Appendix B – Cross-Calibration
B-7
STEP 4 - Re-label the QDR PHANTOM
Note:
This step is unnecessary if the customer intends to use the ORIGINAL PHANTOM to
perform daily QC measurements on the NEW QDR. It is only required if the customer
intends to use the NEW PHANTOM for daily QC on the NEW QDR system.
4.1 Enter “Biography” from the NEW QDR main menu and select “Spine phantom # xxxx
where “xxxx” is the number of the QDR phantom. (This Biography was created at the
factory).
4.2 Center the laser on the starting point of the QDR phantom and perform 20 array spine
scans of the QDR phantom using the NEW QDR:
SCANSQ -pap7sp60 -l6 -n20
4.3 Analyze these scans in the standard fashion as in Step 3.4.
4.4 Exit to DOS and type AVRSCAN <Enter> to obtain the average area, BMC, and BMD of
the 20 A/P Array Spine measurements of the QDR phantom. Select all 20 scans with the
<+> key and press <Enter>. Print the average values of the 20 scans.
4.5 Construct a label with the new area, BMC, and BMD values for the NEW PHANTOM
determined from Step 4.4. Remove the factory label and Affix the new label to the NEW
PHANTOM. This label should indicate that a “cross-calibration has occurred”.
4.6 From DOS type “FSCAL” <Enter> Choose option "n" from the FSCAL menu. The
program will display the array phantom number, the array Area, and the array BMC as
obtained at the factory. The “Array Phantom Number” should be modified to reflect the
QDR phantom number. The “Array Area” should be modified to reflect the AREA value
determined from Step 4.4 and the “Array BMC” should be modified to reflect the BMC
value determined from Step 4.4. Press <F10> to accept the modified values. Answer “Y’
to the query “Do you want to change PHANTOM.CAL[y/n] ?
4.7 Enter the height of the QDR phantom that was recorded earlier in Step 3.1f. Press <F10>
after the correct height for the QDR phantom has been entered.
Enter the measured height for phantom # xxxx : 6.78
4.8 Verify that the Array phantom information is correct and press “Y” to continue.
4.9 Add the scans from Step 4.2 into the QC database. Setup the QC database using the new
cross-calibrated results on the QDR phantom from the 20 scans performed in Step 4.2. QC
Setup is necessary because the calibration of the QDR has been changed from the factory
defaults due to the recalibration that occurred in Step 3.6f. Delete all the older factory QC
scans and the scans of the ORIGINAL PHANTOM from the QC database. Plot and Print
the A/P Array Spine Area, BMC, and BMD plots of the QDR phantom scans performed in
Step 4.2.
4.10 From the main menu choose Delete and use the <+> key to select all ORIGINAL
PHANTOM scans and QDR phantom scans except those just completed in Step 4.2. Press
<Enter> to delete all older spine phantom scans from the hard disk.
4.11
Reset the computer by pressing
<Ctrl><Alt><Del>.
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