Method and system for diagnosing faults in imaging scanners

• US 6,275,559 B1
• Filed: 10/08/1999
• Issued: 08/14/2001
• Est. Priority Date: 10/08/1999
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Dusing, Randal Vincent, Edic, Peter Michael, Alyassin, Abdalmajeid Musa, Shah, Rasiklal Punjalal, Ramani, Vipin Kewal, Guru, Shankar Visvanathan
• Primary Examiner(s): BRUCE, DAVID VERNON
• Application Number:
  US09/415,409
• Time in Patent Office: 676 Days
• Field of Search: 378/4, 378/207, 378/901
• US Class Current: 378/4
• CPC Class Codes: A61B 6/583 using calibration phantoms
• CPC Class Codes: G06T 1/0007 Image acquisition

Abstract

A system is provided for identifying faults in a non-OEM computed tomography system having components in connection with the detectors to reconstruct an image. Then, correlation values are derived from baseline reference data files and current data files collected after a fault is suspected in the CT system. The correlation values are compared against a threshold to identify suspect detectors and a pattern recognition algorithm is applied to determine if the suspect detectors are faulty or if one of the components processing the output signals has failed. If baseline files are unavailable, the identification of faulty components is accomplished by performing correlation between the current data files and average profile values.

Claims

1. A diagnostic system for identifying faults in an imaging system having a plurality of detectors generating output signals and a plurality of components in connection with the detectors for reconstructing images from the output signals generated by the plurality of detectors, said diagnostic system comprising:

a memory storing at least one current data file which includes data output by one of the plurality of components after a fault is suspected in the imaging system; and

a processor in connection with the memory for processing said at least one current data file to identify faulty detector and component.

2. The diagnostic system of claim 1, wherein said diagnostic system is used to identify faults in a non-OEM imaging system by only utilizing non-proprietary information contained in said at least one current data file.

3. The diagnostic system of claim 1, wherein said at least one current data file includes at least one of the following:

detector output signal data, source fan data, detector fan data, filtered data, convolved data, and image data.

4. The diagnostic system of claim 1, wherein the imaging system is a computed tomography system having a radiation source projecting a fan beam of radiation and the output signals generated by the detectors are proportional to the intensity of radiation impinging at each respective detector.

5. The diagnostic system of claim 4, wherein the at least one current data file includes a plurality of profiles collected at a plurality of scan angles, each respective of said plurality of profiles including measurement values representative of intensity signals from the detectors, wherein said plurality of profiles are used to reconstruct a cross-sectional image.

6. The diagnostic system of claim 4, wherein the at least one current data file includes a plurality of current measurement values P_ik, each of the measurement values P_ik corresponding to the signals generated by the i^th detector at k^th profile.

7. The diagnostic system of claim 6, wherein the processor is configured to calculate average profile values P_k which are calculated as follows:

$P_k=\frac{\underset{i=1}{\overset{m}{\sum <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>P_{\mathrm{ik}}}{i}.$

8. The diagnostic system of claim 7, wherein the processor is configured to obtain correlation values by correlating the measurement values P_ik with the average profile values P_k, wherein the correlation values are calculated as follows:

9. The diagnostic system of claim 8, wherein the correlation values are compared against a threshold to identify detectors which are suspected of faulty operations.

10. The diagnostic system of claim 9, wherein the processor is configured to determine whether a predetermined pattern of suspect detectors has occurred based on the correlation values, and further wherein the processor is configured to identify a faulty component which corresponds to such predetermined pattern.

11. The diagnostic system of claim 6, wherein the memory stores at least one baseline reference data file which includes data output by one of the plurality of components while the imaging system is operating properly.

12. The diagnostic system of claim 11, wherein the at least one baseline reference data file includes a plurality of baseline reference measurement values B_ik, each of the baseline reference measurement values B_ik corresponding to the signals generated by the i^th detector at k^th profile.

13. The diagnostic system of claim 12, wherein the processor is configured to obtain correlation values by correlating the current measurement values P_ik with the baseline reference measurement values B_ik, wherein the correlation values are calculated as follows:

14. The diagnostic system of claim 13, wherein the correlation values are compared against a threshold to identify detectors which are suspected of faulty operations.

15. The diagnostic system of claim 14, wherein the processor is configured to determine whether a predetermined pattern of suspect detectors has occurred based on the correlation values, and further wherein the processor is configured to identify a faulty component which corresponds to such predetermined pattern.

