Arrhythmia Monitoring

The name of this CV varies depending on the selected PSD:

Use the Arrhythmia User CV when scanning patients with erratic heart rates or if the gating signal is poor.

With standard QRS detection algorithms, arrhythmic heartbeats can be mistaken as normal QRS complexes. This is undesirable for cardiac-triggered exam. With the Arrhythmia Monitoring, you can compensate for an irregular heartbeat.
The function of each setting is determined by the setting of the Auto # of cardiac phase button.

FastCINE mode

Compatible with FastCINE PSDs when the Prospective button on the Cardiac tab is not selected.

Arrhythmia Rejection: 0 = off: The default selection for Arrhythmia Rejection accepts every ECG trigger as a valid trigger for acquisition, regardless of the Arrhythmia Rejection Window value entered on the Cardiac tab. In other words, no heartbeats are rejected and the scan time does not change. If there are arrhythmias, the image quality is compromised.
Arrhythmia Rejection: 1 = threshold off: The Arrhythmia Rejection is on and the threshold is off. If a trigger is detected outside of the Arrhythmia Rejection window set on the Cardiac tab, the system discards the data from the current cardiac cycle, then waits for the next valid ECG trigger to reacquire the data. The scan is not completed until all the data is acquired (all k-space is filled). This can lengthen the total scan time, but it can improve image quality by rejecting data with incorrect triggers. The scan is never aborted because of too many rejected triggers.
Arrhythmia Rejection: 2 = threshold on: This method is the same as method 1, except that the system keeps track of the number of arrhythmias and aborts the scan if the number of arrythmias exceeds the threshold. Up to 8 arrhythmias (triggers outside the window) are allowed for scans shorter than 25 seconds (a typical breath hold acquisition), and up to 20 are allowed for scans longer than 25 seconds.

Compatible with the same PSDs as in FastCINE mode except that the Prospective button on the Cardiac tab is selected.

Perform Arrhythmia Monitoring: 0 = off: Arrhythmia Rejection is on and the threshold is off. If a trigger is detected outside of the Trigger window set on the Cardiac tab, the system discards the data from the current cardiac cycle, then waits for the next valid ECG trigger to reacquire the data. The scan is not completed until all the data is acquired (all of k-space is filled). This can elongate the total scan time, but it can improve image quality by rejecting data with incorrect triggers. The scan is never aborted because of too many rejected triggers.
Perform Arrhythmia Monitoring: 1 = on: This method is the same as method 0, except that the system keeps track of the number of arrhythmias and aborts the scan if too many are detected. Up to 4 arrhythmias are allowed for scans shorter than 25 seconds (a typical breath hold acquisition), and up to 10 are allowed for scans longer than 25 seconds.