A catheter assembly and related methods include first and second catheter branches that are configured to travel over separate guidewires to a vessel bifurcation treatment site within a patient. The catheter branches can each include a plurality of markers. The position of markers on one catheter branch relative to the position of markers on the other catheter branch provide a visual indication of relative twist between the catheter branches, can help distinguish one catheter branch from the other, and help with visual alignment of the catheter branches relative to the vessel bifurcation.