Catheters and methods for supporting a guidewire or delivering a radiopaque,diagnosticor therapeutic agent through a vessel stenosis or other tortuous anatomy aredisclosed. Acatheter can comprise an elongate shaft body and a tip member disposed at adistal end of theshaft body. The shaft body can extend from a proximal end to the distal endand can define aninner lumen. The shaft body can include a liner, a braid member surroundingthe liner, amulti-layer coil surrounding the braid member, and a polymer cover surroundingthe multi-layer coil.An outer surface portion of the polymer cover can include one or more helicalthreads, which canbe enveloped in an outer wrapper. The tip member can be made from a metal or apolymer.Polymer tip members can include a hard or semi-hard distal tip.
