Fig. 2

Representative screen shot from pulsed Doppler ultrasound for measurement of the peak venous velocity and diameter of the popliteal vein (Pop. V). Both were measured in the short-axis view. In this picture, the venous velocity was measured at the center of double line (denoted as equal sign) continuously and then the pulse wave was figured. The peak velocity was measured at the top of the pulse wave (denoted as plus sign)