Volumetric intracoronary ultrasound

Three dimensional analysis using intracoronary ultrasound (ICUS) pull-back data provides the unique ability to quantitate lumen and atherosclerotic plaque volumes. Unlike x-ray angiography which measures only the lumen, ICUS provides direct information about plaque volume distribution. ICUS volumetric analysis is required in order to understand mechanisms of coronary interventions, restenosis, and regression. In this study we developed and validated volumetric ICUS methodology.;In the first part of the study, optimal data acquisition parameters for volumetric acquisition were established using simulations on computer phantoms of stenotic arteries. Eleven computer phantoms were generated using cross-sectional area data from quantitative angiography of stenotic coronary arteries. Three methods of data acquisition were simulated: conventional manual pull-back; motorized pull-back; and manual pull-back with measured displacement. Effects of pull-back velocity and cardiac gating on cross-sectional area profiles and volumes were studied. We rated the methods, measured ;In the second part of the study, we developed a real-time, ICUS pull-back data acquisition scheme to acquire calibrated, cardiac-gated 3D image data sets. A semi-automated border detection scheme was implemented using dynamic programming. To validate the ICUS methodology, multiple pull-backs were performed in phantoms. ICUS volumes were very reproducible (;We conclude that volumetric ICUS provides accurate and reproducible estimates and, unlike angiography, provides a direct in-vivo technique for quantifying atherosclerotic plaque volumes. The technique will have direct clinical applicability in regression and restenosis trails.