System and method for interactive image contrast control in a magnetic resonance imaging system

• US 6,377,046 B1
• Filed: 06/08/2000
• Issued: 04/23/2002
• Est. Priority Date: 11/25/1998
• Status: Expired due to Fees

• Current Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Original Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Inventors: Prorok, Richard J., Debbins, Josef P., Ploetz, Lawrence E., Francis, Roshy J.
• Primary Examiner(s): ARANA, LOUIS M
• Application Number:
  US09/590,334
• Time in Patent Office: 684 Days
• Field of Search: 324/309, 324/314, 324/300, 324/306, 324/312, 324/307, 324/322
• US Class Current: 324/309
• CPC Class Codes: G01R 33/28 Details of apparatus provided for in groups G01R33/44 - G01R33/64
• CPC Class Codes: G01R 33/54 Signal processing systems, e.g. using pulse sequences ; Generation or control of pulse sequences; Operator console

Abstract

A magnetic resonance (MR) imaging system equipped with real-time imaging capability and method of interactively prescribing image contrast are disclosed herein. The MR imaging system includes a sequence controller for constructing MR imaging pulse sequences and a waveform memory for storing waveform segments. The MR imaging system allows an operator to interactively prescribe image contrast mechanism prior to and/or during real-time imaging. The use of image contrast waveform segments, only as needed, minimizes unnecessary MR scan time.

Claims

1. A method for interactively prescribing an image contrast of a magnetic resonance (MR) image produced in a magnetic resonance (MR) imaging system, comprising:

(a) storing a plurality of waveform segments in a waveform memory, wherein each of the waveform segments is associated with a distinct memory address and at least one of the waveform segment includes an image contrast mechanism;

(b) selecting from the plurality of waveform segments stored in the waveform memory;

(c) constructing an MR pulse sequence in real-time by dynamically connecting selected waveform segments at run-time; and

(d) acquiring MR data in real-time by execution of the MR pulse sequence to generate a current MR image that includes a desired image contrast.

2. The method of claim 1, wherein each of the waveform segments is comprised of at least one of a radio frequency (RF) waveform segment and a gradient waveform segment.

3. The method of claim 1, wherein the storing step includes storing at least one imaging waveform segment and at least one image contrast waveform segment.

4. The method of claim 3, further comprising (e) reconstructing the MR data to generate the current MR image in real-time and (f) displaying the current MR image.

5. The method of claim 4, further comprising repeating steps (d)-(e) a plurality of times with appropriate modifications to the MR pulse sequence at each repetition to acquire enough MR data in accordance with a resolution of the current MR image.

6. The method of claim 4, further comprising (g) subsequently selecting from the plurality of waveform segments stored in the waveform memory while any of steps (c)-(g) is in progress to prescribe a new image contrast.

7. The method of claim 6, further comprising halting any of steps (c)-(f) in progress when the subsequently selecting step (g) occurs.

8. The method of claim 7, further comprising constructing a new MR pulse sequence in real-time by dynamically connecting the subsequently selected waveform segments, as specified in the subsequently selecting step (g), and executing the new MR pulse sequence in real-time to generate a new MR image that includes the new image contrast.

9. The method of claim 8, wherein constructing a new MR pulse sequence includes instantaneously accessing the subsequently selected waveform segments in place of the selected waveform segments when the constructing step (c) in progress and then the subsequently selecting step (g) occurs.

10. The method of claim 6, wherein steps (c)-(f) are completed before constructing a new MR pulse sequence in real-time by dynamically connecting the subsequently selected waveform segments and executing the new MR pulse sequence in real-time to generate a new MR image that includes the new image contrast.

11. The method of claim 6, wherein immediately upon occurrence of the subsequently selecting step (g) while the constructing step (c) is in progress, the remainder of the constructing step (c) is completed by constructing a hybrid MR pulse sequence in real-time instead of the MR pulse sequence, wherein the hybrid MR pulse sequence includes at least some of the selected waveform segments and at least some of the subsequently selected waveform segments dynamically connected together.

