distribution of absorption characteristics of annihilation radiation inside the subject by computing a level of decrease of the number of times of detection of one of a pair scattering in a direction of penetrating the subject due to absorption in the subject based on the number of times of detection of radiation scattering in a tangential direction of a curved surface forming the surface of the subject in an annihilation radiation pair derived from the vicinity of the surface of the subject based on selected data; and image generating means for generating an image indicating a radioactive drug distribution in the subject based on data indicating an occurrence position of radiation specified by the occurrence position specifying means, wherein the image generating means generates an image by executing absorption correction based on the absorption characteristic distribution data.

10 . The information processing apparatus according to claim 9 , wherein data selected by the data selecting means is related to an annihilation radiation pair derived from a radioactive drug accumulated in a capillary vessel under a skin of the subject.

11 . The information processing apparatus according to claim 9 , wherein the absorption characteristic distribution computing means operates by computing an absorption rate of radiation by dividing the number of times of detection of a pair scattering in the tangential direction of the curved surface forming the surface of the subject by the number of times of detection of a pair scattering in a direction of penetrating through the subject.

12 . The information processing apparatus according to claim 9 , wherein the data selecting means operates based on data indicating a shape of an outline of the subject acquired in advance.

13 . An information processing apparatus mounted in a radiation tomograph including a detector ring for detecting an annihilation radiation pair derived from a radioactive drug distributed in a subject and a radiation source configured to irradiate radiation from an outside of the subject and disposed inside the detector ring, the information processing apparatus comprising:
occurrence position specifying means for specifying an occurrence position of annihilation radiation based on a time difference when an annihilation radiation pair enters the detector ring and an incident position of the annihilation radiation pair on the detector ring; data selecting means for selecting data on a pair generated by the radiation source from data indicating an occurrence position of radiation specified by the occurrence position specifying means; absorption characteristic distribution computing means for computing absorption characteristic distribution data indicating a distribution of absorption characteristics of annihilation radiation in the subject based on selected data; and image generating means for generating an image indicating a radioactive drug distribution in the subject based on data indicating an occurrence position of radiation specified by the occurrence position specifying means, wherein the image generating means generates an image by executing absorption correction based on the absorption characteristic distribution data.

14 . A program causing a computer to function as each means of the information processing apparatus according to claim 9 .

15 . A radiation imaging apparatus comprising the information processing apparatus according to claim 9 .

16 . The radiation imaging apparatus according to claim 15 , wherein the radiation imaging apparatus is used for head imaging.

Assignees

• Shimadzu Corp

Inventors

• Tsuda Tomoaki
• Kobayashi Tetsuya

Classifications

• G01T1/161 Primary

  Applications in the field of nuclear medicine, e.g. in vivo counting {(apparatus for radiation diagnosis A61B6/00)} · CPC title

• G06T2207/10104

  Positron emission tomography [PET] · CPC title

• G06T2207/30016

  Brain · CPC title

• G06T5/50

  using two or more images, e.g. averaging or subtraction · CPC title

• G06T7/0012 Primary

  Biomedical image inspection · CPC title