Tunable MRI enhancing device

• US 20040030242A1
• Filed: 08/12/2002
• Published: 02/12/2004
• Est. Priority Date: 08/12/2002
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Weber, Jan
• Granted Patent: US 7,725,160 B2
• Time in Patent Office: Days
• US Class Current: 600/423
• CPC Class Codes: G01R 33/285 Invasive instruments, e.g. catheters or biopsy needles, specially adapted for tracking, guiding or visualization by NMR
• CPC Class Codes: G01R 33/3628 Tuning/matching of the transmit/receive coil

Abstract

The present invention is directed to an MIR enhancing device deployable in a body. In one embodiment, the MRI enhancing device is formed of a wire loop and a capacitor that is at least partially formed by the wire used in forming the wire loop.

Claims

1. A device for use in a body during a magnetic resonance imaging (MRI) procedure, comprising:

an elongate member having a proximal end and a distal region;

a wire forming a coil coupled to the distal region of the elongate member and formed of a coil material such that the coil forms an electrical inductor; and

a capacitor comprising at least a portion of the wire.

2. The device of claim 1 wherein the wire is movable between a collapsed insertion position and an expanded deployed position.

3. The device of claim 2 wherein the wire is arranged such that the inductor and capacitor are in series with one another when the wire is in the deployed position.

4. The device of claim 3 wherein the inductor and capacitor form an LC circuit tuned to a Larmor frequency of an MRI system used for the MRI procedure.

5. The device of claim 3 wherein the wire has a first end and a second end, the first and second ends forming plates of the capacitor.

6. The device of claim 5 wherein the first and second ends have facing sides, that face one another, the facing sides being flattened to form the plates of the capacitor.

7. The device of claim 5 and further comprising:

a dielectric material between the plates of the capacitor.

8. The device of claim 5 wherein a resonant frequency of the capacitor and inductor is selectively variable when the wire is in the body.

9. The device of claim 8 wherein the capacitance of the capacitor is variable when the wire is in the body.

10. The device of claim 8 and further comprising:

a dielectric material displaceably movable between the plates of the capacitor when the wire is in the body to vary the capacitance of the capacitor.

11. The device of claim 5 wherein the elongate member comprises:

a core wire attached to one of the first and second ends of the wire.

12. The device of claim 11 and further comprising:

a filter basket coupled to the wire.

13. The device of claim 12 wherein the wire is coupled to the filter basket to define a proximally facing mouth of the filter basket.

14. The device of claim 5 wherein the elongate member comprises a catheter coupled to one of the first and second ends of the wire.

15. The device of claim 14 and further comprising:

a balloon coupled to the wire and to the catheter.

16. The device of claim 15 wherein the wire is embedded in a wall of the balloon.

17. The device of claim 15 wherein the wire includes a pair of leads and wherein the plates of the capacitor are formed by the leads.

18. The device of claim 1 wherein the wire forms a plurality of loops.

19. The device of claim 1 wherein the wire comprises:

a bundle of wires.

20. A device for use within a body during a magnetic resonance imaging (MRI) procedure, comprising:

an elongate member;

a coil coupled to a distal portion of the elongate member; and

a capacitor coupled to the coil such that the capacitor and coil form an active circuit arranged so a resonant frequency of the active circuit is selectively tunable when the active circuit is in the body.

21. The device of claim 20 wherein the capacitor includes plates and further comprising:

a movable dielectric member, selectively movable between the plates of the capacitor to vary a capacitance of the capacitor.

22. The device of claim 21 wherein the coil is formed of a wire having first and second ends and wherein the capacitor is at least partially formed from at least one of the first and second ends.

23. The device of claim 22 wherein the first and second ends of the wire are flattened to form the plates of the capacitor.

24. The device of claim 20 and further comprising:

a collapsible filter coupled to the coil.

25. The device of claim 20 wherein the wire forms a proximally facing mouth of the collapsible filter when the collapsible filter is deployed.

26. The device of claim 20 wherein the coil comprises a multi-turn coil.

27. The device of claim 20 and further comprising:

a balloon coupled to the coil.

28. The device of claim 20 wherein the coil comprises a bundle of wires.

29. An intravascular filter, comprising:

an elongate member;

a filter portion coupled to the elongate member;

a coil disposed on the filter portion; and

a capacitor coupled to the coil to form an active circuit when the intravascular filter is deployed in a body.

30. The intravascular filter of claim 29 wherein the active circuit is selectively tunable when deployed in the body.

31. The intravascular filter of claim 29 wherein at least a portion of the coil forms at least a portion of the capacitor.

32. The intravascular filter of claim 29 and further comprising:

a movable dielectric material, selectively movable between plates of the capacitor to selectively vary a capacitance of the capacitor.

33. An intravascular balloon catheter, comprising:

an elongate member;

a balloon coupled to the elongate member;

a coil disposed on the balloon; and

a capacitor coupled to the coil to form an active circuit when the balloon catheter is deployed in a body.

34. The balloon catheter of claim 33 wherein the active circuit is selectively tunable when deployed in the body.

35. The balloon catheter of claim 33 wherein at least a portion of the coil forms at least a portion of the capacitor.

36. The balloon catheter of claim 33 and further comprising:

a movable dielectric material, selectively movable between plates of the capacitor to selectively vary a capacitance of the capacitor.

37. The balloon catheter of claim 36 wherein the movable dielectric material includes an elongate pusher member having a proximal end.

38. The balloon catheter of claim 37 wherein the proximal end of the elongate pusher member includes indicia indicative of an extent to which the balloon is inflated.