12. The method of claim 11, wherein the hybrid MR pulse sequence is utilized in steps (d)-(f) to generate a hybrid MR image that includes at least some of the new image contrast.

13. The method of claim 3, wherein the storing step includes storing at least one image contrast waveform segment that is a magnetization preparation mechanism.

14. The method of claim 3, wherein the at least one image contrast waveform segment is selected from a group including an inversion recovery segment, a chemical saturation waveform segment, and a spatial saturation waveform segment.

15. The method of claim 3, wherein the at least one imaging waveform segment is a flow compensation waveform segment.

16. The method of claim 3, wherein the MR pulse sequence comprises at least one imaging waveform segment.

17. The method of claim 3, wherein the selecting step includes selecting at least one image contrast waveform segment and one imaging waveform segment.

18. The method of claim 3, wherein the MR pulse sequence comprises a default base imaging waveform segment stored in the waveform memory when no explicit selection is made in the selecting step (b).

19. The method of claim 3, wherein selecting from the plurality of waveform segments includes selecting more than one image contrast waveform segments.

20. The method of claim 3, wherein constructing the MR pulse sequence includes a sequence controller sequentially accessing at run-time the selected image contrast waveform segments in the waveform memory and the selected imaging waveform segment in the waveform memory.

21. The method of claim 20, wherein constructing the MR pulse sequence includes dynamically connecting the selected imaging waveform segment after the end of the selected image contrast waveform segments.

22. The method of claim 1, further comprising modifying the MR pulse sequence from a modification step selected from a group including modifying an individual gradient amplitude associated with the MR pulse sequence, modifying a radio frequency (RF) amplitude associated with the MR pulse sequence, modifying a pulse width associated with the MR pulse sequence, and modifying a relative timing within the MR pulse sequence.

23. An interactive magnetic resonance (MR) imaging system, comprising:

(a) means for storing a plurality of waveform segments, wherein each of the waveform segments is associated with a distinct memory address and at least one of the waveform segment includes an image contrast mechanism;

(b) means for selecting from the plurality of waveform segments;

(c) means for constructing an MR pulse sequence in real-time by dynamically connecting selected waveform segments at run-time; and

(d) means for acquiring MR data in real-time by execution of the MR pulse sequence to generate a current MR image that includes a desired image contrast.

24. The system of claim 23, wherein each of the waveform segments is comprised of at least one of a radio frequency (RF) waveform segment and a gradient waveform segment.

25. The system of claim 23, wherein the means for storing includes at least one imaging waveform segment and at least one image contrast waveform segment.

26. The system of claim 25, further comprising (e) means for reconstructing the MR data to generate the current MR image in real-time and (f) means for displaying the current MR image.

27. The system of claim 26, further comprising (g) means for subsequently selecting from the plurality of waveform segments while scanning of the current MR image is in progress.

28. The system of claim 27, further comprising means for halting any of the means for constructing, the means of acquiring, the means for reconstructing, and the means for displaying when the means for subsequently selecting is activated.

29. The system of claim 28, further comprising means for constructing a new MR pulse sequence in real-time by dynamically connecting the subsequently selected waveform segments, as specified in the means for subsequently selecting, and means for executing the new MR pulse sequence in real-time to generate a new MR image that includes the new image contrast.

30. The system of claim 29, wherein the means for constructing a new MR pulse sequence is configured to instantaneously access the subsequently selected waveform segments in place of the selected waveform segments, when the MR pulse sequence is being constructed and the subsequently selected waveform segments exist.

31. The system of claim 25, wherein the means for storing includes at least one image contrast waveform segment that is a magnetization preparation mechanism.

32. The system of claim 25, wherein the at least one image contrast waveform segment is selected from a group including an inversion recovery waveform segment, a chemical saturation waveform segment, and a spatial saturation waveform segment.

