PARALLEL TRANSMISSION BY SPIN DYNAMIC FINGERPRINTING

• US 20160282436A1
• Filed: 11/14/2014
• Published: 09/29/2016
• Est. Priority Date: 11/15/2013
• Status: Active Grant

• Current Assignee: New York University
• Original Assignee: New York University
• Inventors: Cloos, Martijn Anton Hendrik
• Granted Patent: US 10,670,682 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: G01R 33/246 Spatial mapping of the RF magnetic field B1
• CPC Class Codes: G01R 33/4828 Resolving the MR signals of different chemical species, e.g. water-fat imaging
• CPC Class Codes: G01R 33/4835 of multiple slices
• CPC Class Codes: G01R 33/50 based on the determination of relaxation times , e.g. T1 measurement by IR sequences; T2 measurement by multiple-echo sequences
• CPC Class Codes: G01R 33/5602 by filtering or weighting based on different relaxation times within the sample, e.g. T1 weighting using an inversion pulse
• CPC Class Codes: G01R 33/5608 Data processing and visualization specially adapted for MR, e.g. for feature analysis and pattern recognition on the basis of measured MR data, segmentation of measured MR data, edge contour detection on the basis of measured MR data, for enhancing measured MR data in terms of signal-to-noise ratio by means of noise filtering or apodization, for enhancing measured MR data in terms of resolution by means for deblurring, windowing, zero filling, or generation of gray-scaled images, colour-coded images or images displaying vectors instead of pixels image data processing or generation, in general G06T
• CPC Class Codes: G01R 33/5612 Parallel RF transmission, i.e. RF pulse transmission using a plurality of independent transmission channels
• CPC Class Codes: G01R 33/56545 caused by finite or discrete sampling, e.g. Gibbs ringing, truncation artefacts, phase aliasing artefacts

Abstract

A general framework is for signal encoding in MRF that enables simultaneous transmit and receive encoding to accelerate the acquistion process, or improve the fidelity of the final image/parameter-map per unit scan time. The proposed method and systems capitalize on the distinct spatial variations in the sensitivity profile of each transmit-coil to reduce the acquistion time, and/or improve the fidelity of the final parameter-map per unit time.

Claims

1. A system for whole body magnetic resonance imaging comprising:

a magnet;

a plurality of radio frequency transmitters in communication with a computer system each independently driving a coil element wherein each of the plurality of independently driven coil elements produces a set of distinct B1+ distributions.

2. The system of claim 1, wherein each of the plurality of independently driven coil elements are positioned relative to each other and a volume of interest whereby every voxel within the volume of interest is exposed to electromagnetic energy from at least one of the coils.

3. The system of claim 1, wherein the plurality of independently driven coil elements are configured for parallel transmit.

4. The system of claim 1, wherein the magnet is configured to generate a greater than 7 Tesla magnetic field.

5. The system of claim 1, wherein the plurality of independently driven coil elements include groups of coil elements.

6. A nontransitory computer-readable memory having instructions thereon, the instructions comprising:

instructions for transmitting a radio frequency signal from a plurality of coil elements, where each of the plurality of coil elements transmits an independent radio frequency signal producing a distinct B1+;

instructions for receiving induced radio frequency signals from a material; and

instructions for identifying the material based upon the closest match utilizing the distinct B1+ associated with each of the plurality of coil elements.

7. The nontransitory computer-readable memory of claim 6, further including instructions for interleaving transmit sensitivities associated with each of the plurality of coil elements.

8. The nontransitory computer-readable memory of claim 6, further comprising instructions for defining a volume of interest whereby every voxel within the volume of interest is exposed to electromagnetic energy from at least one of the coils.

9. A method for identifying a material comprising:

transmitting a radio frequency signal from a plurality of coil elements, where each of the plurality of coil elements transmits an independent radio frequency signal producing a distinct B1+;

receiving induced radio frequency signals from a material; and

identifying the material based upon the closest match utilizing the distinct B1+ associated with each of the plurality of coil elements.

10. The method of claim 9 further including interleaving transmit sensitivities associated with each of the plurality of coil elements.

11. The method of claim 9 defining a volume of interest whereby every voxel within the volume of interest is exposed to electromagnetic energy from at least one of the coils.

12. The method of claim 9, further comprising inducing a greater than 7 Tesla magnetic field.

13. The method of claim 10, further comprising compressing the interleaved transmit sensitivities.

14. The method of claim 10, further comprising determining a delay and providing for at least one delay during the receiving of the induced radio frequency signals from the material.

15. A system for magnetic resonance fingerprinting in the presence of strong B₁⁺(r) non-uniformities comprising:

a processor; and

a tangible computer-readable medium operatively connected to the processor and including computer code configured to;

receive magnetic resonance information regarding a material including B1+ information;

search a database having an MRI library for a closest match to the received magnetic resonance information; and

identify the material based upon the closest match.

16. The system of claim 15, further comprising computer code configured for limiting the searching of the MRI library based on premeasured B1+ information.

17. The system of claim 15, wherein the magnetic resonance information corresponds to a plurality of voxels.

18. The system of claim 15, further comprising computer code configured to, for every voxel of the plurality of voxels, searching the MRI library for two library elements that best match the MRI resonance information.

19. The system of claim 15, further comprising computer code configured to search the MRI library for elements matching compressed MRI resonance information.

20. The system of claim 15, further comprising computer code configured to insert at least one delay during the receiving of the magnetic resonance information regarding the material.