In minimally invasive medicine, a stent is used to keep open an arterie or another hollow structure of the human body. The surface structure is of great importance.
What is a Stent? Read Wikipedia description.
The surface roughness of the stent is quite high: 440nm for a 20µm large image. Thus, the images can not be compared with those published in the technical note of molecular profiles. Nevertheless, a contrast difference in the phase image can be clearly identifiedView application note (PDF)