Biopsy and Sampling Needle Antennas for Magnetic Resonance Imaging-Guided Biopsies

• US 20070238978A1
• Filed: 06/12/2007
• Published: 10/11/2007
• Est. Priority Date: 04/25/1996
• Status: Active Grant

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Kumar, Ananda, Atalar, Ergin, Ocali, Ogan
• Granted Patent: US 7,778,682 B2
• Time in Patent Office: Days
• US Class Current: 600/411
• CPC Class Codes: A61B 10/0275 with sample notch, e.g. on the side of inner stylet
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61B 2090/3958 emitting a signal
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: G01R 33/287 involving active visualization of interventional instruments, e.g. using active tracking RF coils or coils for intentionally creating magnetic field inhomogeneities
• CPC Class Codes: G01R 33/34084 implantable coils or coils being geometrically adaptable to the sample, e.g. flexible coils or coils comprising mutually movable parts
• CPC Class Codes: G01R 33/341 comprising surface coils
• CPC Class Codes: G01R 33/3628 Tuning/matching of the transmit/receive coil
• CPC Class Codes: G01R 33/3657 Decoupling of multiple RF coils wherein the multiple RF coils do not have the same function in MR, e.g. decoupling of a transmission coil from a receive coil

Abstract

Herein is disclosed a magnetic resonance imaging antenna, including an inner conductor, an outer shield slideably displaceable with respect to the inner conductor, and an insulator electrically insulating the inner conductor from the outer shield. Herein is disclosed a biopsy needle antenna, including a magnetic resonance imaging antenna, having an outer shield, and an inner conductor electrically insulated from the outer shield by a dielectric; and a biopsy needle electrically connected to the inner conductor and electrically insulated from the outer shield by the dielectric. Herein is disclosed a method of obtaining a sample with magnetic resonance imaging guidance, including providing a sampling needle magnetic resonance imaging antenna, advancing the antenna to a structure from which the sample is to be taken, detecting magnetic resonance data by the antenna, and coupling the sample to the antenna.

Claims

1. A biopsy needle antenna, comprising:

a cannula being formed at least in part of a conductive material;

an obturator being formed at least in part of a conductive material, the obturator being slideably displaceable relative to the cannula;

an insulator electrically insulating the cannula from the obturator; and

a connector that can couple the cannula and the obturator to a magnetic resonance interface circuit.

2. A biopsy needle according to claim 1, wherein the obturator defines an inner conductor of a coaxial cable and the cannula defines an outer conductor thereof, and wherein the sliding displacement causes the cannula to cooperate with the obturator to cut and capture a biopsy sample.

3. A biopsy needle according to claim 1, wherein the insulator resides snugly against the outer wall of the obturator.

4. A biopsy needle according to claim 1, wherein the cannula, obturator and insulator cooperate to define an MRI antenna, and wherein the insulator is configured as an electrical insulator and a dielectric for the antenna.

5. A biopsy needle according to claim 1, wherein the obturator has a diameter in the range of 0.03 inches to 0.15 inches.

6. A biopsy needle according to claim 1, wherein the obturator has a sharp distal end portion that merges axially upstream into a side slit formed into an outer wall of the obturator, the side slit defining an entry into a biopsy sample chamber in the obturator.

7. A biopsy needle according to claim 6, wherein a distal end of the cannula is configured to slidably advance toward the cannula to obtain a biopsy sample of local tissue and hold the biopsy sample in the biopsy sample chamber.

8. A biopsy needle according to claim 7, further comprising a plunger that directs the cannula or the obturator to cut a biopsy sample of local tissue.

9. A biopsy needle according to claim 1, wherein the obturator has a tissue penetrating sharp end that resides outside the cannula during in vivo MRI guided placement.

10. A biopsy collection and MRI antenna device, comprising:

a cannula being formed at least in part of a conductive material;

an obturator being formed at least in part of a conductive material, wherein at least one of the obturator and cannula are slideably displaceable relative to the other;

an insulator electrically insulating the cannula from the obturator; and

a connector that can couple the cannula and the obturator to a magnetic resonance interface circuit, wherein the obturator, insulator and cannula cooperate to define an MRI antenna for an MRI guided biopsy procedure.

11. A device according to claim 10, wherein the obturator defines an inner conductor of a coaxial cable and the cannula defines an outer conductor thereof, and wherein the sliding movement causes the cannula to cooperate with the obturator to cut and capture a biopsy sample.

12. A device according to claim 10, wherein the insulator resides snugly against the outer wall of the obturator.

13. A biopsy needle according to claim 10, wherein the cannula, obturator and insulator cooperate to define an MRI antenna, and wherein the insulator is configured as an electrical insulator and a dielectric for the antenna.

14. A biopsy needle according to claim 10, wherein the obturator has a diameter in the range of 0.03 inches to 0.15 inches.

15. A biopsy needle according to claim 10, wherein the obturator has a sharp, tissue-pentetratable distal end portion that merges axially upstream into a side slit formed into an outer wall of the obturator, the side slit defining an entry into a biopsy sample chamber in the obturator.

16. A biopsy needle according to claim 15, wherein a distal end of the cannula is configured to slidably advance toward the cannula to obtain a biopsy sample of local tissue and hold the biopsy sample in the biopsy sample chamber.

17. A biopsy needle according to claim 10, further comprising a plunger that directs the cannula or the obturator to cut a biopsy sample of local tissue

18. A magnetic resonance imaging antenna, comprising:

an inner conductor;

a conductive outer shield slideably displaceable with respect to the inner conductor; and

an insulator electrically insulating the inner conductor from the outer shield.

19. A magnetic resonance imaging antenna according to claim 18, wherein the inner conductor is an obturator with a sharp end portion and a biopsy sample hollow chamber, wherein the outer shield is a cannula that resides over at least a portion of the obturator, and wherein, in operation, at least one of the obturator and cannula slidably translates relative to the other to cut and capture a local biopsy sample using the antenna to perform an MRI guided biopsy procedure.