GE Senographe DS Manual page 702

GE Healthcare
Revision 1
Job Card ELE A032 – IQ Tools Flat Field Test
9-3 Bad Pixels or Bad ROI test fails
WARNING
One Defect category FAIL means that the detector is above the GE Bad Pixel specifica-
tions. The root cause of the failure must be found before the customer can use the system
for clinical use. If the customer uses a detector having more Bad Pixels than allowed there
is a risk to loose information in the clinical images.
If Bad pixel or Bad ROI tests fail, do no change the Flat Field Phantom before performing the
3-1, section 9-3-2 and
9-3-1 Check if Dust is present on the image receptor
Ensure the image receptor is completely clean and run the test again.
9-3-2 Dust is present on the light beam alignment mirror or on the Mo filter
Clean the mirror and Mo filter without direct contact according to the directions in
Collimator and Tube Head Cleaning on page
found, it is recommended to install the Dust reduction kit (P/N 5394527) to reduce this problem occur-
rence.
9-3-3 Check if the flat field phantom is the root cause of the issue
1. Clean the Flat Field Phantom to avoid any dust on it, use water if required but no chemical product.
2. Run the Flat Field Test, locate the bad ROIs or bad pixels, adjust the viewing contrast to make the
spot visible.
3. Move the Flat Field Phantom slightly, run the Flat Field Test again and note whether the bad ROIs or
pixels have moved. Use the mouse middle button to adjust contrast and brightness such that window
width WW is less than 200. If necessary, take the images in the Medical Application and use the
AWS display tools.
4. Check the position of the detected bad pixel, and determine your next step:
• If the bad pixels are at the same position the Flat Field Phantom is not responsible for the test fail-
ure and does not need changing. Continue the troubleshooting in
• If the bad pixel followed the Flat Field Phantom positioning, the phantom is the cause of the test
failure. Ensure that this phantom is free from dust (pay specific attention to the part that covers
the bad pixel area in the image), you may repeat the test again after cleaning. If bad pixels are still
at the same position, you will need to change the flat field phantom. Change the Flat Field Phan-
tom and redo the test without performing any calibration.
Chapter 7
section 9-3-3 of this troubleshooting guide.
Service Information and Procedures Class A 2385072-16-8EN
1787. Then run the flat field test again. In case dust is
Page no. 702
Senographe DS
section 9-
Job Card PM A255 -
section 9-3-4.
JC-ELE-A-032.fm