Two studies (Kiessling et al., 2015 and Schlaudraff et al., 2014) have shown pictures of cavitation bubbles from radial shockwave heads from a 6mm head (Kiessling et al., 2015) and a 36mm head (Schlaudraff et al., 2014).
Both took the images in a similar but not identical way:
Radial shockwave has direct and indirect effects on various structures (cells and hence tissues) throughout the body. Some of these effects are positive and some negative. There are many claims for the micro or cellular effects of shockwave. The ones which can currently be proven are explained here.
These micro structural or cellular effects often culminate together to have macro effects on actual parts of the body. These are generally referred to as the tissue effects of shockwave.