Methods for automatic protocol selection

• US 7,542,792 B2
• Filed: 06/01/2004
• Issued: 06/02/2009
• Est. Priority Date: 06/01/2004
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Miesbauer, Diane Marie, Stearns, Charles William, Wollenweber, Scott David
• Primary Examiner(s): Le; Long V
• Assistant Examiner(s): Gupta; Vani
• Application Number:
  US10/858,137
• Publication Number:
  US 20050267348A1
• Time in Patent Office: 1,827 Days
• Field of Search: 600/407, 600/425, 600/428, 250/370.08, 250/370.09
• US Class Current: 600/407
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/542 involving control of exposure
• CPC Class Codes: A61B 6/544 dependent on patient size
• CPC Class Codes: A61B 6/545 involving automatic set-up of acquisition parameters

Abstract

A method and apparatus for imaging a patient is provided. The method includes receiving patient information, automatically selecting an imaging protocol based on the received information, and performing an imaging scan of the patient using the automatically selected imaging protocol.

Claims

1. A method of imaging a patient, said method comprising:

receiving patient information;

measuring prompt and random coincidence rates in real time using a scout scan performed by a medical imaging system;

automatically selecting an imaging protocol based on the received information and the measured prompt and random coincidence rates; and

performing, with the medical imaging system, an imaging scan of the patient using the automatically selected imaging protocol.

2. A method in accordance with claim 1 wherein receiving patient information comprises prompting a user to enter the patient information using a user interface.

3. A method in accordance with claim 1 wherein receiving patient information comprises receiving at least one of a height and a weight of the patient.

4. A method in accordance with claim 1 wherein receiving patient information comprises receiving the patient information from a database accessible to the imaging system through a data network.

5. A method in accordance with claim 4 wherein receiving patient information comprises receiving the patient information from a DICOM system.

6. A method in accordance with claim 1 wherein performing an imaging scan of the patient using the automatically selected imaging protocol comprises determining at least one of an emission frame and a transmission frame.

7. A method in accordance with claim 1 wherein performing an imaging scan of the patient using the automatically selected imaging protocol comprises determining an axial field of view (N) using,

N=Ceil (1+(H−

(S*T))/(S−

1)*T), where

N is an integer value representing the number of axial fields-of-view to be imaged;

Ceil is a ceiling function;

H=a patient height in cm,

S=a number of slices per AFOV, and

T=a slice thickness.

8. A method in accordance with claim 1 wherein measuring prompt and random coincidence rates in real time using a scout scan comprises performing a scan of relatively short time duration using full acceptance angles.

9. A method in accordance with claim 1 wherein measuring prompt and random coincidence rates in real time using a scout scan comprises performing a scan of less than ten seconds using full acceptance angles.

10. A method in accordance with claim 9 further comprising generating a noise-equivalent-count-rate (NECR) versus acceptance angle curve using the measured prompt and random coincidence rates.

11. A method in accordance with claim 10 further comprising determining an optimal acceptance angle for performing the imaging scan using the NECR versus acceptance angle curve.

12. A method in accordance with claim 1 wherein performing an imaging scan of the patient using the automatically selected imaging protocol comprises modifying, in real time, at least one of an axial acceptance angle, a coincidence timing window, an energy window, a use and configuration of slice septa of the scan using the measured prompt and random coincidence rates.

13. A method in accordance with claim 1 wherein performing an imaging scan of the patient using the automatically selected imaging protocol comprises estimating a scatter coincidence rate using the prompt and the random coincidence rates.

14. A method in accordance with claim 13 wherein performing an imaging scan of the patient using the automatically selected imaging protocol comprises modifying, in real time, at least one of an axial acceptance angle, a coincidence timing window, an energy window, the use and configuration of slice septa of the scan using the estimated scatter coincidence rate and the personal information.

