No abstract

The aim of this review is to describe the acquisition and reformatting of state of the art high resolution cone beam CT (HR-CBCT) and demonstrate its role in multiple neurovascular conditions as a tool to improve the understanding of disease and guide therapeutic decisions. First, we will review the basic principle of CBCT acquisition, followed by the injection protocols and the reformatting paradigms. Next, multiple applications in different pathological conditions such as aneurysms, arteriovenous malformations, dural arteriovenous fistulas, and stroke will be described. HR-CBCT angiography, widely available, is uniquely useful in certain clinical scenarios to improve the understanding of disease and guide therapeutic decisions. It rapidly is becoming an essential tool for the contemporary neurointerventionalist.AChoAho

Meaningful contributions to neurointerventional practice may be possible by considering the dynamic aspects of angiography in addition to fixed morphologic information. The functional approach to venous anatomy requires integration of the traditional static anatomic features of the system—deep, superficial, posterior fossa, medullary veins, venous sinuses, and outflow routes into an overall appreciation of how a classic model of drainage is altered, embryologically, or pathologically, depending on patterns of flow—visualization made possible by angiography. In this review, emphasis is placed on balance between alternative venous networks and their redundancy, and the problems which arise when these systems are lacking. The role of veins in major neurovascular diseases, such as dural arteriovenous fistulae, arteriovenous malformations, pulsatile tinnitus, and intracranial hypertension, is highlighted, and deficiencies in knowledge emphasized.

BACKGROUND The role of arteriovenous shunts such as dural fistulas, arterial steno‐occlusive states, anatomic variants, and hypervascular tumors in the genesis of pulsatile tinnitus (PT) has long been recognized. On the venous side, diverticula, high‐riding jugular bulb, and sinus wall dehiscence have also been implicated. However, the overall most common cause—venous sinus stenosis (VSS)—continues to be underrecognized. Its clinical importance, separate from venous stenosis association with intracranial hypertension, also requires emphasis. METHODS A retrospective review of the last consecutive 208 cases of PT seen at our institution was performed and cause determined, when possible, based on clinical and radiographic data. RESULTS VSS was the common cause of PT (34% of overall cohort). Over 90% are women. Typical clinical presentation was a unilateral whoosh‐like sound in sync with heartbeat that could be completely or nearly completely abolished by ipsilateral jugular compression. This clinical scenario virtually guaranteed the presence of VSS, with very high sensitivity, specificity, positive, and negative predictive values. About two thirds of patients with VSS also harbored other venous anatomic variations such as a high‐riding jugular bulb or sinus diverticulum, that should not be misinterpreted as the primary cause of PT. Most did not have signs or symptoms of intracranial hypertension, even though cerebrospinal fluid and venous pressures are frequently elevated. CONCLUSIONS VSS appears to be the most common identifiable cause of PT. Judicious attention to this finding can be immensely helpful in prompt and accurate diagnosis.