The effects of gating delays on ejection estimates: concise communication.

We have examined the effects of gating delays on the left-ventricular ejection fraction as measured by gated blood-pool studies. Patients with normal ventricular function were shown to have greater errors introduced by gate delays than those with poor function. The magnitude of the error depends on the shape of the ventricular time-activity curve. Actual delay measurements were performed on several commercial gates.