11
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.
Summary of Contents for 404GS LE
Page 1: ...404GS LE Precision Small Parts Grey Scale Phantom Gammex User s Guide...
Page 13: ...13...
Page 24: ...24 Notes...
