Apparatus, systems, and methods for localizing markers or tissue structures within a body

1. A method of implanting a marker within a patient's body, the method comprising:

constraining a marker in a straightened shape prior to implanting the marker in the body, wherein the marker comprises:

an elongate core member having first and second free ends, and

a plurality of beads coupled to the core member with adjacent beads nested against one another, the beads comprising a plurality of flat surfaces and abrupt edges to enhance reflection of micro-impulse radar signals to facilitate identification of the marker,

wherein each bead of the plurality of beads has a passage there through, and wherein the elongate core member is received through the passage of each bead; and

implanting the marker, wherein the elongate core member is biased to assume a non-linear shape when implanted.

2. The method of claim 1 , further comprising, loading the marker into a delivery device, wherein the elongate core member is biased to the non-linear shape yet is resiliently flexible to allow the elongate core member to be straightened to facilitate loading the marker into the delivery device.

3. The method of claim 1 , wherein the core member is biased to a helical shape.

4. The method of claim 3 , wherein the core member is biased to a tapered helical shape.

5. The method of claim 1 , further comprising placing a probe adjacent the target tissue region, the probe transmitting electromagnetic signals towards the target tissue region, receiving electromagnetic signals reflected from the target, and displaying spatial information provide a spatial relationship between the target and the probe.

6. The method of claim 1 , further comprising releasing a tether from the marker.

7. A method for localizing a target tissue region within a patient's body, comprising:

introducing a target into the target tissue region such that when the target is implanted the target is independent of a delivery device used to introduce the target, wherein the target comprises:

an elongate core member having first and second free ends, and

a plurality of beads coupled to the core member with adjacent beads nested against one another, the beads comprising a plurality of flat surfaces and abrupt edges to enhance reflection of micro-impulse radar signals to facilitate identification of the target,

wherein each bead of the plurality of beads has a passage there through, and wherein the elongate core member is received through the passage of each bead;

placing a probe adjacent the target tissue region; and

activating the probe, whereupon the probe transmits electromagnetic signals towards the target tissue region, receives electromagnetic signals reflected from the target, and displays spatial information providing a spatial relationship between the target and the probe.

8. The method of claim 7 , wherein the spatial information comprises a distance between the target and the probe.

9. The method of claim 7 , wherein the spatial information comprises a relative angular orientation between the target and the probe.

10. The method of any one of claim 7 , wherein introducing a target comprises advancing a localization wire through the tissue into the target tissue region, the localization wire carrying the target.

11. The method of any one of claim 7 , wherein introducing a target comprises implanting a plurality of targets within the target tissue region.

12. The method of claim 7 , further comprising introducing a second target into the target tissue region spaced apart from a first targets to further define a desired margin.

13. The method of claim 12 , further comprising introducing a plurality of additional targets into the target tissue region to at least partially surround a lesion, the additional targets spaced apart from the lesion to further define the desired margin.

14. A method for localizing a target tissue region within a patient's body, comprising:

introducing a plurality of targets in a three dimensional array within or around the target tissue region, wherein each of the targets comprise:

an elongate core member having first and second free ends, and

a plurality of beads coupled to the core member with adjacent beads nested against one another, the beads comprising a plurality of flat surfaces and abrupt edges to enhance reflection of micro-impulse radar signals to facilitate identification of the target,

wherein each bead of the plurality of beads has a passage there through, and wherein the elongate core member is received through the passage of each bead;

placing a probe adjacent the target tissue region; and

activating the probe, whereupon the probe transmits electromagnetic signals towards the target tissue region, receives electromagnetic signals reflected from the targets, and displays spatial information providing a spatial relationship between the targets and the probe.

15. The method of claim 14 , wherein each of the targets includes one or more features to distinguish the targets from each other, and wherein the probe displays spatial information providing a spatial relationship between specific targets and the probe.

16. The method of claim 14 , further comprising loading the targets into a delivery device, wherein targets comprise an elongate core member that is biased to the non-linear shape yet is resiliently flexible to allow the elongate core member to be straightened to facilitate loading the targets into the delivery device.

17. The method of claim 14 , wherein the elongate core member is biased to a helical shape.

18. The method of claim 14 , further comprising releasing a tether from the targets.