User Manual Part 2

113
2852 A EN 20070205
DRYSTAR AXYS
Verifying Acceptable Spatial Resolution and
Artifact Levels and Low Contrast Visibility for
mammography application (DT 2 Mammo)
(optional)
Procedure
1 Print the QC mammography test image or use the previously printed QC mam-
mography test image used to establish the daily operating density levels.
2 Visually check the QC test image for artifacts: no significant disturbing artifacts
should be visible.
3 Check the spatial resolution in each of the three ovals. Within each oval there
are three groups, each having five dots. All five dots of each group must be visi-
ble 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 mammography applications
(DT 2 Mammo) (optional)” on page 107) and the upper circle (refer to item 2
on the “QC test image for mammography applications (DT 2 Mammo)
(optional)” on page 107.
5 Record these values at the top of Chart 3 (‘Drystar AXYS Artifacts and Spatial
Resolution Control Chart’).Refer to “Charts for mammography QC (optional)”
on page 155.
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 3000 and 6000 cd/
m² (4500 and 6500 °K) for mammography. Use a magnifying glass
and use shutters to collimate. Make sure the ambient light is low.