Hologic QDR 4500 - Page 247

Appendix B – Cross-Calibration
B-5
SCANSQ -pap7sp60 -l6 -n10<Enter>
d. Analyze the 10 scans manually with compare or use autocomp. To use autocomp,
analyze the first scan, exit to DOS and type:
AUTOCOMP 10 <Enter>
e. Verify that the BMD of the 10 scans is within +/- 2.0 % of the factory value written
on the label and that the CV is less than 0.5%. If the BMD is not within 2% or if the
CV exceeds 0.5%, recheck the installation process for possible errors or problems and
repeat the above set of 10 scans until both conditions are satisfied.
f. Make sure the printer of the NEW QDR is turned on and properly connected. Exit to
DOS and type:
PRINT \XCDATA\ARRC.TXT
Look for the line in arrc.txt which reads:
TO_N = 6.xx
where 6.xx is the ORIGINAL PHANTOM height in inches. This line is usually the
fifth line in the file. A common value is: TO_N = 6.78
Circle this line and write next to it “
QDR array phantom height
”, for use in Step
x.xx of the cross-calibration of the NEW QDR.
3.3 Use the NEW QDR to perform 20 Array Spine scans of the ORIGINAL PHANTOM.
First, select “Biography” from the NEW QDR main menu and create a new patient <Spine
Phantom # xxxx> where xxxx is the ORIGINAL PHANTOM serial number. Press <F10>
to save this patient biography. You may have to press <Esc> several times to create the
new biography because it may be similar to other biographies which already exist on the
NEW QDR.
3.4 Perform 20 A/P Array Spine Scans on the NEW QDR by exiting to DOS and typing:
SCANSQ -pap7sp60 -l6 -n20
3.5 Analyze the 20 scans from Step 3.3 manually using compare or with AUTOCOMP:
AUTOCOMP 20 <Enter>
3.6 Exit to DOS (<Alt> <F1>) and start the FSCAL program by typing "FSCAL” <Enter>
Note:
FSCAL
will not
accept anything less than 20 scans.
3.7 Modify the “phantom.cal” file by as follows:
a. 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 ORIGINAL PHANTOM
number. The “Array Area” should be modified to reflect the AREA value determined
from Step 1.1 and the “Array BMC” should be modified to reflect the BMC value
determined from Step 1.1. Press <F10> to accept the modified values. Answer “Y’ to
the query “Do you want to change PHANTOM.CAL[y/n] ?