Philips CARDIOMD, Service Manual

Page: 59 / 466

Calibration
1MAN0158-H11 04-2005 CSIP Level 1
CardioMD Service Manual
„
4-3
4.1 Introduction
This section describes all calibrations necessary to the CardioMD system.
4.2 Detector Calibration
4.2.1 Detector Calibrations Overview
All detector calibrations are performed electronically and activated by menu selections on the
acquisition PC.
Before starting calibration, make sure that high voltage has been applied for a period of time. If
power has been removed for more than a 15 minute period, the high voltage must be applied for
an equal period before calibration can be started. The maximum warm-up period required is 5
hours. The detector electronics must also have at least 15 minutes with the cover installed, to
reach operating temperature. Fluctuations in temperature (increase or decrease) can cause calibra-
tions to drift as the detectors reach operating temperature.
A complete calibration may be necessary after replacement of following detector parts:
•
EDC board
•
PMT
•
X-E board
•
Y board
•
Crystal.
A complete calibration of a CardioMD detector involves the steps listed in Table 4.1.
Note . The shaded rows indicate the calibrations required at time of installation.
# *) Calibration Equipment Isotopes
(point sources) Approx.
duration per
detector
1 HVCal (high voltage calibra-
tion) N/A N/A 3 min.
2 PMTCal (PMT basic calibra-
tion) Point source holder Tc-99m or Co-57
~ 40 MBq or 1 mCi 10 min.
3 Ecal (energy calibration) Point source holder Tl-201, Ga-67 or Ba-
133 and Tc-99m
~ 40 MBq or 1 mCi 5 min.
4 GeoCal (geometry calibration) MWSR mask,
4 collimated source
holders
4 sources, Tl-201,
Ga-67 or Ba-133
~ 4 – 12 MBq or
0.1 – 0.3 mCi each 5 min.
5 PMTCal update Point source holder Tc-99m or Co-57
~ 40 MBq or 1 mCi 5 min.
6 ECor (energy correction map
calibration) Point source holder Tc-99m or Co-57
~ 40 MBq or 1 mCi 30 min.
7 LinCor (spatial linearity map
calibration) Linearity phantoms
Point source holder Tc-99m or Co-57
~ 120 – 200 MBq or
3 – 5 mCi 60 min.