X-ray diagnostic system preferable to two dimensional x-ray detection

• US 6,196,715 B1
• Filed: 04/27/1998
• Issued: 03/06/2001
• Est. Priority Date: 04/25/1997
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Taguchi, Katsuyuki, Nambu, Kyojiro, Oishi, Satoru
• Primary Examiner(s): Porta, David P.
• Assistant Examiner(s): HOBDEN, PAMELA R
• Application Number:
  US09/066,772
• Time in Patent Office: 1,044 Days
• Field of Search: 378/197, 378/205, 378/98.8, 378/11, 378/14, 378/15, 378/195, 378/196, 378/20
• US Class Current: 378/197
• CPC Class Codes: A61B 6/00 Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment instruments measuring radiation intensity for application in the field of nuclear medicine, e.g. in vivo counting, G01T1/161; apparatus for taking X-ray photographs G03B42/02
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4021 involving movement of the focal spot
• CPC Class Codes: A61B 6/4085 Cone-beams
• CPC Class Codes: A61B 6/4092 for producing synchrotron radiation
• CPC Class Codes: A61B 6/4233 using matrix detectors
• CPC Class Codes: A61B 6/4291 the detector being combined with a grid or grating
• CPC Class Codes: A61B 6/469 for selecting a region of interest [ROI]
• CPC Class Codes: A61B 6/481 involving the use of contrast agents
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• CPC Class Codes: A61B 6/541 involving acquisition triggered by a physiological signal
• CPC Class Codes: G03B 42/02 using X-rays

Abstract

An X-ray tomosynthesis system as an X-ray diagnostic system is provided. The system comprises an X-ray generator irradiating an X-ray toward a subject, and a planar-type X-ray detector detecting the X-ray passing through the subject and outputting two dimensional imaging signals based on the detected X-ray. The system comprises a supporting/moving mechanism supporting at least one of the X-ray generator and the X-ray detector so that the at least one is moved relatively to the subject. The system also comprises an element setting a ROI position of the subject, an element for obtaining a plurality of three dimensional coordinates of pixels included in the ROI, a calculating element obtaining two dimensional coordinates of data in the two dimensional imaging signals for each of the two dimensional imaging signals detected by the X-ray detector, the data being necessary for obtaining pixel values of the three dimensional coordinates; and an element for obtaining the pixel value of each of the three dimensional coordinates by extracting the corresponding data of the two dimensional coordinates from the detected two dimensional imaging signals and adding the extracting data.

Claims

1. An X-ray diagnostic system comprising:

an X-ray generator configured to irradiate an X-ray through a subject to be imaged;

a planar-type X-ray detector configured to receive the X-ray which has passed through the subject and to convert the received X-ray into electric two-dimensional imaging signals;

supporting means for supporting the X-ray detector;

incidence angle adjusting means, arranged between the X-ray detector and the supporting means, for adjusting an incidence angle of the X-ray upon the X-ray detector view by view by rotationally driving the X-ray detector; and

image processing means for producing an X-ray tomogram of the subject by performing image processing on the imaging signals obtained at each view.

2. The system of claim 1, wherein the supporting means comprises:

a C-shaped arm of which a one end supports the X-ray generator and of which an other end angle-adjustably supports the X-ray detector;

an arm holder configured to support the C-shaped arm slidably and rotatably; and

a holder supporting mechanism configured to rotatably support the arm holder.

3. The system of claim 1, wherein the image processing means is constructed to convert, view by view, data from the X-ray that has passed through a trapezoidal region defined by the incidence angle of the X-ray on the X-ray detector into rectangular image data, and to obtain the X-ray tomogram on the basis of the plurality of rectangular image data.

4. The system of claim 3, wherein the supporting means comprises:

a C-shaped arm having one end which supports the X-ray generator and an other end which angle-adjustably supports the X-ray detector;

an arm holder configured to support the C-shaped arm slidably and rotatably; and

a holder supporting mechanism configured to rotatably support the arm holder.

5. The system of claim 1, wherein the supporting means comprises:

a C-shaped arm configured to support the X-ray generator and the X-ray detector at both ends;

sliding/supporting means slidably and rotatably supporting the C-shaped arm; and

rotatably supporting means rotatably supporting the sliding/supporting means,

wherein the incidence angle adjusting means is arranged between the C-shaped arm and the X-ray detector.

6. The system of claim 5, wherein the image processing means is constructed to obtain, view by view, a trapezoidal region through which the X-ray irradiated to the X-ray detector passes on the basis of the incidence angle of the X-ray, to convert, view by view, data from the X-ray that has passed through the trapezoidal region into rectangular image data, and to produce the X-ray tomogram on the basis of the plurality of rectangular image data in relation to each respective view.

8. The X-ray diagnostic system of claim 1, further comprising:

moving means for moving at least one of the X-ray generator and the X-ray detector so that a spatial position of the at least one of the X-ray generator and the X-ray detector is changed relatively to the subject, view by view; and

means for obtaining a relative positional relationship between the X-ray generator and the X-ray detector for each view,

wherein the image processing means includes;

means for setting a three-dimensional ROI that includes the subject;

means for obtaining a plurality of three-dimensional coordinates of pixels included in the ROI; and

means for obtaining, as data of the X-ray tomogram, a pixel value of each of the three-dimensional coordinates on the basis of the two-dimensional imaging signals detected view by view and the relative positional relationship obtained view by view.

