Intravascular devices

1. An implantable medical device, comprising:

an elongate member made from a material, the material comprising an alloy that includes Platinum (Pt), Tungsten (W), and Zirconium (Zr);

wherein a percentage of the Tungsten (W) in the alloy is equal to or greater than 10% by weight;

wherein a percentage of the Platinum (Pt) and Tungsten (W) in the alloy is at least 95% by weight, and wherein a percentage of the Zirconium (Zr) in the alloy is 5% or less by weight.

2. The implantable medical device of claim 1 , wherein the elongate member has a cross-sectional dimension that is less than 0.002 inch.

3. The implantable medical device of claim 2 , wherein the cross-sectional dimension of the elongate member is anywhere from 0.0001 inch to 0.0008 inch.

4. The implantable medical device of claim 2 , wherein the cross-sectional dimension of the elongate member is anywhere from 0.0003 inch to 0.00075 inch.

5. The implantable medical device of claim 1 , wherein the percentage of Tungsten (W) in the alloy is less than 25% by weight.

6. The implantable medical device of claim 1 , wherein the elongate member has a greater ultimate tensile strength, a greater Young's modulus, and a lesser magnetic susceptibility, than those in identically dimensioned alternative elongate member composed of an alternative platinum-tungsten alloy having a percentage of tungsten that is 8% by weight.

7. The implantable medical device of claim 1 , wherein the material has a Young' modulus of 30 Msi or higher.

8. The implantable medical device of claim 1 , wherein the material has an ultimate tensile strength (UTS) that is 350 ksi or higher.

9. The implantable medical device of claim 1 , wherein the elongate member comprises a wire.

10. The implantable medical device of claim 9 , further comprising additional wires, wherein the wire and the additional wires are woven into a braid structure.

11. The implantable medical device of claim 10 , further comprising a first coil segment at a first end of the braid structure.

12. The implantable medical device of claim 10 , wherein the braid structure has a wire count that is anywhere from 8 to 96.

13. The implantable medical device of claim 9 , wherein the wire has a helical coil shape.

14. The implantable medical device of claim 1 ,

wherein the implantable medical device has a longitudinal axis and a length measured in a direction of the longitudinal axis that is at least 1.2 inch,

wherein the implantable medical device is insertable lengthwise into an inner lumen of a tube having an inner lumen diameter not greater than 0.02 inch, and

wherein the implantable medical device has a column strength sufficient to allow the implantable medical device to be pushed through the lumen without undergoing buckling, kinking, or plastic deformation.

15. The implantable medical device of claim 1 , wherein the alloy comprising the Platinum (Pt), the Tungsten (W), and the Zirconium (Zr) is not a Mo—Re alloy.