Clinical utility of echocontrast agents in neurosonology.
INTRODUCTION: Neurosonological investigations of the extracranial and intracranial brain supplying arteries are helpful in the assessment of stroke and stroke-prone patients. METHODS: In this paper we review the indications, application and advantages of second-generation (gas-filled) microbubble contrast agents such as SonoVue. RESULTS: Gas-filled microbubbles have a strong echo enhancing effect and produce enhancement for several minutes, enabling the sonographer to perform the investigation with a single injection or two or three repeated injections without the need for continuous administration. Echocontrast agents provide better delineation of normal blood flow, occlusions, pseudo-occlusions, stenoses, and collaterals in the extracranial and intracranial vascular beds. They are of particular value during transcranial color-coded transcranial duplex investigations via the temporal and occipital window. CONCLUSIONS: Echocontrast agents give additional information on the patient's vascular situation that is often crucial to planning further diagnostic and therapeutic steps. The use of second-generation gas-filled microbubbles, such as SonoVue in transcranial neurosonology, may help to avoid unnecessary, expensive and potentially harmful additional investigations such as intra-arterial DSA. Future applications include the visualization of brain tissue perfusion.