Radiation imaging apparatus, radiation imaging method, body movement measuring method, and body movement measuring program

Patent metadata

Field	Value
Publication number	US-9541509-B2
Application number	US-201113637553-A
Country	US
Kind code	B2
Filing date	Mar 28, 2011
Priority date	Mar 26, 2010
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

A radiation detector is moved along a predetermined axis of movement. Radiation which has passed through a subject is irradiated onto the radiation detector each time the position of the radiation detector changes due to the movement. Signals are read out from the radiation detector each time that radiation is irradiated, to obtain a plurality of radiation images of the subject. Mechanical errors of the radiation detector are detected at each imaging operation, and mechanical error corrected images in which the mechanical errors are corrected are obtained. Amounts of shift of the subject among the mechanical error corrected images are detected, and amounts of movement of the subject during imaging operations are detected based on the amounts of shift.

First claim

The invention claimed is:

1. A radiation imaging apparatus, comprising:
an imaging means for irradiating radiation;
a radiation detector for detecting the radiation of a subject positioned between the irradiating radiation and the radiation detector; and
a moving means for moving the imaging means and/or the radiation detector;
the radiation imaging apparatus being configured to perform a plurality of imaging operations of a subject by moving the imaging means and/or the radiation detector; and the radiation imaging apparatus further comprising:
image obtaining means for reading out signals from the radiation detector each time the radiation detector is moved and the radiation is irradiated, to obtain a plurality of images of the subject;
a mechanical error detecting means for detecting mechanical errors of the imaging means and/or the radiation detector; and
body movement obtaining means for obtaining the amounts of body movement of the subject during the imaging operations, based on the mechanical errors obtained by the mechanical error detecting means,

wherein the radiation imaging apparatus moves the radiation detector, irradiates radiation which has passed through the subject onto the radiation detector each time that the position of the radiation detector changes by being moved, and obtains a plurality of radiation images, at least portions thereof being overlapped,
wherein the imaging means moves the radiation detector along a predetermined axis of movement and irradiates radiation which has passed through the subject onto the radiation detector each time that the position of the radiation detector changes due to the movement and
wherein the radiation imaging apparatus further comprises:
a mechanical error correcting means for correcting the mechanical errors in the plurality of radiation images, to obtain mechanical error corrected radiation images; and
a shift detecting means, for detecting amounts of shift in the subject among the mechanical error corrected radiation images, and

wherein the body movement obtaining means obtains the amounts of body movement of the subject during the imaging operations, based on the amounts of shift,
wherein mechanical error includes inclinations of an imaging surface.

2. A radiation imaging apparatus as defined in claim 1 , further comprising:
display means for displaying the amounts of body movement.

3. A radiation imaging apparatus as defined in claim 1 , further comprising:
a body movement correcting means for correcting the shifts of the subject among the mechanical error corrected radiation images based on the amounts of body movement, to obtain body movement corrected radiation images; and
an image combining means for generating body movement corrected combined images, which are the body movement corrected radiation images combined with each other; and
the display means being a means for displaying the body movement corrected combined images.

4. A radiation imaging apparatus as defined in claim 3 , wherein:
the image combining means generates the body movement corrected combined images such that the degree of positional alignment can be visually confirmed at the portions of the body movement corrected images at which a plurality of the body movement corrected images overlap.

5. A radiation imaging apparatus as defined in claim 3 , wherein:
the image combining means further generates mechanical error corrected combined images, which are the mechanical error corrected radiation images combined with each other; and
the display means switchably displays the body movement corrected combined images and the mechanical error corrected combined images.

6. A radiation imaging apparatus as defined in claim 1 , further comprising:
warning means for issuing a warning in the case that the amounts of body movement exceed a predetermined threshold value.

7. A radiation imaging apparatus as defined in claim 6 , wherein:
the imaging means ceases irradiation of the radiation onto the subject in the case that a warning is issued by the warning means.

8. A radiation imaging apparatus as defined in claim 1 , wherein:
the mechanical errors is at least one of: inclination of an imaging surface, displacement of the imaging surface from a predetermined position, relative shifting among the plurality of radiation images, and displacement of a subject surface, which is a reference surface of the subject, and the imaging surface in a direction parallel thereto.

9. A radiation imaging apparatus, comprising:
a radiation source for emitting radiation;
a radiation detecting means for detecting the radiation of a subject positioned between the emitting radiation and the radiation detecting means; and
a moving means for moving the radiation source and/or the radiation detector;
the radiation source and/or the radiation detector being moved to perform a plurality of imaging operations of a subject; and further comprising:
an imaging system actual movement calculating means, for moving the radiation source and/or the radiation detecting means according to a predetermined pattern, performing a plurality of imaging operations of a reference subject placed at a known position, and for calculating the actual amounts of movement of the radiation source and/or the radiation detecting means based on the projected position of the reference subject within each image obtained by the plurality of imaging operations;
a subject movement specifying means, for specifying the amounts of movement of the subject within a plurality of images, which are obtained by moving the radiation source and/or the radiation detecting means according to the predetermined pattern and performing a plurality of imaging operations;
an estimated subject movement calculating means, for calculating estimated amounts of movement of the subject within a plurality of images which are obtained by moving the radiation source and/or the radiation detecting means according to the predetermined pattern for the actual amounts of movement and performing a plurality of imaging operations; and
a body movement evaluation value calculating means, for calculating a body movement evaluation value that indicates the degree of body movement of the subject, based on a difference between the amounts of movement of the subject and the estimated amounts of movement of the subject,

a warning being displayed or imagining operations being ceased when the body movement evaluation value exceeds a predetermined threshold value.

10. A radiation imaging apparatus as defined in claim 1 , further comprising:
display means for displaying the amounts of body movement;
a body movement correcting means for correcting the shifts of the subject among the mechanical error corrected radiation images based on the amounts of body movement, to obtain body movement corrected radiation images; and
an image combining means for generating body movement corrected combined images, which are the body movement corrected radiation images combined with each other; and
the display means being a means for displaying the body movement corrected combined images.

11. A radiation imaging apparatus as defined in claim 1 , further comprising:
display means for displaying the amounts of body movement; and
warning means for issuing a warning in the case that the amounts of body movement exceed a predetermined threshold value.

12. A radiation imaging apparatus as defined in claim 1 , further comprising:
display means for displaying the amounts of body movement,
wherein the mechanical errors is at least one of: inclination of an imaging surface, displacement of the imaging surface from a predetermined posi

Assignees

• Akahori Sadato
• Yamaguchi Yoshitaka
• Fujifilm Corp

Inventors

• Akahori Sadato
• Yamaguchi Yoshitaka

Classifications

• A61B6/5264

  due to motion · CPC title

• A61B6/4452

  the source unit and the detector unit being able to move relative to each other · CPC title

• A61B6/025

  Tomosynthesis · CPC title

• G01N23/04 Primary

  and forming images of the material · CPC title

• A61B6/584

  determining position of components of the apparatus or device using images of the phantom · CPC title