For treating a treatment area in the vasculature, this disclosure relates to a first, pre-dilatation catheter having a first shaft including a first distal portion adapted for positioning at the treatment area and a first proximal portion including a first marking at a first location. A second, dilatation catheter includes a second shaft including a second distal portion adapted for positioning at the treatment area and a second proximal portion including a second marking at a second location substantially matching a first location of the first marking. Related methods are disclosed.