Method and apparatus for processing a fluoroscopic image

• US 20030072418A1
• Filed: 10/15/2001
• Published: 04/17/2003
• Est. Priority Date: 10/15/2001
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Tkaczyk, John Eric, Albagli, Douglas, Yanoff, Brian David, Xue, Ping, Possin, George Edward
• Granted Patent: US 6,621,887 B2
• Time in Patent Office: Days
• US Class Current: 378/207
• CPC Class Codes: A61B 6/583 using calibration phantoms
• CPC Class Codes: A61B 6/585 Calibration of detector units
• CPC Class Codes: H04N 25/63 applied to dark current
• CPC Class Codes: H04N 5/325 Image enhancement, e.g. by subtraction techniques using polyenergetic X-rays

Abstract

In one aspect of the invention a method for processing a fluoroscopic image is provided. The method includes scanning an object with an imaging system including at least one radiation source and at least one detector array, acquiring a plurality of dark images to generate a baseline image, acquiring a plurality of lag images subsequent to the baseline image, determining a plurality of parameters of a power law using at least one lag image and at least one baseline image, and performing a log-log extrapolation of the power law including the determined parameters.

Claims

1. A method for processing a fluoroscopic image, said method comprising:

scanning an object with an imaging system including at least one radiation source and at least one detector array;

acquiring a plurality of dark images to generate a baseline image;

acquiring a plurality of lag images subsequent to the baseline image;

determining a plurality of parameters of a power law using at least one lag image and at least one baseline image;

performing a log-log extrapolation of the power law including the determined parameters.

2. A method in accordance with claim 1 wherein acquiring a plurality of dark images to generate a baseline comprises averaging the plurality of dark images to generate at least one baseline image.

3. A method in accordance with claim 1 further comprises subtracting the log-log extrapolation value from at least one fluoroscopic image to generate a lag-corrected fluoroscopic image.

4. A method in accordance with claim 3 wherein the log-log extrapolation is spatially filtered prior to subtraction.

5. A method for processing a fluoroscopic image comprising:

scanning an object with an imaging system including at least one radiation source and at least one detector array;

acquiring a plurality of dark images;

averaging the plurality of dark images to generate at least one baseline image;

acquiring a plurality of lag images subsequent to the baseline image;

determining a plurality of parameters of a power law using at least one lag image and at least one baseline image;

performing a log-log extrapolation of the power law including the determined parameters;

spatially filtering the log-log extrapolation; and

subtracting the log-log extrapolation value from at least one fluoroscopic image to generate a lag-corrected fluoroscopic image.

6. A medical imaging system for processing a fluoroscopic image, said medical system comprising:

a detector array;

at least one radiation source; and

a computer coupled to said detector array and said radiation source, said computer configured to;

scan an object;

acquire a plurality of dark images to generate a baseline image;

acquire a plurality of lag images subsequent to the baseline image;

determine a plurality of parameters of a power law using at least one lag image and at least one baseline image;

perform a log-log extrapolation of the power law including the determined parameters.

7. A medical imaging system in accordance with claim 6, wherein to acquire a plurality of dark images to generate a baseline, said computer is further configured to average the plurality of dark images to generate at least one baseline image.

8. A medical imaging system in accordance with claim 6 wherein to process a fluoroscopic image, said computer is further configured to subtract the log-log extrapolation value from at least one fluoroscopic image to generate a lag-corrected fluoroscopic image.

9. A medical imaging system in accordance with claim 8 wherein said computer is further configured to spatially filter the log-log extrapolation prior to subtraction.

10. A medical imaging system for processing a fluoroscopic image, said medical system comprising:

a detector array;

at least one radiation source; and

a computer coupled to said detector array and said radiation source, said computer configured to;

acquire a plurality of dark images;

average the plurality of dark images to generate at least one baseline image;

acquire a plurality of lag images subsequent to the baseline image;

determine a plurality of parameters of a power law using at least one lag image and at least one baseline image;

perform a log-log extrapolation of the power law including the determined parameters;

filter the log-log extrapolation spatially; and

subtract the log-log extrapolation value from at least one fluoroscopic image to generate a lag-corrected fluoroscopic image.

11. A computer readable medium encoded with a program executable by a computer for processing a fluoroscopic image, said program configured to instruct the computer to:

scan an object with an imaging system including at least one radiation source and at least one detector array;

acquire a plurality of dark images to generate a baseline image;

acquire a plurality of lag images subsequent to the baseline image;

determine a plurality of parameters of a power law using at least one lag image and the baseline image;

perform a log-log extrapolation of the power law including the determined parameters.

12. A computer readable medium in accordance with claim 11 wherein to process a fluoroscopic image, said program configured to average the plurality of dark images to generate at least one baseline image.

13. A computer readable medium in accordance with claim 11 wherein to process a fluoroscopic image, said program configured to subtract the log-log extrapolation value from at least one fluoroscopic image to generate a lag-corrected fluoroscopic image.

14. A computer readable medium in accordance with claim 13, said program configured to spatially filter the log-log extrapolation prior to subtraction.

15. A computer readable medium encoded with a program executable by a computer for processing a fluoroscopic image, said program configured to instruct the computer to:

scan an object with an imaging system including at least one radiation source and at least one detector array;

acquire a plurality of dark images;

average the plurality of dark images to generate at least one baseline image;

acquire a plurality of lag images subsequent to the baseline image;

determine a plurality of parameters of a power law using at least one lag image and at least one baseline image;

perform a log-log extrapolation of the power law including the determined parameters;

filter the log-log extrapolation spatially; and

subtract the log-log extrapolation value from at least one fluoroscopic image to generate a lag-corrected fluoroscopic image.

16. A method for processing a fluoroscopic image comprising:

scanning an object with an imaging system including at least one radiation source and at least one detector array;

acquiring a plurality of dark images to generate a baseline image;

acquiring at least one first radiation image subsequent to the baseline image;

acquiring a second dark image subsequent to the first radiation image;

acquiring a second radiation image subsequent to the second dark image;

generating a lag prediction image by subtracting the baseline image from the second dark image; and

subtracting the lag prediction image from at least one subsequent radiation image to generate at least one lag-corrected fluoroscopic image.

17. A method in accordance with claim 16 wherein generating at least one lag prediction image comprises generating at least one lag prediction image using a constant offset value.

18. A method in accordance with claim 16 wherein generating at least one lag prediction image comprises generating at least one lag prediction image using a polynomial.

19. A method in accordance with claim 16 wherein subtracting the lag prediction image from at least one radiation image to generate at least one lag-corrected image comprises filtering the lag prediction image prior to subtraction.

20. A method for processing a fluoroscopic image comprising:

scanning an object with an imaging system including at least one radiation source and at least one detector array;

scanning an object with an imaging system including at least one radiation source and at least one detector array;

generating a baseline image;

acquiring at least one radiation image subsequent to the dark image; and

acquiring a dark image every n^th frame; and

acquiring a dark image every m^th frame, where m>

n.

21. A method in accordance with claim 20 wherein acquiring a dark image every n^th frame includes filtering the lag prediction image.