[Simultaneous use of ultrasound and pulsed Doppler with spectrum analysis of frequency in diseases of the cervical and cerebral vessels. Initial results].

Preliminary results of the use of the ultrasound Duplex Scanner are reported and correlated with angiographic findings. The main interest of this examination resides in its application in cases of atheromatous obstruction of cervical vessels to the brain: definition of type of obstruction: occlusion or stenosis; assessment of hemodynamic alterations: modification of frequency spectrum, of pulsed Doppler signal to 5 degrees as defined by Strandness as a function of extent of narrowing of arterial lumen. Pre-occlusive lesions may be difficult to distinguish from an occlusion. In contrast, minor anomalies: plaque producing little or no stenosis, calcifications, appear to be simpler to detect than by angiography. In intracranial vascular malformations: arteriovenous fistulas and particularly intracranial angiomas of a certain size, this examination provides data on the increase in diameter and acceleration of flow in vessels supplying the malformation. In cases of brain death, the ultrasound Duplex Scanner demonstrates absence or marked reduction in internal carotid artery flow, whereas flow is normal in the external carotid arteries in the absence of collapse. Confirmation of reliability of this non-invasive exploratory procedure requires further evidence of correlations.