(MVO) Maximum venous outflow is the maximum rate of venous evacuation occurring in an extremity following rapid cuff deflation after venous occlusion.

The Doppler velocity signal refers to a signal whose voltage is proportional to the Doppler frequency shift, obtained by a frequency-to-voltage conversion of the Doppler signal.

See also Autocorrelation, Temporal Mean Velocity, Doppler Effect, Doppler Ultrasound and Maximum Venous Outflow.

Peripheral veins are easily tested using a 5 to 10 MHz transducer. The venous walls are smooth, thin, and compressible. Venous ultrasound imaging requires the compression of the veins in the transverse view. If compression is performed in the longitudinal view, the vein may roll away from the transducer possibly creating a false-negative examination.
The lumen of the normal vein is echo free. Increasing the gain will display low level echoes representing venous blood moving towards the heart. When performing Doppler spectral analysis or color Doppler the gate should be placed in the center of the vessel. In case of a non-obstructing or recanalized thrombosis, the Doppler gate should be placed within the remaining vessel lumen for flow detection.

See also Maximum Venous Outflow and Zero Offset.