Siemens MAMMOMAT Inspiration - Detector Uniformity Performance Criteria

Test 3: Detector Uniformity
24 Quality Control Manual
SPB7-330.640.01.01.02
7. Define an ROI with a size of approximately 20 x 20 mm
2
in arbitrary position
inside the image.
8. Move this ROI subsequently to each of the five positions indicated in Figure 3. If
helpful switch off image text, menu View > No Text.
Figure 3 ROIs on the detector
9. For each of these five ROI positions note the corresponding mean pixel value in
Test form Test 3.
10. Calculate global average of mean pixel values over all five ROIs.
11. For each ROI calculate relative deviation from global average (see Relative
deviation from corresponding average, page 13).
12. Identify and note the maximum relative deviation out of the results from step 11.
13. Repeat steps 6 to 12 for target/filter combinations Mo/Rh and W/Rh.
14. Close examination.
Performance Criteria and Corrective Action
The maximum relative deviation from global average should not exceed 7 %.
2
5
3
1
4
2 cm
2 cm
2 cm
2 cm