Magnetic resonance apparatus

• US 6,046,588 A
• Filed: 11/14/1997
• Issued: 04/04/2000
• Est. Priority Date: 11/15/1996
• Status: Expired due to Term

• Current Assignee: Toshiba Medical Systems Corporation (Canon Inc.)
• Original Assignee: Technology Research Association Of Medical And Welfare Apparatus
• Inventors: Watanabe, Hidehiro
• Primary Examiner(s): ARANA, LOUIS M
• Application Number:
  US08/970,627
• Time in Patent Office: 872 Days
• Field of Search: 324/307, 324/309, 324/300, 324/311, 324/312, 324/314
• US Class Current: 324/307
• CPC Class Codes: G01R 33/4833 using spatially selective excitation of the volume of interest, e.g. selecting non-orthogonal or inclined slices

Abstract

First and second RF pulses are applied to a ¹ H and, simultaneously with or after the application of the second RF pulse, a third RF pulse is applied to the ¹³ C magnetically coupled to the ¹ H, whereby there occurs a first polarization transfer from the spin of the ¹ H to the spin of the ¹³ C. After the first polarization transfer, a fourth RF pulse is applied to the ¹³ C. After the application of the fourth RF pulse, a fifth RF pulse is applied to the ¹ H together with a first slice gradient magnetic pulse. By doing so, those ¹ H spins in the first area are selectively excited, there occurs a second polarization transfer from the spin of the ¹³ C to the spin of the ¹ H and those first MR signals are collected from those spins of the ¹ H in the first area experiencing the first and second polarization transfers. After the collection of a first MR signal, a sixth RF pulse is applied to the ¹ H together with a second slice gradient magnetic field pulse, whereby those ¹ H in a second area are selectively excited, there occurs a third polarization transfer from the spin of the ¹³ C to the spin ¹ H and those second MR signals are collected from the spins of the ¹ H in the second areas experiencing the first and third polarization transfers.

Claims

1. A magnetic resonance apparatus comprises:

first applying means for applying, to a first nuclide of a subject, an RF pulse corresponding to a resonance frequency of the first nuclide;

second applying means for applying, to a second nuclide whose spins are magnetically coupled to the first nuclide, an RF pulse corresponding to a resonance frequency of the second nuclide;

gradient magnetic field applying means for applying a gradient magnetic field;

detecting means for detecting the MR signal from the spins of the first nuclide; and

control means for controlling the first applying means, second applying means, gradient magnetic field applying means and detecting means in accordance with a predetermined pulse sequence, wherein,

in the predetermined pulse sequence,

first and second RF pulses are applied to the first nuclide and, simultaneously with or after application of the second RF pulse, a third RF pulse is applied to the second nuclide magnetically coupled to the spins of the first nuclide, whereby there occurs a first polarization transfer from spins of the first nuclide to spins of the second nuclide;

a fourth RF pulse is applied to the spins of the second nuclide after the first polarization transfer;

after the application of the fourth RF pulse, a fifth RF pulse is applied to the first nuclide together with at least one slice gradient magnetic field pulse, whereby the spins of the first nuclide in the first area are selectively excited, there occurs a second polarization transfer from the spin of the second nuclide to the spin of the first nuclide and those first MR signals are collected from the spins of the first nuclides in the first area experiencing the first and second polarization transfers; and

after the collection of the first MR signals, a sixth RF pulse is applied to the first nuclide together with at least slice gradient magnetic field pulse, whereby the spins of the first nuclides in a second area are selectively excited, there occurs a third polarization transfer from the spin of the second nuclide to the spin of the first nuclide and those second MR signals are collected from the spins of the first nuclides in the second area experiencing the first and third polarization transfers.

2. The apparatus according to claim 1, wherein the gradient magnetic field for phase encoding is applied in at least one of an interval between the first RF pulse and the second RF pulse and interval between the third RF pulse and the fourth RF pulse.

3. The apparatus according to claim 2, wherein at least one of the RF pulses other than the fifth and the sixth RF pulses is applied together with the gradient magnetic field pulse for slice selection.

