An automatic or semiautomatic method of processing intravascular Optical Coherence Tomography (OCT) images, comprising: pre-processing the primary image by segmenting the guidewire in the lumen to exclude it from the image, determining whether the lumen is open or closed if the lumen is determined to be closed, performing a first automatic lumen segmentation procedure on the pre-processed image to define a perimeter line of the lumen, corresponding to the inner edge of the vessel wall, and determine a centroid CL of the lumen area if the lumen is determined not to be closed, sequentially performing an automatic lumen closing procedure on the pre-processed image, and a second automatic lumen segmentation procedure, to define a perimeter line of the lumen, corresponding to the inner edge of the vessel wall, and determine a centroid CL of the lumen area automatically finding an outer edge of the vessel wall and defining a first region of interest ROI1 between the inner edge and the outer edge of the lumen automatically segmenting a fibrous plaque in the first region of interest ROI1 thereby defining a second region of interest ROI2 that contains the fibrous plaque, and segmenting a hyporeflective plaque, contained in a radial region that falls within ROI1 and is external to ROI2.
