(a) Review the clinical presentation, classification and imaging findings of dural arteriovenous fistulas (DAVFs); (b) Summarize and illustrate ultrasonographic suggestive features of DAVFs; (c) Highlight the current progress regarding carotid ultrasonography in the evaluation of DAVFs. Please note that DAVFs in the cavernous sinus (Carotid-cavernous fistulas Barrow type B–D) are out of the scope of the present work, due to the extremely limited value ofcarotid ultrasonography in those lesions.

1) Introduction Intracranial dural arteriovenous fistulas (DAVFs) are pathologic shunts between dural arteries and dural venous sinuses, meningeal veins or cortical veins. Their true incidence is unknown, but they are estimated to account for 10%–15% of all intracranial arteriovenous malformations (AVMs), comprising arround 6% of supratentorial and 35% of infratentorial AVMs. DAVFs tend to present later in life than AVMs and are distinguished from parenchymal or pial AVMs mostly by the presence of a dural arterial supply and the absence of a parenchymal nidus. Althouth...

Carotid doppler sonography (CDS) represents a minimally invasive screening test that yield hemodynamic information very suggestive of DAVF, such as low resistance and high velocity flow in external carotid arteries (ECA). These hemodynamic changes can be useful for follow-up and evaluation of treatment effectiveness. On the other hand, the most important limitation is that it only shows the hemodynamic changes in the feeding arteries without showing the actual size and patterns of the venous drainage. As CDS has been widely used to evaluate the severity...

DAVFs natural history is complex and they may present in a variety of ways. CTA and MRA can provide useful information for diagnosis, classification and treatment planning, butdigital subtraction angiography remains the gold-standard study. Early screening of DAVF may prevent aggressive manifestations, especially in mild symptomatic patients. CDS can play a role as an initial screening and follow-up tool, considering the convenience, noninvasiveness, low cost and reproducibility of its results.

João Pedro Filipe1, Tiago Parreira1, Carlos Andrade2,3, Rosa Santos4, Elsa Azevedo2,3,4 1Department of Neuroradiology, Hospital de São João, Porto, Portugal; 2Department of Neurology, Hospital de São João, Porto, Portugal; 3Faculty of Medicine, Porto University, Porto, Portugal; 4Neurosonology Unit, Department of Neurology, Hospital de São João, Porto, Portugal;

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