LATERAL CRANIAL DURAL FISTULA - DETECTION BY DOPPLER AND DUPLEX SONOGRAPHY

Cranial dural fistulae are rare; when they occur, it is usually diffic ult to detect them at an early stage, With a view to the question of p ossible progress in diagnosis we now report on seven patients with lat eral dural fistulae fed by branches of the external carotid artery. Th e examination was carried out before selective arteriography using cw- Doppler sonography and colour coded duplex sonography in combination, Sonographic criteria for detection of hyperperfusion take account of f low velocity as well as pulsatility. In all cases hyperperfusion of th e external carotid artery and the common carotid artery was detected. In most of these cases pathologic findings were also observed at the o ccipital artery, and more rarely in the contralateral external carotid artery or the ipsilateral vertebral artery, in addition, A possible s ource of error arising from confusion of blood vessels was present wit h the cw-Doppler sonography, but not for colour coded duplex sonograph y. Therefore, cranial dural fistulae characterized by a high shunt vol ume can be diagnosed correctly by indirect Doppler sonographic criteri a using cw-Doppler and duplex sonography. Direct visualization of the fistula and its nidus requires additional selective arteriography, in the course of which endovascular embolization may be performed.