3 Daily Quality Assurance
To ensure consistent image quality, establish and maintain a regular quality assurance program.
3.1 Tube Warmup
The system operates most efficiently within certain parameters. These parameters are
established by warming the tube using a preset group of exposures. When you perform a tube
warmup at least once every 24 hours and at any system prompt, it reduces the possibility of
image artifacts, and may aid in prolonging the life of the tube.
When you start the scan, a series of air scans are performed as part of the tube warmup scans.
3.2 Calibration
3.2.1 Daily calibration
The system requires that all kV and mA settings be within specific ranges. These ranges are
established and maintained by performing air calibrations. These calibrations are performed as
part of the daily system preparation following a tube warmup procedure.
Daily calibration (Fast Cal) must be performed every 24 hours to maintain image quality.
Daily calibration performs several automatic checks:
•
Tube Warmup, if needed.
•
The system confirms the gantry is in balance with a gantry balance check.
•
The system confirms the scan window is clean with a scan window check. If the scan
window is dirty or obstructed, it could lead to image degradation.
The system prompts you to clean it and remove any obstructions. Click [Retry] to repeat a
scan window check, or click [Continue] to proceed to Fast Cal without repeating the check.
The number of tube warmup scans depends on the current temperature of the tube.
The system finishes the Fast Cal procedure by performing a set of 3 scans.
3.2.2 Full system calibration
Full system calibrations are normally performed by a qualified Service Engineer following a tube
change or as part of preventive maintenance.
3.2.3 Non-GE X-ray tube
When the system is configured to use a non-GE X-ray tube or if the tube is unrecognized by the
system, an alert is posted during system startup, tube warmup, and fast calibrations that a non-
GE X-ray tube is detected in the system configuration. System configurations with non-GE X-ray
tubes will be noted in the Dose Report. A notification about using a non-GE X-ray tube will also
display in protocol selection and management.
Revolution CT User Manual
Direction 5480385-1EN, Revision 1
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3 Daily Quality Assurance
