CAUTION
Patient motion, respiration, beat-to-beat variability of heart rate, heart motion, or
significant change in heart rate over the scan duration could cause an ECG
gated acquisition to have degraded image quality. It is important to explain to the
patient the pattern of breathing instructions to expect, the warm feeling that can
be felt from the contrast injection and to position the patient comfortably such that
the arms will not move with respect to the body during the scan. Heart rate
information and phase location will be updated to indicate any movement of
trigger locations since heart rate and phase values are calculated based on time
between consecutive triggers and are not diagnostic values.
CAUTION
Ensure the ECG patches are not past expiration date and that the gel on the
pads is still moist for proper conduction of the ECG signal for successful gating.
CAUTION
There is a possibility that the ECG signal may not be detected by the scanner
due to improper lead placements, or a lead falling off during the scan. It is
important to place new leads on the patient before the scan. Make sure the leads
are attached properly, and use only GE recommended ECG leads. It is important
to confirm ECG trace clarity before the scan.
CAUTION
If during the scan the heart rate drops significantly lower than the prescribed
heart rate, there is a potential for gaps in the gated image location. To avoid
image location gaps, a non-gated image is reconstructed for the period where the
patient heart rate dropped below the expected or confirmed heart rate at the start
of the exam. A non-gated image may have more motion and may not be
reconstructed at the prescribed phase.
CAUTION
Manual edits of the ECG gating waveform may be performed retrospectively in
some ECG gated exams as long as scan data exists on the console. Images can
be reconstructed with user modified gating triggers and the original gating
information can be retrieved after edits have been made.
WARNING
CURVED AND LUMEN REFORMATION CAN INTRODUCE DISTORTIONS IN
THE SHAPE OF OBJECTS.
Revolution CT User Manual
Direction 5480385-1EN, Revision 1
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14 Application Specific Safety Topics