9. The X-ray diagnostic system of claim 8, wherein the three-dimensional coordinate pixel value obtaining means comprises:

means for obtaining, view by view, two-dimensional coordinates of signals selected from the two-dimensional imaging signals; and

means for producing the pixel values of the three-dimensional coordinates by extracting, view by view, the corresponding signals of the two-dimensional coordinates from the detected two-dimensional imaging signals and adding the extracted data of each view to each other.

10. The system of claim 9, wherein the setting means is constructed to set, as the ROI, a planar cross section of the subject, of which inclination relative to the subject is changeable.

11. The system of claim 9, wherein the setting means is constructed to set, as the ROI, a curved cross section of the subject.

14. The X-ray diagnostic system of claim 1, further comprising:

moving means for moving at least one of the X-ray generator and the X-ray detector so that a spatial position of the at least one of the X-ray generator and the X-ray detector is changed relatively to the subject, view by view,

wherein the image processing means comprises;

means for obtaining a set of three-dimensional volume data by obtaining a plurality of tomograms on the basis of a plurality of sets of the two-dimensional imaging signals detected at each view;

means for performing a filtering process to remove blur components from the three-dimensional volume data; and

means for obtaining the X-ray tomogram of the subject by performing image processing on the filtered data.

20. An X-ray diagnostic system of claim 14, wherein the means for performing a filtering process comprises a three-dimensionally isotropic filter configured to remove the blur components.

21. An X-ray diagnostic system of claim 14, wherein the means for performing a filtering process comprises a three-dimensionally anisotropic filter configured to remove the blur components.

22. An X-ray diagnostic system of claim 20, wherein the filtering process is performed along each of a plurality of paths of the X-ray.

23. An X-ray diagnostic system of claim 20, wherein the filtering process is performed along a representative of a plurality of paths of the X-ray.

7. An X-ray diagnostic system comprising:

an X-ray generator configured to irradiate an X-ray through a subject to be imaged;

a planar X-ray detector configured to detect the X-ray which has passed through the subject;

a C-shaped arm of which a one end supports the X-ray generator and of which an other end angle-adjustably supports the X-ray detector;

an arm holder configured to slidably and rotatably support the C-shaped arm; and

a holder supporting mechanism configured to rotatably support the arm holder.

12. An X-ray diagnostic system comprising:

an X-ray generator configured to irradiate an X-ray through a subject to be imaged;

a two-dimensional X-ray detector having a curved detecting plane onto which the X-ray impinges, configured to detect the X-ray which has passed through the subject with the curved detecting plane and to output two-dimensional imaging signals corresponding to the detected X-ray;

supporting/moving means for movably supporting the X-ray generator and the X-ray detector; and

image processing means for converting the two-dimensional imaging signals detected through the curved detecting plane into two-dimensional signals of a planar plane that constitutes a tomogram of the subject.

13. An X-ray diagnostic system comprising:

a two-dimensional X-ray detector configured to detect an X-ray passing through a subject to be imaged and configured to output two-dimensional imaging signals corresponding to the detected X-ray; and

supporting means for detachably supporting the two-dimensional detector,

wherein the two-dimensional X-ray detector comprises a plurality of X-ray detectors whose characteristics are different from each other, and the supporting means is constructed to exchangeably support the plurality of X-ray detectors.

15. An X-ray diagnostic system of claim 13, further comprising:

means for measuring an electrocardiograph signal of the subject; and

means for obtaining a tomogram of the subject on the basis of a plurality of sets of the two-dimensional imaging signals detected view by view when the electrocardiograph signal coincides with given timing points.

16. An X-ray diagnostic system comprising:

a couch configured to movably support a tabletop on which a subject to be imaged is laid;

an X-ray generator that has an X-ray focus and is configured to irradiate an X-ray through the subject;

a planar X-ray detector configured to detect the X-ray which has passed through the subject and configured to output two-dimensional imaging signals based on the detected X-ray;

supporting means for supporting the X-ray generator and the X-ray detector;

driving means for moving, view by view, at least one of spatial positions of the X-ray focus and the tabletop, thereby changing a relative spatial positional relationship between the X-ray focus and the subject;

calculating means for calculating the relative spatial positional relationship between the X-ray focus and the X-ray detector for each view;

processing means for obtaining a tomogram of the subject using the two-dimensional imaging signals detected view by view and the relative spatial positional relationship for each view,

wherein the supporting means comprises;

a C-shaped arm of which a one end supports the X-ray generator and of which an other end angle-adjustably supports the X-ray detector,

an arm holder configured to slidably and rotatably support the C-shaped arm, and

a holder supporting mechanism configured to rotatably support the arm holder.

17. An X-ray diagnostic system of claim 16, wherein the processing means includes:

means for setting a plane that includes the subject, the tomogram being formed along the plane and an inclination of the plane to the subject being changeable;

means for determining coordinates contained in the plane; and

means for obtaining, as the tomogram, image information about the coordinates using the two-dimensional imaging signals detected view by view and the relative spatial positional relationship calculated for each view.

18. An X-ray diagnostic system of claim 16, wherein the processing means includes:

means for setting a curved plane that includes the subject, the tomogram being formed along the curved plane;

means for determining coordinates contained in the curved plane; and

means for obtaining, as the tomogram, image information about the coordinates using the two-dimensional imaging signals detected view by view and the relative spatial positional relationship calculated for each view.

19. An X-ray diagnostic system of claim 16, wherein the supporting means comprises:

a first means for supporting the X-ray generator; and

a second means for supporting the X-ray detector, the first and second supporting means being separable and the second supporting means being portable.