MRI apparatus and method with moving field component

1. Apparatus for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, the apparatus comprising:

a) at least one coil for at least one of transmitting, receiving or transceiving an electromagnetic field;

b) a field component; and,

c) a drive coupled to the field component for moving the field component relative to the imaging region to thereby modify the electromagnetic field.

2. Apparatus according to claim 1 , wherein the field component is at least one of:

a) the at least one coil; and,

b) a shield for partially shielding the at least one coil from the imaging region.

3. Apparatus according to claim 1 , wherein movement of the field component is for modifying at least one of:

a) the electromagnetic field generated by the at least one coil; and,

b) a sensitivity distribution of the at least one coil.

4. Apparatus according to claim 1 , wherein the drive is for at least one of:

a) rotating the field component; and,

b) moving the field component in a plane.

5. Apparatus according to claim 4 , wherein the drive is for rotating the at least one coil about a rotation axis.

6. Apparatus according to claim 5 , wherein a coil axis of the at least one coil is at least one of:

a) aligned with the rotation axis; and,

b) perpendicular to the rotation axis.

7. Apparatus according to claim 6 , wherein the at least one coil is offset to the rotation axis.

8. Apparatus according to claim 4 , wherein the rotation axis is aligned with the imaging region.

9. Apparatus according to claim 1 , wherein the field component comprises a shield, the shield being a slotted shield structure.

10. Apparatus according to claim 1 , wherein the drive comprises at least one of:

a) a motor; and,

b) a turbine.

11. Apparatus according to claim 1 , wherein the drive is at least one of:

a) electric;

b) piezoelectric;

c) pneumatic;

d) hydraulic; and,

e) non-magnetic.

12. Apparatus according to claim 1 , wherein the apparatus comprises sensor for sensing movement of the field component.

13. Apparatus according to claim 1 , wherein the apparatus comprises a processing system for at least one of:

a) controlling movement of the field component; and,

b) determining movement of the field component.

14. Apparatus according to claim 13 , wherein the processing system determines at least one of:

a) a frequency of rotation of the field component; and,

b) a field component movement speed.

15. Apparatus according to claim 13 , wherein the processing system at least one of:

a) analyses measurements at least partially in accordance with the determined field component movement; and,

b) causes an electromagnetic field to be transmitted at least partially in accordance with the determined field component movement.

16. Apparatus according to claim 13 , wherein the processing system controls movement of the field component in accordance with at least one of:

a) a frequency of a transmitted electromagnetic field; and,

b) frequencies of a sequence of transmitted electromagnetic fields.

17. Apparatus according to claim 13 , wherein the processing system triggers a measurement procedure.

18. Apparatus according to claim 1 , wherein the apparatus comprises a processing system for at least one of:

a) causing signals to be applied to the at least one coil; and,

b) determining signals measured in the at least one coil.

19. Apparatus according to claim 18 , wherein the at least one coil is wirelessly coupled to the processing system.

20. Apparatus according to claim 18 , wherein the at least one coil is at least one of inductively and capacitively coupled to the processing system.

21. Apparatus according to claim 13 , wherein the processing system causes measurements to be performed whilst the field component is moving.

22. Apparatus according to claim 1 , wherein the apparatus comprises a plurality of coils, and wherein in use, each coil is used for at least one of:

a) transmitting (a segment of) electromagnetic pulse samples; and,

b) receiving respective decay or echo signals.

23. Apparatus according to claim 1 , wherein the apparatus comprises a plurality of coils arranged to image a three-dimensional (3D) volume of a subject.

24. Apparatus according to claim 23 , wherein each coil is tuned to a different frequency in order to at least one of:

a) transmitting electromagnetic pulse samples to a respective slice of the subject; and,

b) receiving a respective decay or echo signals from a respective slice of the subject.

25. Apparatus according to claim 1 , wherein the apparatus is adapted for at least one of:

a) Multi-nuclear imaging.

b) Multi-nuclear spectroscopy.

