METHOD AND APPARATUS FOR FOCAL SPOT POSITION TRACKING

• US 20160199019A1
• Filed: 01/13/2015
• Published: 07/14/2016
• Est. Priority Date: 01/13/2015
• Status: Abandoned Application

• Current Assignee: Arineta Ltd.
• Original Assignee: Arineta Ltd.
• Inventors: VOLOKH, Lana, KUKSIN, Evgeniy, RUIMI, David
• Application Number:
  US14/595,564
• Publication Number:
  US 20160199019A1
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 6/4291 the detector being combined with a grid or grating
• CPC Class Codes: A61B 6/5258 involving detection or reduction of artifacts or noise
• CPC Class Codes: A61B 6/547 involving tracking of position of the device or parts of the device

Abstract

A tracking system for tracking focal spot position of an x-ray source includes a detector array including a plurality of detecting elements sensitive to x-ray radiation and a grid overlaid on a detecting surface of the detector array. The grid is formed from an array of vanes and has a density greater than a density of the detector array.

Claims

1. A tracking system for tracking focal spot position of an x-ray source, the tracking system comprising:

a detector array including a plurality of detecting elements sensitive to x-ray radiation; and

a grid overlaid on a detecting surface of the detector array, wherein the grid is formed from an array of vanes and wherein a density of the grid is greater than a density of the detector array.

2. The tracking system according to claim 1, wherein both the detector array is a one dimensional array and the array of vanes is a one dimensional array that is distributed across the array of detecting elements.

3. The tracking system according to claim 1, wherein the vanes in the array are parallel to each other.

4. The tracking system according to claim 1, wherein the vanes of the grid are orthogonal to the detecting surface of the detector array.

5. The tracking system according to claim 1, comprising a filter positioned over the detecting surface of the detector array and between the detector array and grid.

6. The tracking system according to claim 1, comprising a filter positioned over a surface of the grid that is distal to the detecting surface of the detector array.

7. The tracking system according to claim 1, wherein a ratio between a height of the vanes and a distance between contiguous vanes is defined to range between 8-15.

8. The tracking system according to claim 1, wherein the detector elements provide a 0.5-2 mm pixel resolution.

9. The tracking system according to claim 1, comprising a processing unit for tracking focal spot position or focal spot movement based on output sampled from the detector array.

10. An x-ray device comprising:

an x-ray source emitting x-ray radiation from a focal spot;

a collimator collimating radiation emitted from the x-ray source; and

a tracking system according to claim 1 receiving a portion of the radiation of the x-ray source does not penetrate through the collimator.

11. The x-ray device according to claim 10, wherein the tracking system is positioned 5-15 cm from the focal spot.

12. The x-ray device according to claim 10, wherein the tracking system receives the first portion of radiation directly from the focal spot without magnification of the focal spot.

13. The x-ray device according to claim 10, wherein the x-ray source emits x-ray radiation from two focal spots and wherein the tracking system receives the first portion of radiation from one of the two focal spots.

14. The x-ray device according to claim 10, wherein the x-ray device is retrofitted with the tracking system.

15. The x-ray device according to claim 10, wherein the collimator is adjustable and is adapted to follow the focal spot position as detected by the tracking system.

16. The x-ray device according to claim 10, comprising:

a second focal spot from which x-ray radiation is emitted; and

a second collimator collimating radiation from the second focal spot.

17. The x-ray device according to claim 16, comprising a second tracking system receiving a portion of the radiation that does not penetrate through the second collimator, wherein the second tracking system comprises:

a detector array including a plurality of detecting elements sensitive to x-ray radiation; and

a grid overlaid on a detecting surface of the detector array, wherein the grid is formed from an array of vanes and wherein a density of the grid is greater than a density of the detector array.

18. The x-ray system according to claim 16, wherein the second focal spot is provided with a second x-ray source.

19. A CT scanner comprising:

a gantry, wherein the gantry houses;

a rotating frame that rotates about a Z axis;

an x-ray device comprising;

an x-ray source emitting x-ray radiation from a focal spot;

a collimator collimating radiation emitted from the x-ray source;

and

a tracking system according to claim 1 receiving a portion of the radiation of the x-ray source does not penetrate through the collimator,

wherein the x-ray device is mounted on the rotating frame; and

a scanning detector array, wherein the scanning detector array is mounted on the rotating frame and opposite the x-ray device; and

a controller that controls operation of the CT scanner.

20. The scanner according to claim 19, wherein the array of vanes of the grid is aligned to parallel with the Z axis.

21. The scanner according to claim 19, comprising a second x-ray device, the second x-ray device comprising:

a second x-ray source emitting x-ray radiation from a focal spot;

a collimator collimating radiation emitted from the second x-ray source; and

a second tracking system comprising;

a second detector array including a plurality of detecting elements sensitive to x-ray radiation; and

a grid overlaid on a detecting surface of the second detector array,

wherein the grid is formed from an array of vanes and wherein a density of the grid is greater than a density of the detector array,

wherein the second tracking system receives a portion of the radiation of the x-ray source does not penetrate through the collimator and wherein the second x-ray device is mounted on the rotating frame.

22. The scanner according to claim 19, wherein the controller is operative to receive input from the tracking system of the x-ray device and to adjust reconstruction of images generated from output obtained from the scanning detector array based on the input received.

23. A method for tracking position of a focal spot of an x-ray source, the method comprising:

detecting radiation emitted from a focal spot with an array of x-ray sensitive detectors, wherein the radiation detected is radiation that passed through an array of vanes and wherein a density of the array of vanes is greater than a density of the array of x-ray sensitive detectors;

modeling output from the detector array;

identifying a peak in the model of the output; and

associating position of the focal spot with the peak of the model.

24. The method according to claim 23, comprising:

positioning the array of x-ray sensitive detectors at distance of between 5-15 cm from the focal spot.

25. The method according to claim 23, comprising detecting radiation with the array of x-ray sensitive detectors absent magnification of the focal spot.

26. The method according to claim 23, comprising adjusting a collimator associated with the x-ray source responsive to a current position of the focal spot.

27. The method according to claim 23, comprising adjusting image reconstruction of images captured responsive to a current position of the focal spot.