The skull is blocking the soundwaves in adults. In fetal ultrasound the brain and intracranial blood vessels are routinely examined, since the bone is thinner, less dense and the fontanelles aren't set.

You really need to brush up on your basic knowledge of ultrasound since it is very obvious that bone is echo-dense.

Hi Sara,

I disagree with Rasmus, he doesn't seem to be informed about the use of sonography in Neurology. It is called transcranial sonography and is widely used e.g. for the Substantia nigra for the diagnosis of Parkinson's disease (Article Echogenicity of the Substantia Nigra: Association With Incre...

Find examples:

https://www.google.com/search?tbm=isch&q=transcranial+sonography&spell=1&sa=X&ved=0ahUKEwjK_u3QgoHYAhWGS98KHc1nDqYQvwUIJCgA&biw=1920&bih=949&dpr=1

Nevertheless, the use is limited depending of the question that you are posing.

Best

Julian

Indeed, there have been remarkable innovations in the use of ultrasound (US) for brain imaging in the past few years, as well as US for brain stimulation and ablation. These were never thought possible due to bone being echo-dense, but redesigning US arrays and using different frequencies are overcoming this obstacle. See work by Tyler, Tufail, Yilmaz, de Souza Daw, Hynynen, Hameroff, and others.