Magnetic field probe for MRI with a fluoroelastomer or a solution of a fluorine-containing compound

Patent metadata

Field	Value
Publication number	US-10416260-B2
Application number	US-201214351753-A
Country	US
Kind code	B2
Filing date	Oct 12, 2012
Priority date	Oct 17, 2011
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

A magnetic field within a magnetic resonance (MR) imaging system ( 300 ) is measured. The MR system includes a magnet ( 304 ) with an imaging zone ( 308 ), a radio-frequency transceiver ( 316 ), and a magnetic field probe ( 322 ) located within the imaging zone. The magnetic field probe includes a fluorine sample ( 404 ) including any one of the following: a fluoroelastomer ( 700 ), a fluorine containing ionic liquid ( 600 ), and a solution of a fluorine containing compound. The field probe further includes an antenna ( 406 ) for manipulating the magnetic spins of the fluorine sample and for receiving fluorine magnetic resonance data from the fluorine sample. The antenna is connected to the radio-frequency transceiver. The method includes acquiring ( 100, 200 ) the fluorine magnetic resonance data using the magnetic resonance imaging system and calculating ( 102, 206 ) a magnetic field strength ( 344 ) using the fluorine magnetic resonance data.

First claim

The invention claimed is:

1. A method of measuring a magnetic field within a magnetic resonance imaging system,
the magnetic resonance imaging system including a magnet for providing an imaging zone, a radio-frequency transceiver, and a magnetic field probe, wherein the magnetic field probe is located within the imaging zone, wherein the magnetic field probe comprises a fluorine sample including an 19 F active nucleus, the fluorine sample includes an 19 F containing ionic liquid including a fluorine relaxation agent, wherein the fluorine sample contains ionic liquid is 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide or 1-Butyl-4-methylpyridinium tetrafluoroborate, and wherein the fluorine relaxation agent is manganese trifluoromethanesulfonate or gadolinium trifluoromethanesulfonate, wherein the magnetic field probe further comprises an antenna for manipulating the magnetic spins of the fluorine sample and for receiving fluorine magnetic resonance data from the fluorine sample, and wherein the antenna is connected to the radio-frequency transceiver, wherein the method comprises the steps of:
acquiring the fluorine magnetic resonance data using the magnetic resonance imaging system; and
calculating a magnetic field strength using the fluorine magnetic resonance data.

2. The method of claim 1 , wherein the 19 F active nucleus is in any one of the following: bis(trifluoromethylsulfonyl)imide, tetrafluoroborate, hexafluorophosphate, tetrafluoroaluminate, hexafluoroantimonate, hexafluoroarsenate, bis(trifluoromethane)sulfonimide, and tris(trifluoromethylsulfonyl)methide.

3. The method of claim 2 , wherein the method further comprise the steps of:
acquiring image magnetic resonance data from a subject in the imaging zone using the magnetic resonance imaging system;
calculating corrected magnetic resonance data using the magnetic field strength and the image magnetic resonance data; and
reconstructing an image of the subject from the corrected magnetic resonance data.

4. A method of measuring a magnetic field within a magnetic resonance imaging system,
the magnetic resonance imaging system comprising a magnet for providing an imaging zone, a radio-frequency transceiver, and a magnetic field probe located within the imaging zone, wherein the magnetic field probe comprises an active nucleus, wherein the active nucleus includes fluorine 19 ( 19 F) in a fluoroelastomer, wherein the magnetic field probe further comprises an antenna for manipulating the magnetic spins of the active nucleus in the fluoroelastomer and for receiving fluorine magnetic resonance data from the fluoroelastomer, and wherein the antenna is connected to the radio-frequency transceiver,
wherein the method comprises the steps of:
acquiring the fluorine magnetic resonance data using the magnetic resonance imaging system; and
calculating magnetic field strength in the imaging zone using the fluorine magnetic resonance data.

5. The method of claim 4 , wherein the active nucleus that includes 19 F is in any one of the following fluoroelastomers: a siloxane, a fluorinated polysiloxane (FVMQ), a fluorine containing polymer, methyl vinyl silicone, fluorine-containing polymers, a vinylidenefluoride elastomer, a tetrafluoroethylene elastomer, a perfluoromethylvinylether, a chlorotrifluoroethylene based elastomer, pentafluoropropylene, a hexafluoropropylene elastomer, a fluoroinorganic polymers, a fluorosilicone, and a fluorophosphazene.

