Chapter 5 - Working With Scan Modes
Using Spectral Doppler Image Controls
Terason t3000 / Echo Ultrasound System User Guide
114
Adjusting the Sample Volume (SV) Size and Depth
The sample volume size control adjusts the size of the Doppler region being examined.
The lower the value, the narrower the sample size used in the calculation of flow velocity.
The sample volume displays along the ultrasound cursor as two parallel lines. The
distance between the two parallel lines is the size of the sample volume in millimeters.
To adjust the sample volume (SV) size, click the SV Size right arrow to increase the
volume or the left arrow to decrease the volume.
Sample Volume Size Control
You can set a value from 0.5 to 20 mm (in 0.5 mm increments). The value shows on the
image display if Probe Info is enabled. You can also use the indicator to move the depth of
the sample volume along the ultrasound cursor. To do so, click the indicator and move it
up or down until it is located properly, then click to lock the indicator in position.
You can adjust the position of the sample volume using the touch pad or mouse. Left-click
the sample volume (the line turns green), move it to the desired location, and left-click
again to anchor it.
If the sample volume is not moved for five seconds, it is anchored in position. You can
also use the left and right arrow keys to move the ultrasound cursor, and the up and down
arrow keys to move the sample volume indicator.
You can only use this control when viewing a live image. When an image is frozen, you
cannot adjust the sample volume.
Modifying the depth location of the sample volume affects the Thermal Index (TI) value
(refer to
General Description of Indices
on page 268 for more information about thermal
indices).
Setting the PWD Gate Position
The sample volume indicator allows you to start a scan in a 2D scan mode, set the sample
volume at the indicator location, and switch to Spectral Doppler mode. The sample
volume locks in position. When scanning in CD, DirPwr, or Pwr scan modes, this
procedure switches to Triplex mode (if enabled by your license).
To locate the sample volume and switch to PWD or Triplex mode, you can double-click at
the location in the 2D window to automatically set the gate position and switch to PWD or
Triplex scanning.
The following procedure also sets the gate position and switches to PWD or Triplex
scanning:
1.
Select the scan mode and adjust all Image Control settings appropriate for the current
exam.
2.
Place the Windows pointer inside the vessel of interest. You can use the Zoom tool
(see
Enlarging an Area of the Image
on page 73) for more precise pointer placement.
3.
Right-click the vessel of interest. The shortcut menu opens.
