Three-dimensional transcranial color-coded sonography for the examination of the arteries of the circle of Willis.

Because examinations of the intracranial vessels using conventional transcranial color-coded sonography (TCCS) lack spatial orientation and reproducibility, development of a three-dimensional (3-D) imaging technique is required. Three patients with middle cerebral artery (MCA) stenosis, three with suspected intracranial aneurysm, two with vascular malformation, and one healthy volunteer were investigated by 3-D TCCS using a magnetic spatial positioning sensor mounted on the transducer for simultaneous recording of the probe coordinates to create a volumetric data set. Three-dimensional transcranial color-coded sonography enabled good visualization of intracranial aneurysms and MCA stenoses. However, it failed to detect morphological details in vascular malformations. In conclusion, 3-D TCCS is a promising technique that opens new perspectives in depicting intracranial vessels and provides volume measurement of intracranial aneurysms.