GE LOGIQ 500 Advanced Reference Manual page 179

Penetration
Description
Benefit
Method
Procedure
.
LOGIQ 500 Advanced Reference Manual
2276614–100 Rev. 0
Penetration is the ability of an imaging system to detect and
display weak echoes from small objects at large depths. Refer
to Figure 5–1 on 5–5 for details.
Penetration can be affected by the system's:
S
Transmitter/receiver
S
Degree of probe focusing
S
Attenuation of the medium
S
Depth and shape of reflecting object
S
Electromagnetic interference from local surroundings.
Weak reflecting echoes are commonly produced from the
internal structure of organs. Definition of this tissue texture is
important in the interpretation of the ultrasound findings.
Scan a phantom to see how echoes begin to fade as depth is
increased. The maximum depth of penetration is the point at
which homogeneous material in the phantom begins to lose
brightness.
To measure penetration:
1. Set the front panel TGC slide pots to their center
(detent) position.
2. Gain and acoustic output can be adjusted, as
necessary, since these values are displayed on the
monitor.
3. Scan a test phantom along the vertical pin targets to
typical depths for the probe being used.
4. Perform a standard distance measurement from the top
of the image displayed to the point at which
homogeneous material in the phantom begins to lose
brightness.
5. Document the depth measurement for reference and
future comparison.
Contact a Service Engineer if the depth of penetration shifts
more than one centimeter (1cm) when using the same probe
and same system settings.
Quality Assurance
5–13