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US 11,890,086 B2Granted
Magnetic resonance imaging concepts
AssigneeMartin R. Prince
InventorsYi Wang, He Zhu
Life of this patent
Estimating the term…
Abstract
A method for producing multiple temporal frames of a time-resolved contrast enhanced magnetic resonance angiogram from a subject using an MR contrast agent by repeatedly applying RF pulses and sampling data in the corresponding image k-space along spiral trajectories that start at the k-space center and spiral outward toward the k-space edge.
Claims16
A method for producing a time-resolved, three-dimensional contrast enhanced magnetic resonance image, the method comprising:
- enhancing contrast in a tissue;
- applying a first radio frequency (RF) pulse over a scan time;
- sampling a first plurality of resonance data along a first spiral trajectory in a corresponding image spatial frequency domain defined by a plurality of parallel planes, each parallel plane including at least one group of interleaves, the first spiral trajectory corresponding to a first of the plurality of parallel planes and within the group of interleaves, the first spiral trajectory originating at a first center in the first of the plurality of parallel planes and spiraling outward towards a first edge in the first of the plurality of parallel planes;
- applying a second RF pulse over a scan time;
- sampling a second plurality of resonance data along a second spiral trajectory in the corresponding image spatial frequency domain, the second spiral trajectory corresponding to a second of the plurality of parallel planes, the second spiral trajectory originating at a second center in the second of the plurality of parallel planes within the group of interleaves and spiraling outward towards a second edge in the second of the plurality of parallel planes;
- and
- reconstructing the magnetic resonance image using at least the first plurality of resonance data and the second plurality of resonance data, with a frame reconstructed for each group of interleaves wherein for n groups of interleaves the frame time is 1/nth of the scan time;
- and
- wherein:
- the first spiral trajectory has a first sampling density at the first center and a second sampling density at the first edge that is less than the first sampling density;
- the first spiral trajectory radius increases linearly with respect to azimuthal angle at the first center;
- the second spiral trajectory has a third sampling density at the second center and a fourth sampling density at the second edge that is less than the third sampling density;
- and
- wherein the first sampling density and the third sampling density are each a constant sampling density over a predetermined plurality of spatial frequencies,
- the first sampling density decreases non-linearly to the second sampling density.
12 more elements
A method for producing a time-resolved, three-dimensional contrast enhanced magnetic resonance image, the method comprising:
- enhancing contrast in a tissue;
- applying a first radio frequency (RF) pulse over a scan time;
- sampling a first plurality of resonance data along a first spiral trajectory in a corresponding image spatial frequency domain defined by a plurality of parallel planes, each parallel plane including at least one group of interleaves, the first spiral trajectory corresponding to a first of the plurality of parallel planes and within the group of interleaves, the first spiral trajectory originating at a first center in the first of the plurality of parallel planes and spiraling outward towards a first edge in the first of the plurality of parallel planes;
- applying a second RF pulse over a scan time;
- sampling a second plurality of resonance data along a second spiral trajectory in the corresponding image spatial frequency domain, the second spiral trajectory corresponding to a second of the plurality of parallel planes, the second spiral trajectory originating at a second center in the second of the plurality of parallel planes within the group of interleaves and spiraling outward towards a second edge in the second of the plurality of parallel planes;
- and
- reconstructing the magnetic resonance image using at least the first plurality of resonance data and the second plurality of resonance data, with a frame reconstructed for each group of interleaves wherein for n groups of interleaves the frame time is 1/nth of the scan time;
- and
- wherein:
- the first spiral trajectory has a first sampling density at the first center and a second sampling density at the first edge that is less than the first sampling density;
- the first spiral trajectory radius increases linearly with respect to azimuthal angle at the first center;
- the second spiral trajectory has a third sampling density at the second center and a fourth sampling density at the second edge that is less than the third sampling density;
- and
- wherein the first sampling density and the third sampling density are each a constant sampling density over a predetermined plurality of spatial frequencies,
- the third sampling density decreases non-linearly to the fourth sampling density.
12 more elements
Dependencies are inferred from the claim text.