4. The apparatus according to claim 1, wherein the gradient magnetic field for phase encoding is applied in at least one of an interval between the application of the fifth RF pulse and the detection of the first MR signal and an interval between the application of the sixth RF pulse and the detection of the second MR signal.

5. The apparatus according to claim 4, wherein at least one of the RF pulses other than the fifth and the sixth RF pulses is applied together with the gradient magnetic field pulse.

6. The apparatus according to claim 1, wherein an inversion RF pulse to the first nuclide is applied in at least one of, before the first RF pulse, in an interval between the second RF pulse and the third RF interval and in an interval between the fourth RF pulse and the fifth RF pulse.

7. The apparatus according to claim 6, wherein at least one of the RF pulses other than the fifth and the sixth RF pulses is applied together with the gradient magnetic field pulse for slice selection.

8. The apparatus according to claim 1, wherein at least one of the RF pulses other than the fifth and the sixth RF pulses is applied together with the gradient magnetic field pulse for slice selection.

9. A magnetic resonance apparatus comprising:

first applying means for applying, to a first nuclide of a subject, an RF pulse corresponding to a resonance frequency of the first nuclide;

second applying means for applying, to a second nuclide magnetically coupled to the spins of the first nuclide, an RF pulse corresponding to a resonance frequency of the second nuclide;

gradient magnetic field applying means for applying a gradient magnetic field;

detecting means for detecting the MR signal from the spins of the first nuclide; and

control means for controlling the first applying means, second applying means, gradient magnetic field applying means and detecting means in accordance with a predetermined pulse sequence, whereby

in the predetermined pulse sequence

first and second RF pulses are applied to the first nuclide, a third RF pulse is applied, simultaneously with or after the application of the second RF pulse, to the second nuclide magnetically coupled to the spins of the first nuclide, a refocusing RF pulse to the first nuclide and an inversion RF pulse to the second nuclide are applied at an interval between the first RF pulse and the second RF pulse, whereby there occurs a first polarization transfer from the spins of the first nuclide to the spins of the second nuclide;

a fourth RF pulse is applied to the second nuclide after the first polarization transfer;

after the application of the fourth RF pulse, a fifth RF pulse to the first nuclide is applied together with at least one of slice gradient magnetic field pulses, whereby the spins of the first nuclide in a first area are selectively excited, there occurs a second polarization transfer from the spin of the second nuclide to the spin of the first nuclide and those first MR signals are collected from those spins of the first nuclides in the first area experiencing the first and second polarization transfers; and

after the collection of the first MR signals, a sixth RF pulse to the first nuclide is applied together with at least one of the slice gradient magnetic field pulses, whereby the spins of the first nuclide in a second area are selectively are excited, there occurs a third polarization transfer from the spin of the second nuclide to the spin of the first nuclide and those second MR signals are collected from those first nuclides in a second area experiencing the first and third polarization transfers.

10. The apparatus according to claim 9, wherein the gradient magnetic field for phase encoding is applied both in at least one of an interval between the first RF pulse and the second RF pulse and interval between the third RF pulse and the fourth RF pulse and in an interval in which the refocusing RF pulse and inversion RF pulse are not applied.

11. The apparatus according to claim 10, wherein at least one of the RF pulses other than the fifth and the sixth RF pulse and refocusing RF pulse is applied together with the gradient magnetic field pulse for slice selection.

12. The apparatus according to claim 9, wherein the gradient magnetic field for phase encoding is applied in at least one of an interval between the application of the fifth RF pulse and the detection of the first MR signal and interval between the application of the sixth RF pulse and the detection of the second MR signal.

13. The apparatus according to claim 12, wherein at least one of the RF pulses other than the fifth and the sixth RF pulse and refocusing RF pulse is applied together with the gradient magnetic field pulse for slice selection.

14. The apparatus according to claim 9, wherein an inverted pulse to the first nuclide is applied in at least one of below the first RF pulse, in an interval between the 2RF pulse and the third RF pulse and in an interval between the fourth RF pulse and the fifth RF pulse.

15. The apparatus according to claim 14, wherein at least one of the RF pulses other than the fifth and the sixth RF pulse is applied together with the gradient magnetic field pulse for slice selection.

