VDO MG 2100 Dokumentacja Pobierz pdf (Strona 330)

330 VisualSonics Vevo 2100 Imaging System Operator Manual Rev 1.1

Chapter 45: Acquiring Power Doppler Mode images

Beam Angle

Helps you generate flow direction information when the orientation of your target vessel

is perpendicular or almost perpendicular to your ultrasound beam.

This control applies a graduated series of transmission and reception delays to the

ultrasound sound signals of each crystal in the transducer. These carefully calibrated

sequences can effectively steer the ultrasound beam in order to detect minute frequency

shifts.

In PW Doppler Mode and PW Tissue Doppler Mode, the current beam angle setting is

displayed in the top-left corner of the B-Mode scout image.

In Power Doppler Mode and Color Doppler Mode, this changes the color box.

Active during Color Doppler Mode, Power Doppler Mode, PW Doppler Mode, PW

Tissue Doppler Mode imaging sessions.

To use this rocker switch control:

Push up or pull down the control depending on the orientation of your transducer to

steer the beam angle.

Priority

Determines the threshold point on the gray scale above which the system does not apply

color data. The red marker along the left side of the gray scale indicates the threshold

point.

Push up to assign more priority to the color data. Pull down to assign less priority to the

color data and more priority to the threshold on the B-Mode grayscale bar.

Useful when you suspect, for example, that color data is covering over the actual contour

of a vessel wall. In this case you would lower the priority until the overlay data matches

the actual tissue contour and properties.

Sensitivity

Adjusts the signal-to-noise ratio so that you can:

 Better identify weak-signal targets in the near field that are difficult to distinguish

because they are very small

 Better identify large targets in the far field that are difficult to distinguish because the

signal is so attenuated at depth.

The higher you set the sensitivity level, the lower the system sets the frame rate. Push up

to increase sensitivity. Pull down to decrease.

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VDO MG 2100 Dokumentacja Strona 330