26. Apparatus according to claim 1 , wherein the field component comprises a shield, the shield comprising at least one slot.

27. Apparatus according to claim 26 , wherein the slotted shield comprises at least one of:

a) slots of circular or elliptical geometry; and,

b) electronic components for matching resonant properties of the shield to a frequency or impedance of interest.

28. Apparatus according to claim 26 , wherein the shield comprises multiple slots arranged along a direction of multiple slices to be imaged.

29. Apparatus according to claim 28 , wherein the slots are for differentiating the imaged slices by at least one of:

a) different geometrical properties of the slot; and,

b) different resonance frequencies of the slot.

30. Apparatus according to claim 26 , wherein field component comprises a plurality of shields, at least two shields being arranged to move independently.

31. Apparatus according to claim 26 , wherein at least one of a geometry and material properties of the shield vary as function of space.

32. Apparatus according to claim 26 , wherein a geometry of slot(s) in the shield is adjustable.

33. Apparatus according to claim 32 , wherein a processing system controls the geometry of slot(s) depending on a position or movement of the field component.

34. Apparatus according to claim 26 , wherein the shield comprises adjustable electronic circuit components for adjusting electromagnetic properties of the shield.

35. Apparatus according to claim 34 , wherein a processing system adjusts the electronic circuit components.

36. Apparatus according to claim 1 , wherein movement of the shield can be coupled independent of the system electromagnetic coils.

37. Apparatus according to claim 1 , wherein the field component comprises a plurality of coils, at least two coils being arranged to move independently.

38. Apparatus according to claim 37 , wherein the at least two coils are adapted to rotate about different rotation axes.

39. Apparatus according to claim 37 , wherein the at least two coils are adapted to rotate with at least one of:

a) different speeds;

b) different accelerations; and,

c) different orientations.

40. Apparatus according to claim 1 , wherein the apparatus is for reducing a Specific Absorption Rate (SAR) during the imaging procedure.

41. Apparatus according to claim 1 , wherein the apparatus is for modifying the electromagnetic field so that the modified electromagnetic field provides a modulation function for amplitude encoding transmitted or received electromagnetic signals.

42. Apparatus according to claim 1 , wherein the apparatus is for imaging by amplitude modulating/encoding the transmitted or received electromagnetic signals to and from the sample in conjunction with some or without any switching of magnetic field gradient coils.

43. Apparatus according to claim 1 , wherein the field component is mounted on a body, the body being coupled to the drive to thereby cause movement of the body.

44. Apparatus according to claim 1 , wherein the electromagnetic field is at least one of:

a) an RF field; and,

b) non-ionising.

45. Apparatus according to claim 1 , wherein the apparatus comprises a processing system for controlling an imaging rate by controlling at least one of:

a) a rate of movement of the field component; and,

b) a rate of sampling of signals measured in the at least one coil.

46. A method for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, and comprising:

a) at least one coil for at least one of transmitting, receiving or transceiving an electromagnetic field;

b) a field component; and,

c) a drive coupled to the field component, wherein the method comprises moving the field component relative to the imaging region to thereby modify the electromagnetic field.

47. A method according to claim 46 , wherein the method comprises moving the field component to modify at least one of:

a) an electromagnetic field generated by the at least one coil; and,

b) a sensitivity distribution of the at least one coil.

48. A method according to claim 46 , wherein the method comprises, in a processing system, at least one of:

a) controlling movement of the field component; and,

b) determining movement of the field component.

49. A method according to claim 48 , wherein the method comprises, controlling movement of the at least one coil in accordance with measurements being performed.

50. A method according to claim 48 , wherein the at least one coil rotates relative to the imaging region, and wherein the method comprises controlling the rotation speed.

51. A method according to claim 48 , wherein the method comprises controlling electromagnetic signals applied to the at least one coil.

52. A method according to claim 48 , wherein the method comprises, in the processing system, controlling at least one of:

a) a frequency of rotation of the field component; and,

b) a field component movement speed.