16. The diagnostic system of claim 1, further comprising a user interface in connection with the processor for displaying possible faulty components in the computed tomography system and recommend repair procedure actions based on identified failures.

17. A diagnostic system for identifying faults in a non-OEM imaging system without utilizing proprietary information, said non-OEM imaging system having a plurality of detectors generating output signals and a plurality of components in connection with the detectors for reconstructing images from the output signals generated by the plurality of detectors, said diagnostic system comprising:

means for collecting at least one current data file including data output by one of the plurality of components after a fault is suspected in the imaging system, said at least one current data file including processed output signals generated by said plurality of detectors at a plurality of scan angles;

means for obtaining at least one baseline reference data file including data that would be output by said one of the plurality of components if the imaging system is operating faultlessly;

means for comparing said at least one current data file with said at least one baseline reference data file using a correlation operation to produce correlation values; and

means for identifying faulty detector and component based on the correlation values.

18. The diagnostic system of claim 17, wherein said at least one current data file includes at least one of the following:

detector output signal data, source fan data, detector fan data, filtered data, convolved data, and image data.

19. The diagnostic system of claim 17, wherein said at least one baseline reference data file is obtained while the imaging system is operating properly by collecting data output by said one of the plurality of components.

20. The diagnostic system of claim 17, wherein:

said at least one current data file comprises a plurality of current measurement values P_ik, each of the measurement values P_ik corresponding to processed signals originally output by the i^th detector at k^th profile;

said at least one baseline reference data file is obtained by calculating average profile values P_k which are calculated as follows;

$P_k=\frac{\underset{i=1}{\overset{m}{\sum <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>P_{\mathrm{ik}}}{i}$

said correlation values are obtained by correlating the measurement values P_ik with the average profile values P_k, wherein the correlation values are calculated as follows;

21. A diagnostic method for identifying faults in an imaging system having a plurality of detectors generating output signals and a plurality of components coupled to the detectors for reconstructing images from the output signals generated by the detectors, said diagnostic method comprising the steps of:

collecting at least one current data file output by one of the plurality of components after a fault is suspected in the imaging system; and

processing said at least one current data file to identify possible faulty detectors and components.

22. The diagnostic method of claim 21, wherein said diagnostic method is used to identify faults in a non-OEM imaging system by only utilizing non-proprietary information extracted from said at least one current data file collected.

23. The diagnostic method of claim 21, wherein the imaging system is a computed tomography system having a radiation source projecting a fan beam of radiation and the output signals generated by the detectors are proportional to the intensity of radiation impinging at each respective detector.

24. The diagnostic method of claim 23, wherein the at least one current data file includes a plurality of profiles collected at a plurality of scan angles, each respective of said plurality of profiles including output signals received from the detectors at a corresponding scan angle, wherein said plurality of profiles is used to reconstruct a cross-sectional image.

25. The diagnostic method of claim 23, wherein the at least one current data file includes a plurality of current measurement values P_ik, each of the measurement values P_ik corresponding to the signals generated by the i^th detector at k^th profile.

26. The diagnostic method of claim 25, further comprising the steps of:

calculating average profile values P_k which are calculated as follows;

$P_k=\frac{\underset{i=1}{\overset{m}{\sum <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>P_{\mathrm{ik}}}{i}$

calculating correlation values by correlating the measurement values P_ik with the average profile values P_k, wherein the correlation values are calculated as follows;

27. The diagnostic method of claim 26, further comprising the steps of:

determining whether one of a plurality of predetermined pattern of suspect detectors has occurred; and

identifying a faulty component which corresponds to the predetermined pattern.

28. The diagnostic method of claim 21, further comprising the step of collecting at least one baseline reference data file output from one of the plurality of components while the imaging system is operating properly.

29. The diagnostic method of claim 28, wherein the at least one baseline reference data file includes a plurality of baseline reference measurement values B_ik, each of the baseline reference measurement values B_ik corresponding to the signals generated by the i^th detector at k^th profile.

30. The diagnostic method of claim 29, further comprising the steps of:

calculating correlation values by correlating the current measurement values P_ik with the baseline reference measurement values B_ik, wherein the correlation values are calculated as follows;

31. The diagnostic method of claim 30, further comprising the steps of:

determining whether one of a plurality of predetermined pattern of suspect detectors has occurred; and

identifying a faulty component which corresponds to such predetermined pattern.