GE Voluson S6 Basic User Manual page 194

Doppler Modes
8.4.1 PD Main Menu
8-18
with slow flows can be seen (e.g. kidney, liver, prostate, etc.). This new technique is not
intended to replace established sonographic techniques, but to complete them especially in
the above-mentioned fields.
Advantages when compared to Color-Doppler:
•
less dependent on the incident angle
•
no aliasing
•
less dependent on the direction
•
wherever slow flows occur (e.g., blood circulation, veins, etc.)
Functional description:
In contrast to Color-Doppler, which displays the frequency shift of the reflection, Power
Doppler displays the amplitude of the reflected signal.The amplitude is determined by the
amount with respect to the blood cell aggregates collected by the measuring volume of the
ultrasound beam, and is thus less dependent on the angle between blood flow direction and
the incident ultrasound beam. As Power Doppler measures a different physical property to
color Doppler the color encoding is also different.
Power-Doppler imaging generates a Color image by using the Doppler principles. This Color
image is overlaid onto the B-image. The Power-Doppler image provides information about the
energy (Power) of the blood cell motion. The amplitudes of the Color Doppler signal are
evaluated and displayed with special color-coding. All velocity-determined functions (Baseline,
Scale, Display Mode, etc.) are not available in Power-Doppler imaging.
Power-Doppler can be combined with spectral Doppler. Power-Doppler is only possible with
electronic transducers.
The PD mode is subdivided in two groups. In these groups you will see how to use PD mode
and how to adjust the PD settings.
To use the PD mode: 'PD Main Menu'
page 8-21
To use special utilities: 'Utilities'
PD Mode key (hard key)
By pressing the control [PD] the PD mode is switched on. The PD Box appears on the active
2D image.
To use the PD mode: 'PD Operation'
on page 8-21
The [PD Mode] hard key is the Gain control for the PD mode (in scan mode only). 'PD
on page 8-19
Operation'
on page 8-18 To adjust PD setting: 'PD Sub Menu' on
on page 13-2 and 'Gray Map' on page 6-22
on page 8-19 To adjust the PD settings: 'PD Sub Menu'
Voluson® S6/S8 Basic User Manual
5433669-100 Revision 4