ENDOVASCULAR DOPPLER ULTRASONOGRAPHY OF I NTRACRANIAL VESSELS - TECHNICAL NOTE AND POTENTIAL APPLICATIONS

Intravascular Doppler ultrasonography was initially performed with spe cially designed catheters and was used primarily for cardiological pur poses. The recent introduction of a 0.-18-in. flexible, steerable guid e wire with an integrated 12-MHz piezoelectric transducer (FloWire) ha s made it possible to use this technique in neuroangiography. This sys tem allows recording of Doppler spectra and determination of blood flo w velocities in in tracranial vessels after subselective introduction of a standard 3-F microcatheter. The measurement of blood flow velocit y in an AVM feeding branch of a middle cerebral artery and the haemody namic effects of the vasoconstrictive substance sumatriptan on the mid dle meningeal artery are used to illustrate potential applications of intravascular Doppler ultrasonography in neuroangiography.