16. The apparatus according to claim 9, wherein at least one of the first RF pulse, second RF pulses other than the fifth and the sixth RF pulses and refocusing RF pulse is applied together with the gradient magnetic field pulse for slice selection.

17. A magnetic resonance apparatus comprising:

first applying means for applying, to a first nuclide of a subject, an RF pulse corresponding to a resonance frequency of the first nuclide;

second applying means for applying, to a second nuclide magnetically coupled to the spins of the first nuclide, an RF pulse corresponding to a resonance frequency of the second nuclide;

gradient magnetic field applying means for applying a gradient magnetic field;

detecting means for detecting the MR signal from the spins of the first nuclide; and

control means for controlling the first applying means, second applying means, gradient magnetic field applying means and detecting means in accordance with a predetermined pulse sequence, whereby

in the predetermined pulse sequence

first and second RF pulses are applied to the first nuclide and a third RF pulse is applied, simultaneously with or after the application of the second RF pulse, to the second nuclide magnetically coupled to the spins of the first nuclide, whereby there occurs a first polarization from the spins of the first nuclide to the spins of the second nuclide;

after the first polarization transfer, a fourth RF pulse is applied to the second nuclide;

the RF pulse to the first nuclide is applied at an interval between the third RF pulse and the fourth RF pulse;

after the application of the fourth RF pulse, a fifth RF pulse to the first nuclide is applied together with at least one slice gradient magnetic field pulse, whereby the spins of the first nuclide in the first area are selectively excited, there occurs a second polarization transfer from the spins of the second nuclide to the spins of the first nuclide and those first MR signals are collected from those spins of the first nuclides in the first area experiencing the first and second polarization transfers; and

after the collection of the first MR signals, a sixth RF pulse to the first nuclide is applied together with at least one slice gradient magnetic field pulse, whereby the spins of the first nuclides in the second area are selectively excited, there is a third polarization transfer from the spins of the second nuclide to the spins of the first nuclide and those second MR signals are collected from those spins of the first nuclides in the second area experiencing the first and second polarization transfers.

18. The apparatus according to claim 17, wherein the gradient magnetic field for phase encoding is applied both in at least one of an interval between the first RF pulse and the second RF pulse and interval between the third RF pulse and fourth pulse and in a period in which the refocusing and inversion RF pulses are not applied.

19. The apparatus according to claim 18, wherein at least one of the first and second RF pulses other than the fifth and the sixth RF pulse is applied together with the gradient magnetic field pulse for slice selection.

20. The apparatus according to claim 17, wherein the gradient magnetic field for phase encoding is applied in at least one of an interval between the application of the fifth RF pulse and the detection of the first MR signal and interval between the application of the sixth RF pulse and the detection of the second MR signal.

21. The apparatus according to claim 20, wherein at least one of the RF pulses other than the fifth and the sixth RF pulse is applied together with a gradient magnetic field pulse for slice selection.

22. The apparatus according to claim 17, wherein an inversion RF pulse is applied to the first nuclide in at least one of before the first RF pulse, in an interval of the second RF pulse and the third RF pulse and in an interval between the fourth RF pulse and the fifth RF pulse.

23. The apparatus according to claim 22, wherein at least one of the first RF pulse and second RF pulses other than the fifth and the sixth RF pulses is applied together with a gradient magnetic field pulse for slice selection.

24. The apparatus according to claim 17, wherein at least one of the first and second RF pulses other than the fifth and the sixth RF pulses is applied together with a gradient magnetic field pulse for slice selection.

