User Manual Part 2

101
2852 A EN 20070205
DRYSTAR AXYS
Performing the Weekly QC tests for general
radiography applications (DT 2 B and DT 2 C)
Spatial Resolution, Artifact Test and Low Contrast Visibility
To identify artifacts and verify spatial resolution you must perform the follow-
ing test weekly or as needed for troubleshooting image quality problems.
Procedure
1 First, print out the QC test image. Refer to “Performing the daily QC test for gen-
eral radiography applications (DT 2 B and DT 2 C)” on page 99.
2 Check the QC test image visually for artifacts: no significant disturbing artifacts
should be visible.
3 Check the spatial resolution in each of the three circles (refer to item 1, 2 and 3
on the “QC test image for general radiography applications (DT 2 B and
DT 2 C)” on page 90). Within each circle there are three groups, each consisting
of five dots. All five dots of each group must be visible with a magnifying glass.
The smallest cluster of 5 dots is only visible if the viewing conditions are good.
4 Check the Low Contrast Visibility at both the high (100 / 95%) and low end
(0 / 5%) of the density scale. You should be able to see the circle in the square
(refer to item 1 on the “QC test image for general radiography applications
(DT 2 B and DT 2 C)” on page 90 and the upper circle (refer to item 2 on the
“QC test image for general radiography applications (DT 2 B and DT 2 C)” on
page 90).
5 Record these values on Chart 3 (‘Drystar AXYS Artifacts and Spatial Resolution
Control Chart’).
WARNING: Good viewing conditions are important for the correct
interpretation of both diagnostic and test images. Make sure that the light
box intensity (luminance) is between 2000 and 4000 cd/m² (4500 and
6500 °K). Use a magnifying glass and use shutters to collimate. Make sure
the ambient light is low.