Hologic DISCOVERY A, Technical Manual

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Discovery QDR Series Technical Manual
4-35
Note: To ensure stability, the instrument must be completely powered up for a minimum
of 30 minutes prior to running any of the following tests. Also, because the
tabletop pad will have a slight affect on the test results, all scans must be
performed with it in place.
4.14.1 Scan Thickness Measurement & Calibration (C and
W)
1. Press the Center Table button.
2. Turn on the laser.
3. With the laser on, place the phantom so that the laser dot is on the centerline of
the phantom, 1/2" from the left end, shining on the phantom target. The sides of
the phantom should be aligned parallel to the table, using a ruler if necessary.
4. Be sure the spine phantom has been entered in the patient database in the form of
"Spine Phantom #nnnn" (where nnnn is the number of the phantom) so that the
QC plot program can identify it properly.
5. From the Discovery Main Menu screen, select
Perform Exam
, select the Spine
Phantom, and click the
OK
button at Patient Information dialog box.
6. Select
AP Lumbar Spine
, uncheck default scan check box, and click the
Next>
button.
7. Select
Array
, click the
Next>
button, set the scan length to 6 inches, and start
the scan.
8. Analyze the scan and click the
Close
button to exit the Analysis screen.
9. Start the Field Service Calibration program by selecting
Utilities|Service Utili-
ties|Field Service Calibration
from the Discovery Main Menu screen.
10. Select the Spine Highs/Lows for Array Spine phantom option to automatically
calculate the new thickness indicators for array spine.
11. Select the Spine Phantom scanned in step 6 from the list of Analyzed Scans and
click the
Next
button. Click the
Continue
button on the Successfully Calcu-
lated message box.
12. Click on the Temp Write button and click the Continue button on the Success-
fully Wrote message box. Exit Field Service Calibration.
WARNING: X-rays are produced during most of these tests. Keep hands, head and other body parts
out of the X-ray beam path. The tester should also be wearing an approved radiation
dosimetry badge.