GE Revolution CT User Manual

5 Auto Gating
Auto Gating is a feature designed to optimize ECG-gated acquisition settings based on an
assessment of patient heart rate and variability, primarily focused on exams of the coronary
arteries. A similar feature on Discovery CT750 HD is referred to as SnapShot Assist. The Auto
Gating workflow provides the capability to record heart rate statistics during a breath hold to
determine the acquisition settings best suited for the heart rate characteristics of the patient.
For example, at higher heart rates, end-systolic phases are usually preferred due to the lack of
a diastasis period in mid-diastole. Auto Gating automatically uses heart-rate specific acquisition
settings (called “profiles”) from predetermined lookup tables.
A patient's heart rate can change over the course of a cardiac examination and result in
suboptimal results if adjustments are not made prior to the diagnostic cardiac CT scan. A
patient's heart rate should be assessed throughout an exam to watch for heart rate changes.
Consider the following factors that can impact a patient's heart rate during Coronary CT
Angiography (CCTA). These factors should remain consistent between the practice breath hold
and the gated cardiac exam to ensure that the pre-scan heart rate assessment is accurate.
•
Breath Hold Technique — end inspiration, mid inspiration, suspended breathing, et certera
•
Time Delay — after the breath hold command
•
Contrast — total volume, injection rate
•
Beta Blockers — oral and or IV
•
Vasodilators — can lead to slight increase in heart rate
•
Patient aspects — sex, age, electrophysiological disease, cardiac function issues
5.1 Auto Gating Acquisition Settings
Auto Gating generates suggested scan settings using the selected profile based on the patient's
recorded heart rate and selected Auto Gating profile (GE Adult Coronary). It uses the patient's
recorded heart rate information to predict the heart rate behavior during a CCTA scan to
optimize the parameters for each patient. You can acquire a recording automatically during scan
acquisition (timing bolus, calcium scoring series, etc.) or manually during a practice breath hold
by using the
Record New HR option in the Acquisition Window and Heart Rate widget.
Illustration 13: Acquisition Window and Heart Rate widget
An alert message will be given under the following conditions:
Revolution CT User Manual
Direction 5480385-1EN, Revision 1
356 5 Auto Gating

GE Revolution CT Specifications

General

Brand	GE
Model	Revolution CT
Category	Medical Equipment
Language	English