6. The method of claim 4 , wherein the method further comprise the steps of:
acquiring image magnetic resonance data from a subject in the imaging zone using the magnetic resonance imaging system;
calculating corrected magnetic resonance data using the magnetic field strength and the image magnetic resonance data; and
reconstructing an image of the subject from the corrected magnetic resonance data.

7. A magnetic field probe for a magnetic resonance imaging system comprising:
a fluorine containing ionic liquid sample including a 19 F active nucleus containing ionic liquid, and a fluorine relaxation agent, wherein the fluorine relaxation agent is manganese trifluoromethanesulfonate; and
an antenna configured to manipulate magnetic spins of the fluorine containing ionic liquid sample and for receiving fluorine magnetic resonance data from the 19 F active nucleus.

8. A magnetic resonance imaging system comprising:
a magnet configured to provide a magnetic field in an imaging zone;
the magnetic field probe according to claim 7 located within the imaging zone;
a radio frequency transceiver configured to excite resonance in the 19 F active nucleus and receive resonance signals from the 19 F active nucleus; and
at least one computer processor configured to:
calculate change in a strength of the magnetic field in the imaging zone from the resonance signals from the 19 F active nucleus from the radio frequency transceiver and
reconstruct an image of a subject in the imaging zone corrected for the calculated changes in the strength of the magnetic field.

9. The magnetic field probe of claim 7 , wherein the fluorine containing ionic liquid is 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide or 1-Butyl-4-methylpyridinium tetrafluoroborate.

10. A method of measuring a magnetic field within a magnetic resonance imaging system,
the magnetic resonance imaging system including a magnet configured to provide an imaging zone, a radio-frequency transceiver, and a magnetic field probe located within the imaging zone, wherein the magnetic field probe contains a 19 F active ion including a 19 F active nucleus in an aqueous solution of a paramagnetic cat-ion salt, wherein the field probe further comprises an antenna for manipulating the magnetic spins of the 19 F active nucleus and for receiving fluorine magnetic resonance data from the 19 F active nucleus, and wherein the antenna is connected to the radio-frequency transceiver,
wherein the method comprises the steps of:
acquiring the fluorine magnetic resonance data using the magnetic resonance imaging system; and
calculating a magnetic field strength using the fluorine magnetic resonance data.

11. The method of claim 10 , wherein the method further comprise the steps of:
acquiring image magnetic resonance data from a subject in the imaging zone using the magnetic resonance imaging system;
calculating corrected magnetic resonance data using the magnetic field strength and the image magnetic resonance data; and
reconstructing an image of the subject from the corrected magnetic resonance data.

12. The method of claim 10 , wherein the 19 F active ion comprises an anion, wherein the anion is any one of the following: bis(trifluoromethylsulfonyl)imide, tetrafluoroborate, hexafluorophosphate, tetrafluoroaluminate, hexafluoroantimonate, hexafluoroarsenate, bis(trifluoromethane)sulfonimide, and tris(trifluoromethylsulfonyl)methide.

13. The method of claim 12 , further including a fluorine relaxation agent in the aqueous solution.

14. The method of claim 10 , wherein the 19 F active ion in the aqueous solution includes any one of the following: a trifluoroacetate salt, hydrofluoric acid, a flouride salt, a hexafluorosilicic salt, a hexafluorophosphate salt, with copper (II), manganese (I) or a trivalent ion of a lanthanide series as a counter ion.

15. A magnetic resonance imaging system, comprising:
a magnet configured to provide a magnetic field;
an imaging zone;
a magnetic field probe located within the imaging zone, the magnetic field probe containing a 19 F active ion in an aqueous solution of a paramagnetic cat-ion salt, the 19 F

Assignees

• Koninklijke Philips Nv

Inventors

• Fuderer Miha
• Pikkemaat Jeroen Alphons

Classifications

• G01R33/58

  Calibration of imaging systems, e.g. using test probes {, Phantoms; Calibration objects or fiducial markers such as active or passive RF coils surrounding an MR active material} · CPC title

• G01R33/56563

  caused by a distortion of the main magnetic field B0, e.g. temporal variation of the magnitude or spatial inhomogeneity of B0 (G01R33/56509, G01R33/56518, G01R33/56536 take precedence) · CPC title

• G01R33/443

  Assessment of an electric or a magnetic field, e.g. spatial mapping, determination of a B0 drift or dosimetry · CPC title

• G01R33/34046

  Volume type coils, e.g. bird-cage coils; Quadrature bird-cage coils; Circularly polarised coils · CPC title

• G01R33/24 Primary

  for measuring direction or magnitude of magnetic fields or magnetic flux · CPC title