Fast Prospective Motion Correction For MR Imaging
First Claim
1. A magnetic resonance (MR) imaging system for generating a real-time motion-corrected MR image of a region of interest, comprising:
- a pulse sequence generator configured to insert a navigator sequence into each of a plurality of MR imaging sequences used to obtain the MR image to obtain navigator image data;
an image processor arrangement configured to reconstruct a navigator image based on the navigator data; and
a processing arrangement configured to determine motion of the region of interest by comparing the navigator image with a previous navigator image, and to modify a subsequent imaging sequence based on the determined motion,wherein the navigator image data is obtained using a 2D echo-planar imaging technique comprising between 1 and 10 shots;
wherein each shot is configured to simultaneously excite between 2 and 12 slices of the navigator image;
wherein a field of view of the navigator image is between 100 mm and 500 mm in each direction within each slice of the navigator image and between 20 mm and 500 mm in a direction perpendicular to the navigator slices; and
wherein a spatial resolution for the navigator image in each direction is between 3 mm and 10 mm; and
wherein a total time for obtaining the navigator image data is less than 100 ms.
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Accused Products
Abstract
A magnetic resonance (MR) method and system are provided for generating real-time prospective motion-corrected images using fast navigators. The real-time motion correction is achieved by using a 2D EPI navigator that is obtained using a simultaneous multi-slice blipped-CAIPI technique. The navigator parameters such as field of view, voxel size, and matrix size can be selected to facilitate fast acquisition while providing information sufficient to detect rotational motions on the order of several degrees or more and translational motions on the order of several millimeters or more. The total time interval for obtaining and reconstructing navigator data, registering the navigator image, and providing feedback to correct for detected motion, can be on the order of about 100 ms or less. This prospective motion correction can be used with a wide range of MR imaging techniques where the pulse sequences do not have significant intervals of “dead” time.
23 Citations
20 Claims
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1. A magnetic resonance (MR) imaging system for generating a real-time motion-corrected MR image of a region of interest, comprising:
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a pulse sequence generator configured to insert a navigator sequence into each of a plurality of MR imaging sequences used to obtain the MR image to obtain navigator image data; an image processor arrangement configured to reconstruct a navigator image based on the navigator data; and a processing arrangement configured to determine motion of the region of interest by comparing the navigator image with a previous navigator image, and to modify a subsequent imaging sequence based on the determined motion, wherein the navigator image data is obtained using a 2D echo-planar imaging technique comprising between 1 and 10 shots; wherein each shot is configured to simultaneously excite between 2 and 12 slices of the navigator image; wherein a field of view of the navigator image is between 100 mm and 500 mm in each direction within each slice of the navigator image and between 20 mm and 500 mm in a direction perpendicular to the navigator slices; and wherein a spatial resolution for the navigator image in each direction is between 3 mm and 10 mm; and wherein a total time for obtaining the navigator image data is less than 100 ms. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for generating a real-time motion-corrected magnetic resonance (MR) image of a region of interest, comprising the steps of:
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(a) providing a plurality of pulse sequences to obtain image data from the region of interest that can be used to generate the MR image; (c) inserting a 2D multi-slice EPI navigator sequence within each of the plurality of pulse sequences; (d) generating a navigator image of a portion of the region of interest based on the navigator sequence; (e) determining a motion of the region of interest based on a comparison of the navigator image with a previous navigator image; (f) modifying properties of a subsequent pulse sequence based on the determined motion to correct for motion effects; and (h) generating the motion-corrected MR image of the region of interest based on the image data, wherein the navigator image is obtained using a 2D echo-planar imaging technique comprising between 1 and 10 shots; wherein each shot is configured to simultaneously excite between 2 and 12 slices of the navigator image; wherein a field of view is between 100 and 500 mm in each direction within each slice of the navigator image and between 20 and 500 mm in a direction perpendicular to the navigator slices; and wherein a spatial resolution for the navigator image in each direction is between 3 mm and 10 mm; and wherein a total time for obtaining the navigator image data is less than 100 ms. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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Specification