Three-Dimensional Transcranial Color-Coded Sonography of Cerebral Aneurysms

<jats:p> <jats:italic>Background and Purpose</jats:italic> —The role of 2-dimensional transcranial color-coded sonography (2D-TCCS) as a diagnostic tool in cases of vascular alteration is unquestioned. The skill of the operator, however, may be responsible for some intertrial variability. The clinical value of a new, workstation-based, 3D reconstruction system for TCCS was evaluated in patients with intracranial aneurysms. </jats:p> <jats:p> <jats:italic>Methods</jats:italic> —Thirty patients with 30 intracranial aneurysms were investigated (8 men, 22 women; mean±SD age 54±17 years). The TCCS examinations were performed with a 2-MHz probe using the power mode. The 3D system (3D-Echotech, Germany) consisted of an electromagnet, which induced a low-intensity magnetic field near the head of the patient. A magnetic position sensor was attached to the ultrasound probe and transmitted the spatial orientation of the probe to a workstation, which also received the corresponding 2D-images from the video-port of the duplex machine. The echo contrast enhancer <jats:sc>d</jats:sc> -galactose (Levovist, Schering, Germany) was used in all patients to improve the signal-to-noise ratio. All patients underwent presurgical digital subtraction angiography (DSA) to demonstrate the aneurysm. </jats:p> <jats:p> <jats:italic>Results</jats:italic> —Twenty-nine of 30 angiographically proven intracranial aneurysms (97%) were detected by 3D-TCCS. The aneurysmal diameter estimated by DSA ranged from 3 to 16 mm (mean 7.2±3.6 mm). A comparison of the 3 main diameters of each aneurysm revealed a correlation coefficient of 0.95 between DSA and 3D-TCCS. The 3D determination of the aneurysmal size by 2 experienced sonographers correlated with 0.96. </jats:p> <jats:p> <jats:italic>Conclusions</jats:italic> —3D-TCCS is a new, noninvasive method to investigate intracranial aneurysms. The differentiation between artifacts and true changes of the vessel anatomy is much easier in 3D-TCCS than in conventional 2D-TCCS. The new method yields an excellent correlation with the gold standard, DSA. Because the same 3D-TCCS data can be postprocessed by different investigators, it may be possible to improve reproducibility and increase the objectivity of transcranial color-coded duplex sonography. </jats:p>