BK Medical bkSpecto, Руководство для продвинутых пользователей

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bkSpecto Advanced User Guide (16-01642-01) Imaging Modes 67
TGC
The TGC (Time Gain Compensation) curve determines variable amplification
applied to echoes from different depths in the tissue. The TGC function compensates
for attenuation and scattering of the ultrasound beam in the tissue.
When you select a transducer, if all TGC sliders are in the center position, imaging
starts using a default TGC curve optimized for the transducer. (The default is either
the one set at the factory or one you have set up yourself.)
The TGC sliders adjust the relative gain of the image at different tissue depths. Each
slider adjusts a specific part (1/8th) of the TGC curve; the topmost control adjusts the
top 1/8th of the image.
NOTE:
The sliders operate relative to their center position; when they are all
centered, the default TGC is used.
To adjust the TGC curve:
1
Tap TGC .
2
Slide the TGC sliders to the right or left to adjust the TGC curve.
The shape of the TGC curve is temporarily displayed to the right of the image
as a curved vertical line. This indicates the modification that is applied to the
default TGC curve.
To reset the TGC sliders to their central position:
•
Tap the Reset button.
By default, the TGC slider window disappears after 3 seconds.
NOTE
: The TGC curve operates on the monitor image, not on the ultrasound echo.
Therefore, if you move or resize the image, you may have to readjust the TGC curve.
NOTE:
With 360° transducers, the top slider adjusts the part of the image that is most
central – that is, closest to the transducer.
Auto Gain
You can also choose to use Auto gain. With Auto gain, a selected preset defines the
brightness for this particular type of scan (also depending on the transducer). Auto
gain makes it possible to have the same brightness across different patients and body
parts.
To activate/deactivate Auto gain:
•
Tap the Auto Gain parameter button to toggle between on and off:
Figure 7-4. The Auto Gain parameter button.
When you activate or deactivate Auto Gain , a message pops up bottom center of the
monitor informing you of the setting.