Pw And Cw Doppler Controls - GE Vivid i User Manual

PW and CW Doppler controls

PW and CW Doppler assignable controls
Horizontal sweep
Adjusts the horizontal refresh rate of the Doppler area of the
display. Horizontal sweep is available in live and cine replay.
Baseline
Enables the Doppler baseline to be shifted up and down. The
default Doppler baseline is set at the center of the vertical
aspect of the Doppler display, dividing evenly the flow toward
and away from the probe. By adjusting the baseline a larger
portion of the analysis is assigned to the flow direction present.
Baseline is available in live and cine replay.
Velocity range
Maximum velocity
depends on sample
Enables the vertical scale of the Doppler spectrum and the
volume size, sample
maximal detectable velocity to be modified. Velocity range
volume position and
directly controls the pulse repetition frequency, which is
frequency settings.
responsible for the setting of the Nyquist limit (the ability to
detect maximum velocity without aliasing).
Scale
Enables the low velocity portions of the spectrum to be filtered,
since the Doppler spectrum and audio may contain strong
wall-motion signals. The amount of Low Velocity Reject. is
indicated by the green vertical bar at the right end of the
baseline.
Invert
If the Doppler mode
is combined with
Enables the Doppler spectrum to be flipped 180 degrees, so
Color mode, the
that negative velocities are displayed above the baseline and
color map will be
positive velocities below the baseline. Invert is available in live
also inverted.
and cine replay.
LPRF (PW mode)
Sets the pulse repetition frequency for the PW Doppler
acquisition of flow data. Enables toggling between high and low
Pulse Repetition Frequency (PRF). When the Doppler PRF is
raised beyond a certain limit, more than one Doppler gate is
displayed on the screen.
Vivid i User's Manual
2378958-100 Rev. 02
Scanning Modes
95