Vascular Skills REQUIRED: Aorta, Carotid, Color Flow, Dialysis grafts, Doppler Studies, Duplex, Lower Extremity Arterial, Lower Extremity Venous, Peripheral Vascular Resistance, Renal Artery Duplex, Upper Extremity Arterial & Upper Extremity Venous. Travelers may start on Wednesday, Thursday, or Friday of the first week, and must be fully available with no other commitments to accommodate any schedule changes.