The present invention relates to annotating a medical image. For an improved manual insertion of information in a medical image, it is provided to display an image (130) of a tubular structure; and to display a graphical representation (132) of at least one segmented portion of the tubular structure; wherein the graphical representation comprises at least one indicator line representing the portion's shape and/or extension; and wherein the graphical representation is displayed in combination with the image of the tubular structure; and to generate and display at least one marker (128) overlaid to the image of the tubular structure; wherein the marker is movable (134) along the graphical representation; and to position the marker at a location along the graphical representation to indicate a predetermined feature of the tubular structure.
