Have attached one of the Dutch reports and yes its in Dutch you can make reasonable sense out of it with auto translator, but I'm quessing you'll be more intersted in the two stem photos.
The troubling and confusing tomographs are totally meaningless (to me) and I'm sorry but htat is my experience with picus generally....and yes I do accept some of you will have much better experiences of using that technology than me.
vervolgonderzoek%20Anne%20Frankboom%202007%20-%20PFBA.pdf