colleagues predicted this will not be possible because the skull is so thick we got very very encouraging data so we got a image that shows certain structures which match the structures in the photograph very well the next big step is to push this to in vivo imaging of human brain unlike x-ray CT which always works in transmission mode because x-ray doesn't scatter much further acoustic waves propagate essentially in all directions so that means we're very flexible in terms of actually implementation I just talked about the circular geometry for