Method and apparatus for performing neuroimaging

• US 6,873,156 B2
• Filed: 02/13/2003
• Issued: 03/29/2005
• Est. Priority Date: 05/06/1998
• Status: Expired due to Fees

• Current Assignee: Ekam Imaging Inc.
• Original Assignee: Insight Neuroimaging Systems LLC
• Inventors: King, Jean A, Bogdanov, Gene, Ludwig, Reinhold, Ferris, Craig F., Allard, Arthur C.
• Primary Examiner(s): Shrivastav, Brij B.
• Application Number:
  US10/365,952
• Publication Number:
  US 20030164703A1
• Time in Patent Office: 775 Days
• Field of Search: 324/318, 324/309, 324/307, 324/319, 324/322, 660/410, 128/653.1
• US Class Current: 324/318
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61B 5/702 Posture restraints
• CPC Class Codes: G01R 33/34007 Manufacture of RF coils, e.g. using printed circuit board technology; additional hardware for providing mechanical support to the RF coil assembly or to part thereof, e.g. a support for moving the coil assembly relative to the remainder of the MR system
• CPC Class Codes: G01R 33/34046 Volume type coils, e.g. bird-cage coils; Quadrature bird-cage coils; Circularly polarised coils
• CPC Class Codes: G01R 33/341 comprising surface coils
• CPC Class Codes: G01R 33/3453 Transverse electromagnetic [TEM] coils

Abstract

The present invention relates to systems and methods of performing magnetic resonance imaging (MRI) in awake animals. The invention utilizes head and body restrainers to position an awake animal relative to a radio frequency dual coil system operating in a high field magnetic resonance imaging system to provide images of high resolution without motion artifact.

Claims

1. A dual coil system for magnetic resonance imaging, the system comprising:

a surface coil;

a volume coil having a cylindrical non-magnetic core module having an outer surface and a longitudinal axis, a cylindrical bore extending through the core module along the longitudinal axis and defining an inner surface;

a plurality of conductive strip lines, the strip lines extending parallel to the longitudinal axis on the inner surface of the core module;

a pair of circuit boards carried at the ends of the core module; and

a plurality of resonating elements, each of the resonating elements including one of the strip lines and at lease one tuneable capacitor, wherein the volume coil includes features formed therein that permit the volume coil to be slidably moved along the longitudinal axis along guide members associated with a frame.

2. The dual system of claim 1 further comprising a transceiver unit having a RF transmitter and a RF receiver, the transceiver unit connected to the surface coil and the volume coil.

3. A dual coil system for magnetic resonance imaging, the system comprising:

a surface coil;

a volume coil having a cylindrical non-magnetic core module having an outer surface and a longitudinal axis, a cylindrical bore extending through the core module along the longitudinal axis and defining an inner surface;

a plurality of conductive strip lines, the strip lines extending parallel to the longitudinal axis on the inner surface of the core module;

a pair of circuit boards carried at the ends of the core module; and

a plurality of resonating elements, each of the resonating elements including one of the strip lines and at lease one tuneable capacitor; and

a transceiver unit having a RF transmitter and a RF receiver, the transceiver unit connected to the surface coil and the volume coil, wherein the volume coil further comprises a plurality of shielding strips extending parallel to the longitudinal axis on the outer surface of the core module and wherein the adjacent shielding strips are connected by at least one capacitor attaching adjacent shielding strips at alternative ends of the shielding strips.

4. The dual coil system of claim 3 wherein the core module of the volume coil is formed of a dielectric material and the strip lines of the volume coil are electroplated on the core module.

5. The dual coil system of claim 4 further comprising a matching circuit for adjusting the impedance of the resonating elements to that of the RF source and a filter for separating the high frequency RF signal from interfering with the DC tuning/detuning signal.

6. The dual coil system of claim 4 wherein both the surface coil and volume coil have a detuning circuit for detuning the resonating element and a RF decoupling circuit for reducing interference between a DC detuning signal and a RF signal.

