GE H
EALTHCARE
D
IRECTION
5158821-100, R
EVISION
3
E
X
PLORE
L
OCUS
SP S
ERVICE
G
UIDE
Page 160
Note:
The adjustment will change the ball’s geometric centre value 3 times faster when the stage is
at the X-Ray Source end compared to an adjustment when the stage is at the detector end.
If the value at the X-Ray Source is larger than the value at the detector end, turning the
adjustment wheel clockwise reduces the values. Small movements of the adjustment wheel
are required. One pixel will equal a few (1 to 5 degrees) turns of the wheel.
Once confirmed (i.e. the values of the 2 geometric centres are the same + or - 1 pixel):
33. Carefully tighten the 4 bolts (snug only) once the values are close. Make the bolts sufficiently
tight so that the adjustment wheel will operate but is difficult to turn. Tightening the bolts may
change the value of the geometric centres.
34. Complete the tightening of the 4 bolts and then verify the results at both ends. The bolts may
need to be loosened and retightened as you use the adjustment wheel to align the 2 values.
Once the 2 figures are again within 1 pixel of each other, the geometric centre of the ball (the value
of its x axis) is now the CENTRE OF ROTATION. Make note of this value in the Worksheet.
35. Save a captured image at both the detector end and the X-Ray Source end. Name the image
closest to the detector
smallball.vff
and the image closest to the X-Ray Source
largeball.vff
.
36. Turn off the X-Ray Source and exit
X-Ray and Motor Controller
.
7.3.3
Perform Verification Scans (1x1, 2x2, & 4x4 Modes)
The following procedure is used to verify the calibration settings.
Note:
The ambient temperature in the room must be stable to perform this procedure i.e. the room
temperature should not change even by 1 degree during the scanning process.
First perform verification scans for 1x1 mode using the procedure below, then repeat the procedure
in order to perform verification scans for 2x2 and 4x4 modes.
FIND THE IDEAL CENTRE OF ROTATION AT CENTRAL SLICE:
1.
Place the wire phantom in the small specimen tube, secure the phantom with foam, and mount
the tube.
2.
Ensure the filter wheel is set to
4
(or choose
1
for 4x4 mode).
Note:
Details concerning the following steps are found in the
eXplore Locus SP User Guide
. Refer to it
for particulars.
3.
Warm up the X-Ray Source, if needed.
4.
Once warmed up, launch
eXplore Scan Manager
.
5.
Click
Scan New Subject
and name the subject
1x1
(or
2x2
or
4x4
depending on which
verification scans are being performed).
Summary of Contents for Healthcare eXplore Locus SP
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