15. A method of imaging a patient using a medical imaging scanner, said method comprising:

receiving information relative to a patient'"'"'s size and density;

automatically selecting an imaging protocol to operate a medical imaging system, the imaging protocol based on the received information wherein the protocol includes at least one of an axial acceptance angle, a coincidence timing window, an energy window, a “

d-ness”

of the scan;

acquiring a prompt coincidence rate and a random coincidence rate at an imaging frame;

modifying a imaging protocol using the received information, the prompt coincidence rate, and the random coincidence rate; and

performing with the medical imaging system an imaging scan of the patient using the modified imaging protocol.

16. A method in accordance with claim 15 wherein modifying a imaging protocol using the received information comprises modifying the axial acceptance angle to an optimal acceptance angle, using the patient size and the acquired prompt coincidence rate and the random coincidence rate.

18. A method in accordance with claim 15 further comprising generating a function curve relating an NECR for the scanner at a plurality of scanner acceptance angles.

19. A method in accordance with claim 18 further comprising selecting an acceptance angle corresponding to a peak NECR of the function curve to perform the imaging scan.

20. A method in accordance with claim 18 further comprising selecting an acceptance angle corresponding to a NECR value peak of the function curve to perform the imaging scan.

17. A method in accordance with 15 wherein acquiring a prompt coincidence rate and a random coincidence rate at an imaging frame comprises acquiring a prompt coincidence rate and a random coincidence rate using a full acceptance angle setting.

21. An imaging system for imaging a patient, said system comprising:

a first imaging modality unit having a patient bore therethrough;

a second imaging modality unit having a patient bore therethrough;

a control mechanism configured to measure prompt and random coincidence rates in real time using a scout scan, and communicatively coupled to said first imaging modality unit and said second imaging modality unit to control movement of said first imaging modality unit and said second imaging modality unit;

an automatic protocol selector configured to receive data relating to a patient, parameters relating to a type of scan to be performed, and a selection of a predetermined protocol stored in a database of said control mechanism, said automatic protocol selector further configured to determine a scan protocol using at least one of the data relating to the patient, the parameters relating to the type of scan to be performed, and the selected predetermined protocol and the measured prompt and random coincidence rates.

22. An imaging system in accordance with claim 21 further configured to:

rotate at least one of said first imaging modality unit and said second imaging modality unit to a image frame position;

acquire prompt and random coincidence event rates during a scout scan;

determine an axial acceptance angle that facilitates a maximizing a noise-equivalent-count-rate that is based on the acquired prompt and random coincidence event rates; and

perform an image data acquisition at said image frame position.

23. An imaging system in accordance with claim 21 wherein said first imaging modality unit is a PET imaging system and said second imaging modality unit is a CT imaging system.

24. A computer program embodied on a computer readable medium for automatically selecting an imaging protocol using an automatic protocol selector coupled to said imaging system, said imaging system including a database and a user interface, said program comprising a code segment that prompts a user to select a predetermined protocol stored in said database and then:

displays a function menu on said user interface to prompt the user to input data relating to a type of scan to be performed;

prompts the user to input patient data relating to a patient to be scanned;

measures prompt and random coincidence rates in real time using a scout scan; and

determines a protocol for the scan based on the predetermined protocol, the type of scan to be performed, the patient data, and the prompt and random coincidence rates.

25. A computer program in accordance with claim 24 further comprising a code segment configured to prompt a user to accept the determined protocol.

26. A computer program in accordance with claim 24 further comprising a code segment configured to transmit at least one parameter of the determined protocol to a data acquisition system.

27. A computer program in accordance with claim 24 further comprising a code segment configured to transmit at least one parameter of the determined protocol to an image reconstructor.

28. A computer program in accordance with claim 24 further comprising a code segment configured to transmit control signals to at least one of an x-ray controller, that provides power and timing signals to an x-ray source, a gantry motor controller, and a table motor controller.

29. A computer program in accordance with claim 24 wherein said first imaging modality unit is a PET imaging system and said second imaging modality unit is a CT imaging system.