25. A magnetic resonance apparatus comprising:

first applying means for applying, to a first nuclide of a subject, an RF pulse corresponding to a resonance frequency of the first nuclide;

second applying means for applying, to a second nuclide magnetically coupled to the spins of the first nuclide, an RF pulse corresponding to a resonance frequency of the second nuclide;

gradient magnetic field applying means for applying a gradient magnetic field;

detecting means for detecting the MR signal from the spins of the first nuclide; and

control means for controlling the first applying means, second applying means, gradient magnetic field applying means and detecting means in accordance with a predetermined pulse sequence, whereby

in the predetermined pulse sequence

first and second RF pulses are applied to the first nuclide, a third RF pulse is applied, simultaneously with or after the application of the second RF pulse, to the second nuclide magnetically coupled to the spins of the first nuclide, and a refocusing RF pulse to the first nuclide and inversion RF pulse to the second nuclide are applied in an interval between the first RF pulse and the second RF pulse, whereby there occurs a first polarization transfer from the spins of the first nuclide to the spins of the second nuclide;

after the first polarization transfer, a fourth RF pulse is applied to the second nuclide;

the RF pulse is applied to the first nuclide in an interval between the third RF pulse and the fourth RF pulse;

after the application of the fourth RF pulse, a fifth RF pulse is applied to the first nuclide together with at least one slice gradient magnetic field pulse, whereby the spins of the first nuclide in the first area are selectively excited, there occurs a second polarization transfer from the spins of the second nuclide to the spins of the first nuclide and those first MR signals are collected from the spins of the first nuclide in the first area experiencing first and second polarization transfers; and

after the collection of the first MR signals, a sixth RF pulse is applied to the first nuclide together with at least one slice gradient magnetic field pulse, whereby the spins of the first nuclide in a second area are selectively excited, there occurs a third polarization transfer from the spins of the second nuclide to the spins of the first nuclide and those second MR signals are collected from those spins of the first nuclides in the second area experiencing the first and third polarization transfers.

26. The apparatus according to claim 25, wherein a gradient magnetic field for phase encoding is applied both in at least one of an interval between the first RF pulse and the second RF pulse and interval between the third RF pulse and the fourth RF pulse and in an interval in which the refocusing RF pulse and inversion RF pulse are not applied.

27. The apparatus according to claim 26, wherein at least one of the pulses other than the fifth and the sixth RF pulses is applied together with a gradient magnetic pulse for slice selection.

28. The apparatus according to claim 25, wherein a gradient magnetic field for phase encoding is applied in at least one of an interval between the application of the fifth RF pulse and the detection of the first MR signal and interval between the application of the sixth RF pulse and the detection of the second MR signal.

29. The apparatus according to claim 28, wherein at least one of the RF pulses other than the fifth and the sixth RF pulses is applied together with a gradient magnetic field pulse for slice.

30. The apparatus according to claim 25, wherein an inversion pulse is applied to the first nuclide in at least one of before the first RF pulse, in an interval between the second RF pulse and the third RF pulse and in an interval between the fourth RF pulse and the fifth RF pulse.

31. The apparatus according to claim 30, wherein at least one of the pulses other than the fifth and the sixth RF pulses is applied together with a gradient magnetic field pulse for slice selection.

32. The apparatus according to claim 25, wherein at least one of the pulses other than the fifth and the sixth RF pulses is applied together with a gradient magnetic field pulse for slice selection.

33. A magnetic resonance apparatus comprising:

first applying means for applying, to a first nuclide of a subject, an RF pulse corresponding to a resonance frequency of the first nuclide;

second applying means for applying, to a second nuclide, an RF pulse;

gradient magnetic field applying means for applying a gradient magnetic field to the subject;

detecting means for detecting the MR signal from the first nuclide; and

control means for controlling the first applying means, second applying means, gradient magnetic field applying means and detecting means in accordance with a predetermined pulse sequence, whereby

in the predetermined pulse sequence

at least one of an RF pulse to the first nuclide and RF pulse to the second nuclide is applied to create a longitudinal spin order state of the first and second nuclides magnetically coupled to each other and, after this state, a first RF pulse to the first nuclide is applied simultaneously with at least one slice gradient magnetic field pulse, whereby the spins of the first nuclides in a first area are selectively excited and those first MR signals are collected from those spins of the first nuclides magnetically coupled to the spins of the second nuclide in the first area; and

after the collection of the first MR signals, a second RF pulse to the first nuclide is applied simultaneously with at least one slice gradient magnetic field pulse, whereby those spins in the longitudinal spin order state of the first and second nuclides in the second area are excited and those second MR signals are collected from those spins of the first nuclides magnetically coupled to the spins of the second nuclides in the second area.