Computer assisted three-dimensional plaque characterization in intracoronary ultrasound studies

The volume, morphology and composition of atherosclerotic plaque play an important role in coronary artery disease and in long-term outcome of coronary interventions and pharmaceutical strategies. Intracoronary ultrasound (ICUS) provides real-time cross-sectional imaging of vessel wall structures. In-vitro and in-vivo studies have shown that ICUS can identify the general composition of the plaque by assigning different grey levels to different tissue types. Ultrasound scanners use 256 grey levels, whereas the human eye can only discriminate 32. Therefore, computer-assisted grey level interpretation (labelling) and measurement can help identify different tissue types present in the plaque and track changes over time. This paper covers a new research tool that facilitates this and that provides an objective quantitative analysis parameter for the segmentation of plaque into four different tissue types.