Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Color Doppler ultrasound image during knee extension with passive dorsiflexion of the ankle showing significantly reduced caliber of the popliteal vein (PV) and cessation of venous flow (arrow). Arterial flow remained unaffected. PA, Popliteal artery.
