X-RAY CT APPARATUS AND X-RAY RADIOGRAPHIC METHOD

• US 20070053478A1
• Filed: 08/28/2006
• Published: 03/08/2007
• Est. Priority Date: 08/31/2005
• Status: Active Grant

• Current Assignee: Toshiba Medical Systems Corporation (Canon Inc.)
• Original Assignee: Toshiba Medical Systems Corporation (Canon Inc.), Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tanaka, Toyoaki, Tsuyuki, Masaharu
• Granted Patent: US 7,881,423 B2
• Time in Patent Office: Days
• US Class Current: 378/4
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/5235 combining images from the same or different ionising radiation imaging techniques, e.g. PET and CT

Abstract

An X-ray CT apparatus is adapted for switchover between a CT mode to obtain a tomographic image of a subject and a transmission mode to obtain a transmission image of the subject, depending upon projection data acquired in an imager system thereof. The apparatus includes an image-data storage device that stores image data of the subject in a three-dimensional region, a three-dimensional image processor that performs a three-dimensional image processing on the image data and generates three-dimensional image data, for display, corresponding to a line-of-sight direction inputted from an input device, and a transmission-image generator that generates the transmission image as to the image-taking direction, from data acquired in the imager system aligned by the CPU.

Claims

1. An X-ray CT apparatus adapted for switchover between a CT mode to obtain a tomographic image of a subject and a transmission mode to obtain a transmission image of the subject,

depending upon projection data acquired in an imager system thereof, the apparatus comprising:

an image-data storage device that stores image data of the subject in a three-dimensional region;

a three-dimensional image processor that performs a three-dimensional image processing on the image data and generates three-dimensional image data, for display, corresponding to a line-of-sight direction inputted;

a drive control that aligns the imager system depending upon an image-taking direction corresponding to the line-of-sight direction; and

a transmission-image generator that generates the transmission image as to the image-taking direction, from data acquired in the imager system aligned by the drive control.

2. An X-ray CT apparatus according to claim 1, further including an input device that establishes a position of the imager system and inputs the position as the image-taking direction to the drive control.

3. An X-ray CT apparatus according to claim 1, further including an input device that inputs a predetermined portion of the three-dimensional image, and a line-of-sight-direction operator that operates a line-of-sight direction to display the predetermined portion with magnification, thereby inputting the line-of-sight direction to the drive control.

4. An X-ray CT apparatus according to claim 1, further including a display control that causes to display, as a three-dimensional image, three-dimensional image data for display in the image-taking direction, and a monitor that displays the three dimensional image.

5. An X-ray CT apparatus according to claim 1, further including a display control that causes to display the transmission image and a monitor that displays the transmission image.

6. An X-ray CT apparatus adapted for switchover between a CT mode to obtain a tomographic image of a subject and a transmission mode to obtain a transmission image of the subject, depending upon projection data acquired in an imager system thereof, the apparatus comprising:

an input device that inputs a tilt angle of a gantry and a tube position of an X-ray tube;

a drive control that changes the tilt angle of the gantry and the tube position of the X-ray tube depending upon the tilt angle and tube position inputted by the input device;

an image-data storage device that stores image data of the subject in a three-dimensional region;

a three-dimensional image processor that determines an image-taking direction depending upon the tilt angle and the tube position, performs a three-dimensional image processing on the image data and generates three-dimensional image data, for display, in a line-of-sight direction corresponding to the image-taking direction; and

a transmission-image generator that generates the transmission image as to the image-taking direction, from data acquired in the imager system aligned by the drive control.

7. An X-ray CT apparatus according to claim 6, wherein the input device is to input at least one of height, widthwise and longitudinal positions of a couch plate, the drive control being to determine a line-of-sight direction for the three-dimensional image processing depending upon at least one of the height, widthwise and longitudinal positions of the couch plate inputted by the input device.

8. An X-ray CT apparatus according to claim 6, wherein the three-dimensional image processor and the drive control are to make a generation process of three-dimensional image data and to change the tilt angle and the tube position, in conjunction of an input to the input device.

9. An X-ray radiographic method adapted for switchover between a CT mode to obtain a tomographic image of a subject and a transmission mode to obtain a transmission image of the subject, depending upon data acquired in an imager system thereof, the method comprising:

an image-data storing step that stores image data of the subject in a three-dimensional region;

a three-dimensional image processing step that performs a three-dimensional image processing on the image data and generates three-dimensional image data, for display, corresponding to a line-of-sight direction inputted;

a drive control step that aligns the imager system depending upon an image-taking direction corresponding to the line-of-sight direction; and

a transmission-image generating step that generates the transmission image as to the image-taking direction, from data acquired in the imager system aligned by the drive control.

10. An X-ray radiographic method according to claim 9, wherein a position of the imager system is established which position is inputted as the image-taking direction, thereby effecting the drive control step.

11. An X-ray radiographic method according to claim 9, further including a line-of-sight direction operating step that, when established a predetermined portion of the three-dimensional image, operated is a line-of-sight direction to display the predetermined portion with magnification, whereby the drive control step is effected by inputting the line-of-sight direction.

12. An X-ray radiographic method according to claim 9, wherein the three-dimensional image processing uses at least one of volume rendering process, surface rendering process, MPR (multi planar reconstruction) process, CVR (computed volume radiography) process and MIP (minimum intensity projection) process.

13. An X-ray radiographic method according to claim 9, wherein at least one of a tube position of an X-ray tube, a tilt angle of a gantry and a position of a couch plate is used as a position of the imager system.

14. An X-ray radiographic method according to claim 9, further including a three-dimensional image display step that displays, as a three-dimensional image, three-dimensional image data, for display, as to the line-of-sight direction.

15. An X-ray radiographic method according to claim 14, wherein a virtual opening degree of a collimator of the imager system is regulated on a three-dimensional image displayed in the three-dimensional image display step, the opening degree of the collimator of the imager system being inputted according to the virtual opening degree after regulated to effect the drive control step.

16. An X-ray radiographic method according to claim 14, wherein the three-dimensional image processing step is to properly generate three-dimensional image data, for display, corresponding to a post-change line-of-sight direction in conjunction with a change of a line-of-sight direction done on a screen for establishing a position of the imager system.

17. An X-ray radiographic method according to claim 16, wherein the position of the imager system is established based on a numeral representative of a position of the imager system, on the screen.

18. An X-ray radiographic method according to claim 14, wherein the three-dimensional image processing step is to properly generate three-dimensional image data, for display, corresponding to a post-change line-of-sight direction in conjunction with a change of a line-of-sight direction done on a screen of a three-dimensional image displayed in the three-dimensional image display step.

19. An X-ray radiographic method according to claim 18, wherein the line-of-sight direction is restricted not to establish an image-taking direction where a transmission image cannot be acquired in the imager system.

20. An X-ray radiographic method according to claim 14, wherein the three-dimensional image processing step is to determine a line-of-sight direction for taking an image of a sectional plane orthogonal to a direction designated by using the three-dimensional image, on a screen of a three-dimensional image displayed in the three-dimensional image display step, and to generate three-dimensional image data, for display, corresponding to the line-of-sight direction.

21. An X-ray radiographic method according to claim 20, wherein the direction designated is taken as a blood-vessel extending direction.

22. An X-ray radiographic method according to claim 9, further including a transmission-image display step that displays the transmission image.