Quantitative diagnosis of atherosclerosis can be facilitated by automatic segmentation of intravascular Optical Coherence Tomography (OCT) images. We report an automatic method of lumen and calcified plaque segmentation for commercial intravascular OCT systems. Lumen segmentation is based on a dynamic programming scheme. Calcified plaque is localized by edge detection and finely traced using an active contour model. The proposed methods yield promising results when applied to clinical images as validated by manual tracing. Lumen segmentation is useful for estimating the coronary artery stenosis and guiding stent implantation. Calcified plaque segmentation can be used to estimate the distribution of superficial calcification and inform strategies for coronary stenting.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.