Hologic QDR 4500 - Area, BMD, and BMC Calibration Stages

Section 4 - Alignment & Calibration
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28. Press <PrintScreen> to make a hard copy of the scan.
The following conditions must be met:
•
The posterior elements of the spine must be clearly and completely visible on the
left side of the scan.
•
If there is a black stripe on the extreme left edge of the scan, the collimation and/or
flattening is incorrect; notify Hologic Customer Service.
•
Refer to the printout. Below the scan, the ROI location is indicated as "##x## at
[nn, ##]" where nn is the distance from the left side of the scan to the ROI. There
should be 7 channels, or less, distance between the left edge of the scan and the
edges of the posterior elements of the spine. The "nn" is the number of channels
from the left edge of the scan, and should be less than, or equal to, 7.
AREA, BMD AND BMC CALIBRATION
Calibration for Area, BMD and BMC is accomplished in 3 stages:
a) Array Scan Thickness Measurement & Calibration
b) Calibration of Area and BMC, for Array Scan Modes
c) Adding Array AP and Fast lateral scans to the QC database
Follow the procedure, in order, and exactly as shown, for each stage of the calibration.
Note:
If the QDR 4500 being installed is to replace an existing QDR (model 2000
plus
, 2000,
1500, 1000
plus
, 1000 or 1000/W) then a cross-calibration must first be performed to
ensure that any longitudinal studies begun on the QDR being removed can safely be
continued on the new QDR 4500.
Perform the cross-calibration before de-installing the
existing QDR.
Note:
To ensure stability, the machine must be completely powered up for a minimum of
30
minutes
prior to running any of the following tests. Also, because the table top pad will
have a slight affect on the test results, all scans
must
be performed with it in place.
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.
Scan Thickness Measurement & Calibration
(QDR 4500A and SL)
1. From the QDR patient menu, select the spine phantom to be used for checking the array
scan modes. This should be the one shipped with the machine.
Note:
Be sure the spine phantom has been entered in the patient database in the form of "Spine
Phantom #
nnn
" (where
nnn
is the number of the phantom) so that the QC plot program
can identify it properly.