X-ray diaphragm mechanism and X-ray CT apparatus

Patent metadata

Field	Value
Publication number	US-9312038-B2
Application number	US-201214115491-A
Country	US
Kind code	B2
Filing date	May 30, 2012
Priority date	May 31, 2011
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

The present invention includes: X-ray shielding materials; X-ray shielding material mounting plates to which the X-ray shielding portions are fixed; a driven side link and a driving side link that connect the two X-ray shielding material mounting plates to each other so that the X-ray shielding portions face each other and cross each other; connecting portions that connect each of the X-ray shielding material mounting plates to the driven side link and the driving side link; and a driving device that drives the driving side link so as to rotate. Connecting portions and are provided at positions not interfering with a movable region of the X-ray shielding material mounting plates formed in conjunction with the rotational driving of the driven side link and the driving side link. The X-ray shielding material mounting plates are moved by the rotational driving of the driving side link and accordingly, the slit width between the X-ray shielding materials is changed.

First claim

The invention claimed is:

1. An X-ray diaphragm mechanism, comprising:
two X-ray shielding members each including an X-ray shielding portion, which is formed of an X-ray shielding material, a first peripheral portion located on one end side of the X-ray shielding portion in a longitudinal direction, and a second peripheral portion located on the other end side of the X-ray shielding portion in the longitudinal direction;
a first link that connects the first peripheral portions of the X-ray shielding members so that the first peripheral portions cross each other in X-ray incidence direction in a state where the X-ray shielding portions of the X-ray shielding members face each other and a second link that connects the second peripheral portions of the X-ray shielding members so that the second peripheral portions cross each other in the X-ray incidence direction in a state where the X-ray shielding portions of the X-ray shielding members face each other;
a first connecting portion that connects the first peripheral portion of each X-ray shielding member and the first link to each other and a second connecting portion that connects the second peripheral portion of each X-ray shielding member and the second link to each other; and
a driving device that drives the first link or the second link so as to rotate,
wherein a slit width between the X-ray shielding portions of the two X-ray shielding members is changed by moving the two X-ray shielding members in conjunction with rotational driving of the first and second links, and the first and second connecting portions are provided at positions not interfering with a movable region of the X-ray shielding member.

2. The X-ray diaphragm mechanism according to claim 1 ,
wherein each of the first and second connecting portions includes a height adjustment member, and
the height adjustment member is disposed between the first peripheral portion of one of the two X-ray shielding members and the first link and between the second peripheral portion of the one X-ray shielding member and the second link, and supports the one X-ray shielding member at a different height from the other X-ray shielding member.

3. The X-ray diaphragm mechanism according to claim 1 ,
wherein each of the two X-ray shielding members has an approximately plate-shaped X-ray shielding plate, which is formed of an X-ray shielding material, and an X-ray shielding material mounting plate including a region for fixing the X-ray shielding plate between the first and second peripheral portions.

4. The X-ray diaphragm mechanism according to claim 3 ,
wherein the first and second peripheral portions are disposed so as to bypass each rotation center of the first and second links,
a portion where the first peripheral portions cross each other and a portion where the second peripheral portions cross each other are disposed on a side farther from the X-ray shielding plate than each rotation center of the first and second links, and
each rotation center of the first and second links and the first and second connecting portions are disposed outside a movable region of the X-ray shielding material mounting plate.

5. The X-ray diaphragm mechanism according to claim 3 ,
wherein each of the X-ray shielding material mounting plates includes a flange protruding in an opposite direction to the X-ray shielding plate from each of the first and second peripheral portions, and
the first connecting portion connects the flange protruding from the first peripheral portion and the first link to each other, and the second connecting portion connects the flange protruding from the second peripheral portion and the second link to each other.

6. The X-ray diaphragm mechanism according to claim 3 ,
wherein the first connecting portion includes a connector for connecting the first link and one of the X-ray shielding members to each other, and the other X-ray shielding member includes a clearance groove for avoiding interference with the facing connector in a region where interference with the connector may occur, and
the connector is inserted into the clearance groove at the time of rotational driving of the first and second links.

7. The X-ray diaphragm mechanism according to claim 3 ,
wherein the X-ray shielding plate is fixed to a surface of the one X-ray shielding material mounting plate facing the other X-ray shielding material mounting plate, the X-ray shielding plate is fixed to a surface of the other X-ray shielding material mounting plate facing the one X-ray shielding material mounting plate, and facing surfaces of the two X-ray shielding plates are disposed so as to form the same plane.

8. The X-ray diaphragm mechanism according to claim 1 ,
wherein, in each of the two X-ray shielding members, the X-ray shielding portion and the first and second peripheral portions are integrally formed using an X-ray shielding material,
the first peripheral portion of each X-ray shielding member includes a first arm portion that protrudes obliquely toward a direction away from the X-ray shielding portion with a shaft of the X-ray shielding portion, which is provided in each X-ray shielding member, along the longitudinal direction as a reference,
the second peripheral portion of each X-ray shielding member includes a second arm portion that protrudes toward a direction away from the X-ray shielding portion with a shaft of the X-ray shielding portion, which is provided in each X-ray shielding member, along the longitudinal direction as a reference,
the first arm portion provided in each X-ray shielding member includes a first groove for avoiding interference with the facing X-ray shielding member,
the second arm portion provided in each X-ray shielding member includes a second groove for avoiding interference with the facing X-ray shielding member,
the first connecting portion connects the first arm portion of each X-ray shielding member and the first link to each other in a state where the first arm portions of the two X-ray shielding members are made to cross each other at the first groove provided in each first arm portion, and
the second connecting portion connects the second arm portion of each X-ray shielding member and the second link to each other in a state where the second arm portions of the two X-ray shielding members are made to cross each other at the second groove provided in each second arm portion.

9. The X-ray diaphragm mechanism according to claim 1 , further comprising:
a stop mechanism portion that, when the slit width is increased to be greater than a maximum width, comes in contact with at least one of the two X-ray shielding members to mechanically stop movement of the X-ray shielding member in a direction in which the slit width is increased.

10. An X-ray CT apparatus, comprising:
the X-ray diaphragm mechanism according to claim 1 ;
an X-ray generation unit that generates X-rays;
an X-ray detector that detects the X-rays and outputs an image signal;
a rotation unit that rotates in a state where the X-ray generation unit, the X-ray diaphragm mechanism, and the X-ray detector are mounted; and
an image reconstruction unit that generates a reconstructed image by performing image reconstruction processing on the basis of the image signal,
wherein the X-ray diaphragm mechanism limits an irradiation range of X-rays generated from the X-ray generation unit.

Assignees

• Takagaki Norifumi
• Suzuki Tsutomu
• Mochitate Mikio
• Hitachi Medical Corp

Inventors

• Takagaki Norifumi
• Suzuki Tsutomu
• Mochitate Mikio

Classifications

• A61B6/035

  Mechanical aspects of CT · CPC title

• G21K1/04

  using variable diaphragms, shutters, choppers · CPC title

• A61B6/06 Primary

  Diaphragms · CPC title

• G01N23/046

  using tomography, e.g. computed tomography [CT] · CPC title

• G21K1/046 Primary

  varying the contour of the field, e.g. multileaf collimators · CPC title