Accuracy of Measurements
Distance measurements on DR Full Leg Full Spine images in NX are displayed
with a resolution of one or more decimal places (such as 0.01 cm). You should
be aware that the real measurement accuracy is generally considerably lower
for a number of different reasons, many beyond the control of the product.
Distance measurements can be calibrated based on the Estimated
Radiographic Magnification Factor.
The measurement accuracy is limited by at least four factors:
• The quality and nature of the input data, including but not limited to the
accuracy of the calibration values.
• The user's ability to select appropriate points on the screen.
• The transformations inherent in generating images on a finite pixel
display.
• The stability of the patient during the examination.
It is the user’s responsibility to understand these limitations and to use the
measurement tools responsibly.
For the distance measurements on DR Full Leg Full Spine images, the accuracy
is 0.2 cm. The accuracy applies to the difference between the size of the
projection of the object on the stitching grid and that measured with the
product, on these conditions:
• The image is stitched based on the grid markers.
• The object has not moved during the examination.
• No pressure is applied on the stitching grid, causing it to bend.
WARNING:
If the patient leans against the stitching grid, the bending of the
grid will decrease the accuracy of length measurements.
WARNING:
The system cannot predict the impact of patient movement or of
inaccurate input data on the accuracy of a measurement done
on anatomical parts.
The user is responsible for observation of the movement of the
patient during the examination. Such movement influences the
accuracy of measurements when using the anatomical stitching.
Perform the quality control of stitched image as described in the
basic workflow and take into account vertical and horizontal
correction in stitching zones when performing measurements.
Related Links
on page 47
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| Full Leg Full Spine DR Retrofit System | Introduction to the Full Leg Full Spine application
0326A EN 20211014 1141
