Duplex examination.
BACKGROUND: Accurate venous diagnosis remains a challenge for the phlebologist and vascular laboratory. In recent years duplex ultrasound has become the preferred method of diagnosis for deep venous thrombosis and deep and superficial venous insufficiency. OBJECTIVE: To describe the physical principles, typical protocol, and indications for venous duplex examination. CONCLUSION: Duplex examination offers a precise, noninvasive technique to make anatomic and functional venous diagnoses.