Terason t3000, Руководство пользователя

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Chapter 5 - Working With Scan Modes Using Color and Power Doppler Image Controls
Terason t3000 / Echo Ultrasound System User Guide 122
Effects of the Color Invert Button
Notice that the colors on the reference bar are also inverted.
The figure above should be viewed in color; when printed in black and white, the effect
may be obscured.
Adjusting the Wall Filter
Doppler systems use a wall filter (high pass frequency filter) to eliminate unwanted low-
frequency, high-intensity signals (also known as clutter) from the display. Clutter can be
caused by tissue motion or by rapid movement of the transducer.
Raising the wall filter setting reduces the display of low velocity tissue motion. Lowering
the wall filter setting displays more information. However, more wall tissue motion is also
displayed.
The wall filter setting should be set high enough to ensure that Color Doppler flash
artifacts from tissue or wall motion are not displayed, but low enough to display slow
flow. If the wall filter is set too high, slower flow may be not seen.
Set the wall filter setting higher for applications where there is significant tissue motion
(such as cardiac), or in instances where the transducer is moved rapidly while scanning in
Color Doppler mode. Set the wall filter setting lower for small parts or instances where
flow is slow but there is not much tissue motion.
Use a wall filter setting that is high enough to remove clutter but low enough to display
Doppler information near the baseline.
To adjust the wall filter value, drag the slider to the right for increased filtering, or drag the
slider to the left for decreased filtering.
Wall Filter Control
The wall filter range is from 1% to 25% of the PRF.
Adjusting the Color Gain
Color gain can be increased to correct an inadequate fill of color within a vessel, and
decreased to correct an unacceptable amount of color outside of a vessel.
You can adjust the color gain to increase or decrease the amplification of the returning
signal being played or displayed.
Color Invert Not Selected Color Invert Selected