An apparatus for treating a treatment area in the vasculature using a catheter, such as one designed to deliver a payload (such as a therapeutic agent (e.g., a drug, such as paclitaxel, rapamycin, heparin and the like), a stent, a stent graft, or a combination thereof) or a working element (such as a cutter, focused force wire, or the like) to a specified location within the vasculature. The catheter may include at least one first radiopaque marking. A guidewire (26) for guiding the catheter to the treatment area includes an anchor (26a) for selectively anchoring the guidewire to the vasculature, and at least one second radiopaque marking (26b) for corresponding to the at least one first radiopaque marking of the catheter when positioned at the treatment area.
