Image acquisition and processing chain for dual-energy radiography using a portable flat panel detector

• US 7,627,084 B2
• Filed: 03/30/2007
• Issued: 12/01/2009
• Est. Priority Date: 03/30/2007
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Jabri, Kadri Nizar, Sabol, John Michael, Avinash, Gopal Biligeri, Uppaluri, Renuka
• Primary Examiner(s): SONG, HOON K
• Application Number:
  US11/731,535
• Publication Number:
  US 20080240357A1
• Time in Patent Office: 977 Days
• Field of Search: 378/98.8, 378/62, 378/205, 378/207, 378/154, 378/155
• US Class Current: 378/62
• CPC Class Codes: A61B 6/4035 the source being combined with a filter or grating
• CPC Class Codes: A61B 6/4291 the detector being combined with a grid or grating
• CPC Class Codes: A61B 6/4405 the apparatus being movable or portable, e.g. handheld or mounted on a trolley
• CPC Class Codes: A61B 6/482 involving multiple energy imaging
• CPC Class Codes: A61B 6/5252 removing objects from field of view, e.g. removing patient table from a CT image
• CPC Class Codes: A61B 6/541 involving acquisition triggered by a physiological signal
• CPC Class Codes: A61B 6/587 Alignment of source unit to detector unit

Abstract

A mobile dual-energy X-ray imaging system is presented. The mobile dual-energy X-ray imaging system is a digital X-ray system that is designed both to acquire original image data and to process the image data to produce an image for viewing. The system has an X-ray source and a portable flat-panel digital X-ray detector. The system is operable to produce a high energy image and low energy image, which may be decomposed to produce a soft tissue image and a bone image for further analysis of the desired anatomy. The system is disposed on a carrier to facilitate transport. The imaging system has an alignment system for facilitating alignment of the flat-panel digital detector with the X-ray source. The imaging system also comprises an anti-scatter grid and an anti-scatter grid registration system for removing artifacts of the anti-scatter grid from images.

Claims

1. A medical imaging system, comprising:

an X-ray source adapted to generate X-rays at a first energy level at a first point in time and a second energy level at a second point in time;

a power supply operable to supply power to the X-ray source to generate the X-rays at the first energy level and the second energy level;

a portable flat-panel digital X-ray detector operable to detect X-rays from the X-ray source at the first energy level and the second energy level, wherein the detector produces a first signal representative of X-ray intensity from X-rays produced at the first energy level and a second signal representative of X-ray intensity from X-rays produced at the second energy level;

a processor-based device operable to produce material specific images from at least the first and second signals received from the detector;

a carrier adapted to transport at least one of the X-ray source, the power supply, the digital X-ray detector and the processor-based device to a patient;

an anti-scatter grid disposed over the detector; and

an anti-scatter grid registration system to register the anti-scatter grid in a first material-specific image obtained from X-rays produced at the first energy level and a second material-specific image obtained from X-rays produced at the second energy level.

2. The medical imaging system as recited in claim 1, comprising:

a sensor operable to detect a patient'"'"'s respiratory cycle and to produce a signal representative of the patient'"'"'s respiratory cycle.

3. The medical imaging system as recited in claim 2, wherein the medical imaging system is adapted to acquire a first image at the first energy level and a second image at the second energy level at a desired phase of a patient'"'"'s respiratory cycle.

4. The medical imaging system as recited in claim 2, wherein the medical imaging system is adapted to acquire a first image at the first energy level at a given point during a first respiratory cycle and to acquire a second image at the second energy level at approximately the same given point on a subsequent respiratory cycle.

5. The medical imaging system as recited in claim 1, comprising an alignment sensor operable to produce an indication when the portable flat-panel digital X-ray detector and/or an anti-scatter grid are aligned with the X-ray source.

6. The medical imaging system as recited in claim 1, comprising a scatter-reducing pad, wherein the pad is adapted to provide a low-attenuation gap between the patient and the portable flat-panel digital X-ray detector.