53. A method according to claim 48 , wherein the method comprises, in the processing system, determining at least one of:

a) a frequency of rotation of the field component; and,

b) a field component movement speed.

54. A method according to any claim 48 , wherein the method comprises, in the processing system, at least one of:

a) analysing measurements at least partially in accordance with the determined field component movement; and,

b) causing an electromagnetic field to be transmitted at least partially in accordance with the determined field component movement.

55. A method according to claim 48 , wherein the method comprises, in the processing system, controlling movement of the field component in accordance with frequencies of a sequence of transmitted electromagnetic fields.

56. A method according to claim 48 , wherein the method comprises controlling an imaging rate by controlling at least one of:

a) a rate of movement of the field component; and,

b) a rate of sampling of signals measured in the at least one coil.

57. Apparatus for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, the apparatus comprising:

a) at least one coil for at least one of transmitting, receiving or transceiving an electromagnetic field;

b) a field component comprising at least one of:

i) the at least one coil; and,

ii) a shield for partially shielding the at least one coil from the imaging region; and,

c) a drive coupled to the field component for moving the field component relative to the imaging region, during imaging.

58. A method for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, and comprising:

i) at least one coil for at least one of transmitting, receiving or transceiving an electromagnetic field;

ii) a field component comprising at least one of:

(1) the at least one coil; and,

(2) a shield for partially shielding the at least one coil from the imaging region; and,

iii) a drive coupled to the field component, wherein the method comprises moving the field component relative to the imaging region using the drive, during imaging.

59. Apparatus for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, the apparatus comprising:

a) at least one coil for at least one of transmitting, receiving or transceiving an electromagnetic field;

b) a body comprising at least one of:

i) the at least one coil; and,

ii) a shield for partially shielding the at least one coil from the imaging region; and,

c) a drive coupled to the body for moving the body relative to the imaging region, during imaging.

60. A method for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, and comprising:

a) at least one coil for at least one of transmitting, receiving or transceiving an electromagnetic field;

b) a body comprising at least one of:

i) the at least one coil; and,

ii) a shield for partially shielding the at least one coil from the imaging region; and,

c) a drive coupled to the body, and wherein the method comprises moving the body relative to the imaging region using the drive, during imaging.

61. Apparatus for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, the apparatus comprising:

a) a body;

b) at least one coil mounted on the body, the at least one coil being for transmitting or receiving an RF field; and,

c) a drive coupled to the body for rotating the coil relative to the imaging region, during imaging.

62. A method for use in imaging a sample provided in an imaging region of a magnetic resonance imaging system, the method comprising, in a processing system:

a) causing at least one coil to be moved relative to the imaging region during imaging, the at least one coil being for transmitting or receiving an RF field; and,

b) at least one of:

i) causing a sequence of electrical signals to be applied to the coil; and,

ii) determining measurements of electrical signals in the coil.

63. Apparatus for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, the apparatus comprising:

a) at least one field source/sensor for at least one of transmitting, receiving or transceiving an electromagnetic field; and,

b) a drive coupled to the at least one field source/sensor for moving the at least one field source/sensor relative to the imaging region, during imaging.

64. A method for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, and comprising:

a) at least one field source/sensor for at least one of transmitting, receiving or transceiving an electromagnetic field; and,

b) a drive coupled to the at least one field source/sensor, wherein the method comprises moving the at least one field source/sensor relative to the imaging region, during imaging.

65. Apparatus for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, the apparatus comprising:

a) a source for generating an electromagnetic field; and,

b) means for spatially changing the electromagnetic field over time relative to a subject being imaged, during imaging.

66. A method for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, the method comprising:

a) generating an electromagnetic field; and,

b) spatially changing the electromagnetic field over time relative to a subject being imaged during imaging.

67. Apparatus according to claim 1 , wherein the field component is moved during imaging.

68. Apparatus according to claim 1 , wherein the apparatus includes a processing system for interpreting measurements at least partially in accordance with movement of the field component.