GE LOGIQ 500 Advanced Reference Manual page 177

Axial resolution
Description
Benefit
Procedure
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LOGIQ 500 Advanced Reference Manual
2276614–100 Rev. 0
Axial resolution is the minimum reflector separation between
two closely-spaced objects to produce discrete reflections along
the axis of the sound beam. It can also be monitored by
checking the vertical size of known pin targets. Refer to
Figure 5–1 on 5–5 for details.
Axial resolution is affected by the transmitting section of the
system and the probe.
In clinical imaging, poor axial resolution displays small
structures lying close together as a single dot. This may lead to
improper interpretation of the ultrasound image.
To measure Axial resolution:
1. Scan a test phantom with precisely-spaced vertical pin
targets.
2. Adjust all scan controls, as necessary, for the best
image of the pin targets to typical depths for the probe
being used.
3. Press Freeze to stop image acquisition.
4. Perform a standard distance measurement of the pin
vertical thickness at different points in the image.
Record all images for archiving.
5. Scan the vertical pins in zoom or at different
depth/scale factors.
6. Press Freeze to stop image acquisition; repeat the
vertical thickness measurements of the pins and record
the images for archiving.
7. Document the measurements for reference and future
comparison.
Axial resolution should remain stable over time. Contact a
Service Engineer if any changes are observed.
Quality Assurance
5–11