MRI pulse sequence based on Q-space trajectory technique
View Patent ↗Systems and methods capable of improving acquisition times associated with obtaining diffusion-weighted magnetic resonance imaging data are discussed. In aspects, multiple points in q-space can be sampled in a single repetition time (TR). Acquisition time can be further increased using other techniques, such as a radial raster or compressed sensing.
1. A method of applying a magnetic resonance imaging (MRI) pulse sequence, comprising:
applying, via a coil, a single radio frequency (RF) excitation pulse to excite a first set of nuclei associated with a first slice;
applying a first diffusion preparation (DP) to the set of nuclei;
obtaining first diffusion data associated with a first point in q-space via application of a first signal readout;
applying a second DP to the set of nuclei; and
obtaining second diffusion data associated with a second point in q-space via application of a second signal readout, wherein the first point in q-space and the second point in q-space are sampled according to a raster that acquires additional radial lines intersecting a surface of a sphere by oversampling gradient directions.
2. The method of claim 1 , wherein the first diffusion data and the second diffusion data are obtained in response to the single RF excitation pulse and wherein the raster is a radial raster.
3. The method of claim 1 , wherein the first diffusion data and the second diffusion data are obtained according to a spin-echo acquisition technique.
4. The method of claim 1 , wherein the first diffusion data and the second diffusion data are obtained according to a stimulated echo acquisition technique.
5. The method of claim 1 , wherein the first diffusion data and the second diffusion data are obtained according to a hybrid spin-echo stimulated echo acquisition technique.
6. The method of claim 1 , wherein the first point in q-space and the second point in q-space are sampled according to a compressed sensing algorithm.
7. The method of claim 1 , further comprising:
applying a third DP to the set of nuclei; and
obtaining third diffusion data associated with a third point in q-space via application of a third signal readout.
8. The method of claim 7 , further comprising:
applying a fourth DP to the set of nuclei; and
obtaining fourth diffusion data associated with a fourth point in q-space via application of a fourth signal readout.
9. The method of claim 1 , wherein the single RF excitation pulse excites a second set of nuclei associated with a second slice based at least in part on a multi-band excitation technique.
10. The method of claim 1 , wherein an orientation diffusion function (ODF) is determined based at least in part on the first diffusion data and the second diffusion data.
11. The method of claim 1 , wherein the first point in q-space and the second point in q-space are sampled according to a modified Cartesian raster.
12. A magnetic resonance imaging (MRI) system, comprising:
a magnet that generates an external field B 0 ;
an excitation/detection component that implements a q-space trajectory pulse sequence; and
a coil component that obtains information associated with an anatomical region based on a q-space trajectory pulse sequence, wherein the coil component applies a single radio frequency (RF) excitation pulse to excite a first set of nuclei associated with a first slice of the anatomical region, wherein the coil component applies a first diffusion preparation (DP) to the set of nuclei, wherein the coil component obtains first diffusion data associated with a first point in q-space via application of a first signal readout, wherein the coil component applies a second DP to the set of nuclei, and wherein the coil component obtains second diffusion data associated with a second point in q-space via application of a second signal readout, wherein the first point in q-space and the second point in q-space are sampled according to a raster that acquires additional radial lines intersecting a surface of a sphere by oversampling gradient directions.
13. The system of claim 12 , wherein the first diffusion data and the second diffusion data are obtained in response to the single RF excitation pulse and wherein the raster is a radial raster.
14. The system of claim 12 , wherein the coil component obtains the first diffusion data and the second diffusion data according to a spin-echo acquisition technique.
15. The system of claim 12 , wherein the coil component obtains the first diffusion data and the second diffusion data according to a stimulated echo acquisition technique.
16. The system of claim 12 , wherein the coil component obtains the first diffusion data and the second diffusion data according to a hybrid spin-echo stimulated echo acquisition technique.
17. The system of claim 12 , wherein the coil component samples first point in q-space and the second point in q-space according to a compressed sensing algorithm.
18. The system of claim 12 , wherein the coil component applies a third DP to the set of nuclei and obtains third diffusion data associated with a third point in q-space via application of a third signal readout.
19. The system of claim 18 , wherein the coil component applies a fourth DP to the set of nuclei and obtains fourth diffusion data associated with a fourth point in q-space via application of a fourth signal readout.
20. A magnetic resonance imaging (MRI) system, comprising:
means for generating an external field B 0 ;
means for implementing a q-space trajectory pulse sequence; and
means for obtaining information associated with an anatomical region based on a q-space trajectory pulse sequence, wherein the means for obtaining applies a single radio frequency (RF) excitation pulse to excite a first set of nuclei associated with a first slice of the anatomical region, applies a first diffusion preparation (DP) to the set of nuclei, obtains first diffusion data associated with a first point in q-space via application of a first signal readout, applies a second DP to the set of nuclei, and obtains second diffusion data associated with a second point in q-space via application of a second signal readout, wherein the first point in q-space and the second point in q-space are sampled according to a raster that acquires additional radial lines intersecting a surface of a sphere by oversampling gradient directions.