Radiation image processing apparatus, radiation image processing method, program, and computer-readable medium

• US 20050111614A1
• Filed: 10/22/2004
• Published: 05/26/2005
• Est. Priority Date: 11/05/2003
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Matsuura, Tomohiko
• Granted Patent: US 7,327,823 B2
• Time in Patent Office: Days
• US Class Current: 378/19
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4085 Cone-beams
• CPC Class Codes: A61B 6/488 involving pre-scan acquisition
• CPC Class Codes: A61B 6/5217 extracting a diagnostic or physiological parameter from medical diagnostic data
• CPC Class Codes: A61B 6/5264 due to motion
• CPC Class Codes: A61B 6/583 using calibration phantoms
• CPC Class Codes: G06T 11/005 Specific pre-processing for tomographic reconstruction, e.g. calibration, source positioning, rebinning, scatter correction, retrospective gating
• CPC Class Codes: G06T 2211/412 Dynamic
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment
• CPC Class Codes: Y10S 378/901 Computer tomography program or processor

Abstract

In a radiation image processing apparatus and method, body movement information of a subject to be inspected is extracted during CT scanning. It is then determined whether or not a repeat radiograph is required based on the body movement information of the subject. If it is determined that a repeat radiograph is not required, a CT image is reconstructed from projection images. If it is determined that a repeat radiograph is required, the need for a repeat radiograph is instructed.

Claims

1. A radiation image processing apparatus for reconstructing a CT image from a plurality of image data items of a subject to be inspected, the image data items taken from different angles, comprising:

body-movement information extracting means for extracting information based on the subject from at least two image data items and calculating at least one change indicating a body movement of the subject based on the information;

repeat-radiograph determination means for determining whether or not a repeat radiograph is required based on the at least one change; and

CT reconstruction means for reconstructing a CT image from the plurality of image data items;

wherein the CT reconstruction means starts reconstructing the CT image when a repeat radiograph is not required.

2. A radiation image processing apparatus according to claim 1, wherein the body-movement information extracting means extracts coordinates of a structure constituting the subject to be inspected from at least two of the image data items and calculates changes in the coordinates of the extracted structure.

3. A radiation image processing apparatus according to claim 1, wherein the body-movement information extracting means extracts a structure constituting the subject to be inspected from at least two of the image data items and calculates an overlap area between two images of the structure as the change.

4. A radiation image processing apparatus according to claim 2, wherein the coordinates of a structure constituting the subject to be inspected are coordinates of an outline of the structure and are normalized.

5. A radiation image processing apparatus according to claims 2 to 4, wherein the structure is one of a diaphragm, a lung area, and the subject to be inspected.

6. A radiation image processing apparatus according to claim 5, wherein the body-movement information extracting means calculates a change based on information extracted from an image data item of a first image and information extracted from an image data item of a second image taken from the reverse angle to the first image.

7. A radiation image processing apparatus according to claim 1, further comprising display means for presenting the change calculated by the body-movement information extracting means to an operator.

8. A radiation image processing apparatus according to claim 7, wherein, in the repeat-radiograph determination means, the operator determines whether or not a repeat radiograph is required based on the change presented by the display means.

9. A radiation image processing apparatus according to claim 1, further comprising an X-ray generation source for emitting radiation to the subject to be inspected, a rotating unit to relatively rotate the subject under the radiation emitted from the X-ray generation source, a two-dimensional X-ray sensor for converting the radiation to electrical signals, and a processing circuit for converting the electrical signals to an image data item, wherein a plurality of the image data items is output from the processing circuit.

10. A radiation image processing method for reconstructing a CT image from a plurality of image data items, the method comprising the steps of:

extracting information based on a subject to be inspected from at least two image data items and calculating at least one change indicating a body movement of the subject based on the information; and

determining whether or not a repeat radiograph is required based on the at least one change calculated in said extracting step.

11. A program for causing a computer to execute a predetermined method, wherein the predetermined method includes the steps of the radiation image processing method according to claim 10.

12. A computer-readable medium for storing the program according to claim 11.