Automatic coil element selection in large MRI coil arrays
First Claim
1. A method of imaging a subject, comprising the steps of:
- providing a magnetic resonance imaging system having a magnetic field;
providing a plurality of receive coils movable with respect to the magnetic field;
providing at least one sensor having a known position with respect to the plurality of coils;
sensing the magnetic field with the at least one sensor;
selecting at least one receive coil of the plurality of receive coils in accordance with the sensing of the magnetic field; and
enabling the selected at least one receive coil to form an image of a region of the subject.
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Accused Products
Abstract
A method of imaging a subject in an imaging system having a magnetic field and a plurality of receive coils movable with respect to the magnetic field includes sensing the magnetic field by means of at least one sensor having a known position with respect to the subject. At least one of the plurality of receive coils is selected in accordance with the sensing, and is enabled to form an image of the subject. The sensor may include a plurality of sensor coils disposed at differing locations within the magnetic field to sense the differing field amplitudes and/or phases thereof. The differing field intensities cause differing voltage amplitudes and/or phases to be induced on the sensor coils. The differing voltage amplitudes and/or phases are compared to determine the relative positions of the magnetic isocenter of the system and the receive coils to be enabled. Thus, a method for magnetic resonance imaging of a subject in an imaging system having a static magnetic field [B0], a selectively applied gradient magnetic field [B1], a selectively applied transmit excitation radio frequency magnetic field [RF B1], and a plurality of simultaneous data acquisition channels is taught wherein the location of a phased array or other multiple element receive coil and the subject patient with respect to the imaging center of the host magnetic resonance imaging system is determined by sensing the characteristics of one of the magnetic fields.
104 Citations
56 Claims
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1. A method of imaging a subject, comprising the steps of:
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providing a magnetic resonance imaging system having a magnetic field;
providing a plurality of receive coils movable with respect to the magnetic field;
providing at least one sensor having a known position with respect to the plurality of coils;
sensing the magnetic field with the at least one sensor;
selecting at least one receive coil of the plurality of receive coils in accordance with the sensing of the magnetic field; and
enabling the selected at least one receive coil to form an image of a region of the subject. - View Dependent Claims (2, 3, 4, 5)
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6. A magnetic resonance imaging system for imaging a subject, the imaging system comprising:
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a plurality of receive coils movable with respect to a magnetic field for imaging anatomical regions of the plurality of coils;
at least one sensor having a known position with respect to the subject for sensing the magnetic field; and
a switching device for selecting at least one of the plurality of receive coils in accordance with the sensing of the magnetic field by the at least one sensor. - View Dependent Claims (7)
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8. A method of imaging a subject, comprising the steps of:
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setting an imaging subject in close proximity to a plurality of receive coil elements;
applying a magnetic field to the imaging subject, the receive coil elements and the subject being movable relative to the magnetic field;
sensing the magnetic field with at least one sensor having a known position with respect to the plurality of receive coil elements;
selecting at least one receive coil element element from the plurality of receive coil elements in accordance with the sensing of the magnetic field; and
enabling the selected at least one receive coil elements to form an image of a region of the subject in response to being selected. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
disposing a plurality of sensors at select positions corresponding to the differing field amplitudes; and
sensing the differing field amplitudes.
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11. The method of claim 10 wherein the step of selecting comprises selecting at least one receive coil according to a comparison of the sensed differing field amplitudes.
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12. The method of claim 11 wherein the magnetic field defines an imaging volume having an isocenter, the differing field amplitudes being distributed about the isocenter, wherein:
the step of selecting comprises the step of selecting a plurality of receive coil elements that are centered about the isocenter.
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13. The method of claim 12, further comprising the step of determining a number of the plurality of receive coil elements to be selected in accordance with the sensing.
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14. The method of claim 12 wherein the imaging system comprises externally provided selection information, and further comprising the step of determining a number of the plurality of receive coil elements to be selected in accordance with the externally provided selection information.