7. The medical imaging system as recited in claim 1, comprising a temperature correction function to compensate detector gain for the portable flat-panel digital X-ray detector caused by a change in detector temperature.

8. The medical imaging system as recited in claim 1, wherein the processor-based device comprises an anti-scatter algorithm.

9. The medical imaging system as recited in claim 1, comprising an image decomposition process having a log subtraction algorithm comprising a spatially-variable parameter.

10. The medical imaging system as recited in claim 1, wherein the material specific images comprises a soft-tissue image and a bone image.

11. An imaging system, comprising:

an X-ray device adapted to generate X-rays at a first energy level at a first point in time and a second energy level at a second point in time;

a portable flat-panel digital X-ray detector operable to detect X-rays from the X-ray source at the first energy level and the second energy level, wherein the detector produces a first signal representative of X-ray intensity from X-rays produced at the first energy level and a second signal representative of X-ray intensity from X-rays produced at the second energy level;

an image processing system coupled to the detector and operable to produce a first image based on the first signal representative of X-ray intensity and a second image based on the second signal representative of X-ray intensity;

an anti-scatter grid disposed over the detector; and

a grid registration system operable to register the anti-scatter grid in the first image and in the second image.

12. The imaging system as recited in claim 11, comprising a processor-based device associated with the detector, wherein the processor-based device is operable to produce a soft tissue image and a bone image from the first image and the second image.

13. The imaging system as recited in claim 11, wherein the grid registration system comprises an algorithm operable to register an image containing the anti-scatter grid in the first image with an image containing the anti-scatter grid in the second image.

14. The imaging system as recited in claim 11, comprising an alignment system operable to detect detector and/or grid position relative to the X-ray source, wherein the alignment system is coupled to the grid registration system and the gird registration system is adapted to register the anti-scatter grid in the first image and the second image based on data from the alignment system.

15. A medical imaging system, comprising:

an X-ray source adapted to generate X-rays at a first energy level at a first point in time and a second energy level at a second point in time;

a power supply operable to supply power to the X-ray source to generate the X-rays at the first energy level and the second energy level;

a portable flat-panel digital X-ray detector operable to detect X-rays from the X-ray source at the first energy level and the second energy level, wherein the detector produces a first signal representative of X-ray intensity from X-rays produced at the first energy level and a second signal representative of X-ray intensity from X-rays produced at the second energy level;

an image processing system coupled to the detector and operable to produce a first image based on the first signal representative of X-ray intensity and a second image based on the second signal representative of X-ray intensity;

a carrier adapted to transport at least one of the X-ray source, the power supply, the digital X-ray detector and the processor-based device to a patient;

an anti-scatter grid disposed over the detector;

an anti-scatter grid registration system to register the anti-scatter grid in a first material-specific image obtained from X-rays produced at the first energy level and a second material-specific image obtained from X-rays produced at the second energy level; and

an alignment sensor operable to produce an indication when the portable flat-panel digital X-ray detector is aligned with the X-ray source.

16. The medical imaging system of claim 15, comprising a sensor operable to detect a patient'"'"'s respiratory cycle and to produce a signal representative of the patient'"'"'s respiratory cycle.

17. The medical imaging system as recited in claim 16, wherein the medical imaging system is adapted to acquire a first image at the first energy level and a second image at the second energy level at a desired phase of a patient'"'"'s respiratory cycle.

18. The medical imaging system as recited in claim 16, wherein the medical imaging system is adapted to acquire a first image at the first energy level at a given point during a first respiratory cycle and to acquire a second image at the second energy level at approximately the same given point on a subsequent respiratory cycle.

19. The imaging system as recited in claim 15, comprising a processor-based device associated with the detector, wherein the processor-based device is operable to produce a soft tissue image and a bone image from the first image and the second image.

20. The medical imaging system as recited in claim 19, wherein the processor-based device is linked to a data network to enable soft tissue and bone image viewing from remote locations.