17
Changes in the shape of the S-curve result in different brightness levels for the same
echo levels. Notice how the positions of the original brightness levels B–, Bo and B+
have moved to B–
1
, Bo
1
and B+
1
.
Changes in the system response can be identified by measuring the average pixel value
of the grey scale targets and the background material as displayed on the video moni-
tor. Pixel values can be estimated by eye or measured with image analysis tools
provided on some ultrasound instruments or computers equipped with video “frame
grabbers” and special software.
Summary of Contents for 403 GS LE
Page 1: ...403 GS LE Precision Multi Purpose Phantoms User s Guide...
Page 12: ...12...
Page 24: ...24 Notes...
Page 25: ...25 Notes...
