How do the microdiamonds highlight abnormalities, and not just whatever it rests on? That is, wouldn't you simply get the same signal to noise ratio as before?

How do the microdiamonds highlight abnormalities, and not just whatever it rests on? That is, wouldn't you simply get the same signal to noise ratio as before? Not only that, wouldn't the signal strength be a function of blood supply to that area? Thus, how big does the abnormality have to be before its conclusive using this technology?