5 Operating procedures
86500-IMG rev 3
GE Healthcare
43
5.10.3
Adjustment of the magnification factor
The window in the magnification tunnel design displays the current
magnification factor. It can be changed by pushing in the small lever in
the back of the tunnel frame and then lifting up or lowering the tunnel.
If you are using the spot magnification compression technique, ensure
that the area of interest is under compression and in the light field.
The small focus (0.1mm) is automatically selected for magnification
exposures. In magnification manual mode kV values starting from 20 kV
can be used.
5.10.4
Spot Magnification
Spot compression also compresses the breast more, thereby allowing the
use of a lower kV-setting, which results in improved image quality.
However, positioning using spot compression is more difficult to achieve.
X-ray beam should be
collimated to the
compressed area. This
reduces scattered radiation
to the image area, so
improving contrast and also
reduces the patient dose.
However, the final image
may be harder to read on
the viewing box due to the
density difference between
the exposed area of the film (the image) and the unexposed areas of the
film. The use of a mask for reading instead of exposing full image is
advisable.
Spot compression
applies local compression to a particular area. There is
less overlapping of tissue structures, which improves visualization.
NOTE!
Be careful when using spot compression as the compression effect is
greater on a smaller breast examination area.
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