Motion compensation for magnetic resonance imaging
First Claim
1. A method for acquiring MR image data for an object and performing motion compensation on the MR image data, the method comprising:
- a) generating a uniform magnetic field through the object;
b) generating magnetic field gradients for imaging a portion of the object and an RF excitation field for evoking NMR response signals from the object;
c) generating a plurality of navigator waveforms for evoking a corresponding plurality of navigator echoes from the portion of the object while the object is being imaged;
d) sampling the NMR response signals and the plurality of navigator echoes; and
,e) processing the plurality of navigator echoes by determining a subset of similar navigator echoes according to a similarity metric and removing rigid-body translations from the sampled NMR response signals associated with the subset of similar navigator echoes; and
f) displaying MR images generated based on the motion compensated MR image data.
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Accused Products
Abstract
An MRI system and method for acquiring motion-compensated MR image data of an object. The MRI system includes an MRI device for generating a uniform magnetic field through the object, magnetic field gradients for imaging a portion of the object and an RF excitation field for evoking NMR response signals from the object; a computer for controlling the operation of the MRI system; a motion compensation module for generating a plurality of navigator waveforms for evoking a corresponding plurality of navigator echoes from the portion of the object while the object is being imaged, and processing the plurality of navigator echoes by determining a subset of similar navigator echoes and removing rigid-body translation from the NMR response signals associated with the subset of similar navigator echoes; and, interface circuitry for generating the magnetic gradient, RF and navigator waveforms and sampling the NMR response signals and the plurality of navigator echoes.
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Citations
28 Claims
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1. A method for acquiring MR image data for an object and performing motion compensation on the MR image data, the method comprising:
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a) generating a uniform magnetic field through the object; b) generating magnetic field gradients for imaging a portion of the object and an RF excitation field for evoking NMR response signals from the object; c) generating a plurality of navigator waveforms for evoking a corresponding plurality of navigator echoes from the portion of the object while the object is being imaged; d) sampling the NMR response signals and the plurality of navigator echoes; and
,e) processing the plurality of navigator echoes by determining a subset of similar navigator echoes according to a similarity metric and removing rigid-body translations from the sampled NMR response signals associated with the subset of similar navigator echoes; and f) displaying MR images generated based on the motion compensated MR image data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An MRI system for acquiring MR image data for an object and performing motion compensation on the MR image data, the MRI system comprising:
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a) an MRI device for generating a uniform magnetic field through the object, magnetic field gradients for imaging a portion of the object and an RF excitation field for evoking NMR response signals from the object; b) a computer for controlling the operation of the MRI system; c) a motion compensation module for generating a plurality of navigator waveforms for evoking a corresponding plurality of navigator echoes from the portion of the object that is being imaged, and processing the plurality of navigator echoes by determining a subset of similar navigator echoes and removing rigid-body translation from the NMR response signals associated with the subset of similar navigator echoes; and
,d) interface circuitry for generating waveforms in response to instructions received from the computer and the motion compensation module and sending the waveforms to the MRI device for producing the magnetic field gradients, the RF excitation field and the navigator waveforms, the interface circuitry further being configured for sampling the NMR response signals and the plurality of navigator echoes. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A method for performing motion compensation on MR image data, the MR image data including NMR response signals and corresponding navigator echoes, the method comprising:
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a) selecting a similarity metric; b) applying the similarity metric to the navigator echoes to determine a subset of similar navigator echoes; and c) removing rigid-body translations from the NMR response signals associated with the subset of similar navigator echoes; and
d) displaying MR images generated based on the motion compensated MR image data. - View Dependent Claims (25, 26, 27)
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28. A computer program product comprising a computer readable medium embodying a program code means executable by a processor for carrying out a method for performing motion compensation on MR image data, the MR image data including NMR response signals and corresponding navigator echoes, the method comprising:
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a) selecting a similarity metric; b) applying the similarity metric to the navigator echoes to determine a subset of similar navigator echoes; c) removing rigid-body translations from the NMR response signals associated with the subset of similar navigator echoes; and d) displaying MR images generated based on the motion compensated MR image data.
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Specification