Fig. 1.

Fluorescence optical imaging (FOI) staining in a healthy subject. Upper image: initial enhancement (IE), defined as the first strong signal of indocyanine green (ICG), in digit II of the right hand; IE in the left hand has already taken place. Middle image: area of maximum distal distribution (MDD) is the fingertip (region 0) in every finger as this is the most distal region with a sufficient ICG signal. Lower image: last image (no. 360) of the examination; most of the ICG has already disappeared