Fig. 6.

Figure (a) shows a new polar baseline image that is transformed based on the center of a highly irregular lumen contour. The BVS struts in figure (a) still appear distorted and their thickness in the vertical direction is very different. Figure (b) demonstrates a follow-up image transformed based on the center of a circular lumen contour. The BVS struts are less distorted than these in figure (a). The detected candidate line segments (short white lines) are presented in both figures (c) and (d). Both white and black arrows point out the candidate segments caused by residual blood or noise in tissue. These candidates will be clustered as false candidate strut during the clustering. After the false positive removal, only real struts are left as figures (e) and (f) shows.