7. The dual coil system of claim 4 wherein the surface coil comprises a single loop or a dome shaped coil having a curvilinear surface.

8. A surface coil comprising;

a curvilinear support surface having a concave inner surface and a convex outer surface;

a circuit board assembly;

at least a pair of conductive strips carried on the concave inner surface;

at least one capacitor connecting the conductive strips; and

a tuneable variable capacitor, wherein there are at least four conductive strips carried on the concave inner surface and further comprising a resonating element including one of the conductive strips on the concave inner surface, and a shielding strip on the convex outer surface.

9. The surface coil of claim 8 further comprising:

a detuning circuit for detuning the resonating elements;

a RF decoupling circuit for reducing interference between a C detuning signal and an RF signal; and

a matching circuit for adjusting the impedance of the resonating elements to that of a RF source.

10. A dual RF resonator system that is adapted to be variably positioned over an anatomical region of interest of a biological entity comprising:

a volume resonator having a plurality of conductive strip lines and being configured for mounting on guide members so as to enable variable positioning and repositioning of the volume resonator along a longitudinal direction by slidably moving the volume resonator along the guide members; and

a surface coil having a plurality of conductive strip lines and being configured to be integrated into a member so as to enable positioning of the surface coil along a vertical direction.

11. The resonator of claim 10, wherein the volume coil has a cylindrical non-magnetic core module having an outer surface and a longitudinal axis, a cylindrical bore extending through the core module along the longitudinal axis and defining on inner surface;

the plurality of conductive strip lines extending parallel to the longitudinal axis on the inner surface of the core module;

a pair of circuit boards carried at the ends of the core module; and

a plurality of resonating elements, each of the resonating elements including one of the strip lines and at lease one tuneable capacitor.

12. The RF resonator of claim 10, further comprising:

a transceiver unit having a RF transmitter and a RF receiver, the transceiver unit connected to the surface coil and the volume coil.

13. The RF resonator of claim 12, wherein the volume coil further comprises a plurality of shielding strips extending parallel to the longitudinal axis on the outer surface of the core module and wherein the adjacent shielding strips are connected by at least one capacitor attaching adjacent shielding strips at alternative ends of the shielding strips.

14. The RF resonator of claim 10, wherein the surface coil comprises a single loop or a dome shaped coil having a curvilinear surface.

15. The RF resonator of claim 13, further comprising:

a matching circuit for adjusting the impedance of the resonating elements to that of the RF source and a filter for separating the high frequency RF signal from interfering with the DC tuning/detuning signal.

16. A dual RF resonator system that is associated with a frame and is adapted to be flexibly positioned over an anatomical region of a subject comprising:

a volume resonator that includes a plurality of arranged conductive strip lines, the volume resonator having a plurality of longitudinal features formed therein for mating with complementary guide members associated with the frame so as to enable the volume resonator to be slidably moved along the guide members in a longitudinal direction relative to the frame so as to permit variable positioning and repositioning of the volume resonator relative to the guide members; and

a surface coil that includes a plurality of arranged conductive strip lines and is configured to be integrated into a member so as to enable positioning of the surface coil along a vertical direction relative to the frame.

17. The RF resonator of claim 16, wherein the volume coil has a cylindrical non-magnetic core module having an outer surface and a longitudinal axis, a cylindrical bore extending through the core module along the longitudinal axis and defining an inner surface;

the plurality of conductive strip lines extending parallel to the longitudinal axis on the inner surface of the core module;

a pair of circuit boards carried at the ends of the core module; and

a plurality of resonating elements, each of the resonating elements including one of the strip lines and at lease one tuneable capacitor.

18. The RF resonator of claim 16, further comprising:

a transceiver unit having a RF transmitter and a RF receiver, the transceiver unit connected to the surface coil and the volume coil.

19. The RF resonator of claim 18, wherein in volume coil further comprises a plurality of shielding strips extending parallel to the longitudinal axis on the outer surface of the core module and wherein the adjacent shielding strips are connected by at least one capacitor attaching adjacent shielding strips at alternative ends of the shielding strips.