DAP reading when using the external collimator
When the external collimator is used, the collimator on the X-ray tube is
opened to cover the complete stitching grid height of 116 cm. The external
collimator reduces the exposed area to one third of the emitted X-ray beam.
This way, for each exposure, the measured DAP value is three times too high.
The DAP values that are received with the partial images or entered manually
are shown in the
Image Detail
pane of the
Examination
window. A
correction factor of 1/3 is applied internally to the DAP value. The corrected
DAP value is shown in the
View All
pane of the
Main Menu
.
The DAP value that is stored with the stitched FLFS image equals the sum of
the corrected DAP values of the partial images.
On NX software with version "Type 22.–" or older, the correction is not
applied, so the images will be stored with a DAP value that is three times too
high! Open
About NX
in the
Main Menu
to view the version number.
64
| Full Leg Full Spine DR Retrofit System | Advanced Operation
0326A EN 20211014 1141
