Biopsy apparatus

1. A biopsy apparatus, comprising:

a disposable cutting element and a reusable handpiece;

wherein the disposable cutting element includes an outer cannula defining an outer lumen, a tissue-receiving opening proximate a distal end of the outer cannula communicating with the outer lumen, and an inner cannula slidably disposed within the outer lumen and defining an inner lumen from an open distal end to an open proximal end opposite the distal end, wherein the inner cannula includes a cutting edge at the open distal end operable to sever tissue projecting through the tissue-receiving opening, and a tissue aspiration path in the inner lumen from the open distal end of the inner cannula to the open proximal end of the inner cannula; and

wherein the reusable handpiece includes a first MRI compatible device detachably coupled to said inner cannula to rotate the inner cannula within the outer cannula, and a second MRI compatible device detachably coupled to the inner cannula to translate the inner cannula within the outer cannula while the inner cannula rotates, wherein the second MRI compatible device includes a hydraulic cylinder and a piston slidably disposed within said cylinder.

2. The biopsy apparatus of claim 1 , further including a return spring disposed within the cylinder and biased against the piston to move the piston, and the inner cannula in a predetermined direction away from the distal end of the outer cannula.

3. The biopsy apparatus of claim 1 , further comprising a vacuum source in fluid communication with the open proximal end of the inner cannula such that when the vacuum source is activated, severed tissues samples are aspirated through the open proximal end of the inner cannula.

4. The biopsy apparatus of claim 3 , further including a tissue collection chamber removably mounted to the handpiece and interposed between the vacuum source and an end of the inner cannula to receive severed tissue drawn into the chamber by the vacuum.

5. The biopsy apparatus of claim 4 , wherein the tissue collection chamber includes a filter that permits fluid to pass while retaining the severed tissue within the chamber.

6. The biopsy apparatus of claim 1 , wherein the disposable cutting element snaps into the reusable handpiece.

7. The biopsy apparatus of claim 1 , wherein the cutting element is slidingly engaged with the reusable handpiece.

8. The biopsy apparatus of claim 1 , wherein the inner and outer cannulae are constructed of inconel or titanium.

9. The biopsy apparatus of claim 1 , wherein the cutting edge of the cuffing element is an inwardly beveled surface.

10. The biopsy apparatus of claim 1 further including a trocar tip.

11. The biopsy apparatus of claim 10 , wherein the trocar tip has an engagement hub configured to fit tightly within the distal end of the outer cannula.

12. The biopsy apparatus of claim 11 , wherein the hub includes an irrigation fitting having an irrigation lumen.

13. The biopsy apparatus of claim 1 , further including a cutting board disposed at the distal end of the outer cannula.

14. The biopsy apparatus of claim 13 , wherein the cutting board is affixed to an engagement hub that is affixed to a trocar tip.

15. The biopsy apparatus of claim 1 , further comprising a drive gear disposed about a portion of the length of the inner cannula and having a plurality of longitudinally extending gear teeth.

16. The biopsy apparatus of claim 15 , wherein the first MRI compatible device comprises an actuating gear detachably engaged to the drive gear such that when the actuating gear engages the drive gear and rotates, the drive gear rotates, thereby causing the inner cannula to rotate within the outer cannula.

17. The biopsy apparatus of claim 15 , wherein the second MRI compatible device comprises a piston and a push rod, wherein the push rod has a first end engaged to the piston and a second end detachably engaged to the drive gear.

18. The biopsy apparatus of claim 17 , wherein the drive gear comprises an annular recess and the second end of the push rod detachably engages the annular recess.

19. The biopsy apparatus of claim 1 , further comprising a drive gear having first and second ends and a plurality of longitudinal teeth disposed about a portion of the length of the inner cannula, wherein the first MRI compatible device is a hydraulic rotary motor that is detachably coupled to the drive gear and the second MRI compatible device is a hydraulic reciprocating motor that is detachably coupled to the drive gear adjacent the first end of the drive gear, and the hydraulic reciprocating motor comprises a hydraulic cylinder and a piston slidably disposed within the cylinder such that translation of the piston within the hydraulic cylinder causes the inner cannula to translate within the outer cannula as the inner cannula rotates.

20. A biopsy apparatus, comprising:

a disposable cutting element detachably connected to a reusable handpiece;

wherein the disposable cutting element includes an outer cannula defining an outer lumen, a tissue-receiving opening proximate a distal end of the outer cannula communicating with the outer lumen, an inner cannula slidably disposed within the outer lumen and defining an inner lumen from an open distal end to an open proximal end opposite the distal end, and a drive gear disposed about a portion of a length of the inner cannula and having a plurality of longitudinally extending teeth, wherein the inner cannula includes a cutting edge at the open distal end operable to sever tissue projecting through the tissue-receiving opening, and a tissue aspiration path in the inner lumen that passes through the drive gear; and

wherein the reusable handpiece includes a hydraulic rotary motor detachably coupled to said inner cannula by said drive gear to rotate the inner cannula within the outer cannula, and a hydraulic reciprocating motor detachably coupled to the inner cannula to translate the inner cannula within the outer cannula while the inner cannula rotates.

21. The biopsy apparatus of claim 20 , wherein the disposable cutting element snaps into the reusable handpiece.

22. The biopsy apparatus of claim 20 , wherein the cutting element is slidingly engaged with the reusable handpiece.

23. The biopsy apparatus of claim 20 , wherein the inner and outer cannulae are constructed of inconel or titanium.

24. The biopsy apparatus of claim 20 , wherein the hydraulic rotary motor and the hydraulic reciprocating motor are constructed of a material that is compatible with MRI.

25. The biopsy apparatus of claim 20 further including a vacuum source fluidly connected to the inner cannula for generating a vacuum in the lumen of the inner cannula to draw severed tissue through the open distal end of the inner cannula and the open proximal end of the inner cannula, and a tissue collection chamber positioned between the vacuum source and an end of the inner cannula to receive severed tissue drawn into the chamber by the vacuum.

26. A biopsy apparatus, comprising:

a disposable cutting element and a reusable handpiece;

wherein the disposable cutting element includes an outer cannula defining an outer lumen, a tissue-receiving opening proximate a distal end of the outer cannula communicating with the outer lumen, and an inner cannula slidably disposed within the outer lumen and defining an inner lumen from an open distal end of the inner cannula to an open proximal end of the inner cannula opposite the distal end of the inner cannula, the inner cannula includes a cutting edge at the open distal end that is operable to sever tissue projecting through the tissue-receiving opening, the disposable cutting element further includes a drive gear having first and second ends and a plurality of longitudinal teeth disposed about a portion of a length of the inner cannula, a tissue aspiration path in the inner lumen from the open distal end of the inner cannula to the open proximal end of the inner cannula, and a tissue collection chamber with a filter, such that the open proximal end of the inner cannula is disposed in the tissue collection chamber;

wherein the reusable handpiece includes an MRI compatible hydraulic rotary motor detachably coupled to the drive gear to rotate the inner cannula within the outer cannula, and an MRI compatible hydraulic reciprocating motor, and the hydraulic reciprocating motor comprises a hydraulic cylinder, a piston slidably disposed in the hydraulic cylinder, and a push rod having a first end connected to the piston and a second end detachably coupled to the drive gear adjacent the first end of the drive gear to translate the inner cannula within the outer cannula while the inner cannula rotates.