33. The system of claim 25, wherein the at least one imaging waveform segment is a flow compensation waveform segment.

34. The system of claim 25, wherein the MR pulse sequence comprises at least one imaging waveform segment.

35. The system of claim 25, wherein the MR pulse sequence includes at least one image contrast waveform segment and one imaging waveform segment.

36. The system of claim 25, wherein the MR pulse sequence comprises a default base imaging waveform segment stored in the means for storing when no explicit selection is made by an operator.

37. The system of claim 25, wherein means for selecting from the plurality of waveform segments is configured to permit selecting more than one image contrast waveform segments to construct the MR pulse sequence.

38. The system of claim 25, wherein the means for constructing the MR pulse sequence includes a sequence controller configured to sequentially access at run-time the selected image contrast waveform segments in the means for storing and the selected imaging waveform segment in the means for storing.

39. The system of claim 38, wherein the means for constructing the MR pulse sequence is configured to dynamically connect the selected imaging waveform segment after the end of the selected image contrast waveform segments.

40. The system of claim 23, further comprising means for modifying the MR pulse sequence selected from a group including modifying an individual gradient amplitude associated with the MR pulse sequence, modifying a radio frequency (RF) amplitude associated with the MR pulse sequence, modifying a pulse width associated with the MR pulse sequence, and modifying a relative timing within the MR pulse sequence.

41. The system of claim 23, wherein the means for constructing comprises at least two sequence controllers and the means for storing comprises at least two waveform memories.

42. An interactive magnetic resonance (MR) imaging system, comprising:

a memory configured to store a plurality of waveform segments, wherein each of the waveform segments is associated with a distinct memory address and at least one of the waveform segment includes an image contrast mechanism;

an operator interface configured to permit an operator to select from the plurality of waveform segments;

a sequence controller coupled to the memory and configured to dynamically connect the selected waveform segments at run-time to construct a MR pulse sequence; and

an MR imaging device coupled to the operator interface, memory, and sequence controller and configured to acquire MR data in real-time and generate a current MR image that includes a desired image contrast.

43. The system of claim 42, wherein the operator interface includes an input device selected from a group including a mouse, a joystick, a keyboard, a trackball, a touch screen, a light wand, and a voice control.

44. The system of claim 43, wherein the operator interface includes a plurality of icons on a display means for displaying the available waveform segments.

45. The system of claim 42, wherein the MR imaging device is further configured to reconstruct the MR data to generate the current MR image in real-time and display the current MR image.

46. The system of claim 45, wherein the waveform segments comprise at least one image contrast waveform segment that is a magnetization preparation mechanism.

47. The system of claim 45, wherein the at least one image contrast waveform segment is selected from a group including an inversion recovery waveform segment, a chemical saturation waveform segment, and a spatial saturation waveform segment.

48. The system of claim 45, wherein the at least one imaging waveform segment is a flow compensation waveform segment.

49. The system of claim 45, wherein the MR pulse sequence includes at least one imaging waveform segment.

50. The system of claim 45, wherein the MR pulse sequence comprises a default base imaging waveform segment stored in the memory when no explicit selection is made by an operator.

51. The system of claim 45, wherein the sequence controller is configured to dynamically connect the selected imaging waveform segment after the end of the selected image contrast waveform segments.

52. The system of claim 42, wherein the operator interface is configured to be responsive to subsequent selections of the waveform segments while scanning of the current MR image is in progress.

53. The system of claim 42, wherein the memory includes at least one imaging waveform segment and at least one image contrast waveform segment.

54. The system of claim 42, further comprising an another memory configured to store a portion of the plurality of waveform segments.

55. The system of claim 54, further comprising an another sequence controller to dynamically construct an another MR pulse sequence by appropriately accessing the memory and the another memory while acquisition of MR data relating to the current MR image is in progress.