Legend. Polarizationsensitive OCT images of atherosclerotic plaque showing high birefringence as seen by the rapid transition of the image from black to white corresponding to 0° to 180° phase retardation in a fibrous plaque (left) and low birefringence (right) in collagen-depleted plaque (right), confirmed histologically (bottom) by picro-Sirius red staining. See page 1476..