Fig. 7.

(A) Example of using the semi-quantitative method to evaluate iron degradation of an 8 mm long iron-based scaffold and present the spatial location of struts with identified different degrees of degradation (0% in grey rectangle, partially degradation in light yellow rectangle, and 100% degradation in brown rectangle) in an unfolded scaffold state, from 3-dimensional OCT video to 2-dimensional (cross-sectional) OCT frames and then to each strut cross-section. (B) Comparison of the results by the semi-quantitative OCT method to those by the widely-used weighing method with nine samples of representative weight losses ranging from 1.5 wt% to 96.7 wt%.