Cerebral aneurysms and arteriovenous malformations.

Cerebral aneurysms and arteriovenous malformations (AVMs), including arteriovenous fistulae, are rather seldom investigated by means of transcranial color-coded duplex sonography (TCCS). Nevertheless, the continuous improvements in high-quality scanners, ultrasound contrast enhancers, and special software, such as three-dimensional reconstruction tools, make these lesions assessable in a high number of patients. In particular, the possibility of investigating hemodynamics and hemodynamic changes in a noninvasive manner is a unique feature of TCCS, which is therefore particularly valuable for monitoring stepwise transcatheter treatment of these lesions. Limitations of the technique, mainly caused by restrictions of the insonated bone windows, render this method inadequate as a screening tool. However, TCCS has proven to be a highly useful technique for follow-up investigations of treated and untreated cerebral aneurysms and AVMs. This chapter explains the investigation of these lesions and gives an insight into the most important up-to-date literature.