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15. The method of claim 11 wherein the magnetic field has differing phases at differing locations and the plurality of sensors and further comprising the step of disposing the plurality of sensors at differing locations to sense the differing phases.
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16. The method of claim 8 wherein the step of selecting comprises selecting a plurality of receive coil elements in accordance with the sensing.
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17. The method of claim 8, further comprising the step of electrically coupling the selected at least one receive coil to a scanner having at least one scanner input.
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18. The method of claim 17 wherein the step of electrically coupling the selected at least one receive coil comprises the step of coupling at least one of N receive coil elements, to at least one of M scanner inputs, and N>
- M.
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19. The method of claim 17 herein the step of selecting further comprises the step of selecting a number of receive coil elements that is less than or equal to M.
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20. The method of claim 8 wherein the step of applying the magnetic field includes the step of applying a gradient B1 field, and wherein the step of sensing comprises the step of sensing the gradient B1 field.
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21. The method of claim 8 wherein the step of applying the magnetic field includes the step of applying an RF B1 field, and wherein the step of sensing comprises the step of sensing the RF B1 field.
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22. The method of claim 8 wherein the step of applying the magnetic field includes the step of applying a static magnetic B0 field, and wherein the step of sensing comprises the step of sensing the static magnetic B0 field.
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23. The method of claim 8 further comprising the step of arranging the plurality of receive coil elements in pairs of receive coil elements and providing the pairs of receive coil elements with corresponding sensors.
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24. The method of claim 8 further comprising the step of arranging the plurality of receive coil elements in pairs of coil elements comprising quadrature coils.
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25. The method of claim 8 wherein the step of sensing comprises the step of sensing a selectively applied gradient B1 magnetic field with at least one sensor.
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26. The method of claim 8 wherein the step of sensing comprises the step of sensing a transmit B1 magnetic field with at least one sensor.
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27. A magnetic resonance imaging system comprising:
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a plurality of receive coil elements movable with respect to a magnetic field, the magnetic field operable to generate magnetic energy in a subject, the plurality of receive coil elements operable to receive the magnetic energy when the subject is set in proximity to the plurality of receive coil elements;
at least one sensor having a known position relative to the plurality of receive coil elements, the sensor operable to sense the magnetic field; and
a switching device coupled to the at least one sensor, the switching device operable to select at least one of the plurality of receive coil elements in accordance with the sensing of the magnetic field by the at least one sensor. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43)
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44. A magnetic resonance imaging system comprising:
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a plurality of receive coil elements movable with respect to a magnetic field, the magnetic field operable to generate magnetic energy in a subject, the plurality of receive coil elements operable to receive the magnetic energy when the subject is set in proximity to the plurality of receive coil elements;
a sensor device for determining the position of the subject within the magnetic field, the sensor device comprising at least two sensors movable within the magnetic field for sensing the amplitudes of the magnetic field at differing locations therein and for determining the position of the subject within the magnetic field in accordance with the amplitudes sensed by the at least two sensors;
a sensing signal generated by the sensor device, the sensing signal indicative of the position of the subject withing the magnetic field; and
a switching device coupled to the sensor device, the switching device operable to select at least one of the plurality of receive coil elements in accordance with the sensing signal. - View Dependent Claims (45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55)
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56. A method of imaging a subject, comprising the steps of:
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setting an imaging subject in close proximity to N receive coil elements, where N>
1;
applying a magnetic field to the imaging subject, the receive coil elements and the subject being movable relative to the magnetic field;
sensing the magnetic field with at least one sensor having a known position with respect to the N receive coil elements;
selecting fewer than N of the receive coil elements in accordance with the sensing of the magnetic field; and
enabling the selected fewer than N receive coil elements to form an image of a region of the subject in response to being selected;
wherein the selected fewer than N receive coil elements represent an optimum combination of coil elements selected to produce a best image.
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Specification