Retrospective image‐based gating of intracoronary ultrasound images for improved quantitative analysis: The intelligate method

Quantitative analysis of intracoronary ultrasound (ICUS) studies is performed on a series of tomographic cross‐sectional ICUS images acquired during a motorized 0.5 mm/sec catheter pullback. Catheter displacement in the vascular lumen during the cardiac cycle causes an anatomically shuffled ICUS study, which results in a sawtooth‐shaped appearance of the coronary segment in longitudinal reconstructed views in quantitative coronary ultrasound software packages. This hampers contour detection and leads to a laborious time‐consuming semiquantitative analysis process that may produce inaccurate results. To solve these problems, in the past, online ECG‐gated acquisition hardware has been applied. This article describes a novel image‐based gating method called Intelligate, which features automatic retrospective selection of end‐diastolic frames from videotaped or digitally stored ICUS studies. Our evaluation shows that there are no quantitative differences between analysis results of hardware ECG‐gated and Intelligated ICUS studies. Catheter Cardiovasc Interv 2004;61:84–94. © 2004 Wiley‐Liss, Inc.