Philips CARDIOMD, Service Manual

Page: 68 / 466

Detector Calibration
4-12
„
CardioMD Service Manual
1MAN0158-H11 04-2005 CSIP Level 1
Procedure Details
Note . An update is also required after per-
forming GeoCal.
Note . The customer will perform a PMT up-
date if a uniformity QC check is not accept-
able.
9. Click Continue.
Note . Automated motions must be started
from the patient load position.
10. Place the point source holder at a distance
of approximately 1.85 meters (6 ft.) from
the detector to be calibrated.
11. If Tc-99m is used, fill the glass vial to a
maximum of 2 cm. The surface of the liq-
uid must be below the top of the exposure
hole.
1
2
75
+/
- 3
c
m
185 +/- 3 cm 1
2
75
+/
- 2
c
m
185 +/- 3 cm
12. Place a Tc-99m or Co-57 point source of
approximately 40 MBq or 1.0 mCi in the
holder.
13. Make sure that the entire detector FOV is
exposed to the source and that the point
source is centered relative to the FOV.
14. Remove the collimator from the detector
to be calibrated.
Note . The detector undergoing PMT calibra-
tion must not have a collimator mounted.
15. Make sure that the entire detector FOV is
exposed to the source and that the count
rate is < 40 kcps.
16. When the source is in position, the colli-
mator removed and the count rate is cor-
rect, click Start to begin the PMT calibra-
tion.
The calibration goes through several iterations
while adjusting the gain of each of the PMT’s.