Methods and apparatus for coding a visual representation of one or more plaque regions in a vessel are provided. The method includes segmenting the visual representation of the vessel to identify structures associated with the vessel, classifying at least one region in the vessel as a plaque region, displaying the at least one plaque region using a visual highlight selectively associated with the classification for the at least one plaque region, and shading the visual highlight based on a probability that the classification is correct.