Gammex 403 GS LE, User Manual

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Measure the dimensions of the 6 mm cystic target to check the image geometry.
Use the calipers to measure from top to bottom and side to side. Repeat with the
other cystic target groups as part of the cyst imaging test.
9. Decrease image depth to the minimum and examine the dead zone target group.
The dead zone targets can be used to measure lateral resolution in the extreme
near field of the transducer.
Note : The highest dead zone pin you can see should
be the point of reference for all measurements – not the scanning surface.
10. Scan the four grey scale targets and observe the difference in their grey levels.
Adjust the gain control and observe how this affects the brightness of the targets.
Notice how noise in the anechoic target becomes apparent as the gain
increases. If your system has image “post-processing” capabilities, observe how
the contrast between targets changes with different settings.
Adjust the gain control to the lowest noise level. This is the point at which you
eliminate noise in the anechoic cyst (lower the gain until it just disappears).
Record this gain setting and use it for future grey scale measurements. Freeze
the image and visually evaluate the grey scale targets. Match each target with a
step on the grey bar in the image. Make a hard copy and compare the hard copy
with the image on the scanner.
11. When you are done scanning the phantom, empty the water dam or completely
clean off the coupling gel with a soft cloth or paper towel. Replace the cover and
secure by lifting the handle to protect the phantom.