User's Manual

Acclarix LX9 Series Diagnostic Ultrasound System User Manual Imaging
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5.3.3. HPRF
Conventional PW Doppler scales are limited by the Nyquist limit. High Pulse Repetition Frequency
(HPRF) allows the system to exceed the Nyquist limit by having multiple Doppler pulses in the body at
the same time. In HPRF imaging, multiple Doppler gates are displayed since the multiple Doppler
pulses could be giving information from different depths. HPRF is automatically invoked when needed
to maintain the requested depth and scale. For example, if the system is at a high scale and you move
the cursor deeper, the system may automatically invoke HPRF. This can also happen if the cursor is
deep and you increase scale.
If HPRF is active, you will see multiple Doppler gates on the reference image. If you do not want to be
in HPRF, decrease the scale or move the primary PW gate to a shallower location until only one gate
is displayed.
5.4 CW Mode
5.4.1. Using CW Mode
CW mode is only available on phased array transducer.
1. Perform the image scanning to get a good image in B mode or B+Color(DPI/DPDI) mode;
2. Press <CW> on the console to display sample line;
3. Use the trackball and touch controls to adjust the position of the sample line;
4. Press <CW> on the console to enter B+CW or B+Color(PDI/DPDI)+CW mode and display
Doppler strip.
5. Adjust image parameters to optimize the Doppler strip.
6. When spectrum is displayed, pressing <Update> toggles between acquiring the Doppler strip and
acquiring the reference image.
In CW mode, pressing on <PW> on the console will switch PW mode directly.
5.4.2. CW Image Optimization
The following touch controls can be used to optimize the CW image.
Name
Control
Description
Scale
Scale adjusts the range of velocities that are displayed. Upward
presses increase scale and downward presses decrease it.
Baseline
The Baseline control adjusts the Doppler baseline. Upward
presses move the baseline up on the screen and downward
presses move the baseline down.