Acute Cerebral Venous Thrombosis

Cerebral venous thrombosis (CVT) affects particularly young adults with an incidence of 1.3 per 100 000 personyears in the general population and is more frequent in young women. Diagnosis and treatment of CVT is challenging as clinical signs and symptoms (eg, headache, impaired vision, focal deficit, and seizures) are unspecific. CVT can be complicated by brain infarction and intracranial hemorrhage, and cerebral herniation is the most frequent cause of death. If untreated, CVT develops an unfavorable course in 15% with a mortality rate approximating 10%. Thrombosis of the deep cerebral veins, for example, is associated with even worse outcome. Over the past decades, mortality has declined because of improved diagnostics resulting in earlier treatment using anticoagulation. Prognostic factors in CVT rely on various symptoms (eg, disturbed consciousness and seizures) and clinical parameters (eg, cerebral hemorrhage and straight sinus thrombosis). However, little is known about venous hemodynamics in acute CVT, their change during disease, and their impact on prognosis. Routine computed tomographic imaging and magnetic resonance imaging (MRI) lack quantitative hemodynamic information. Conventional digital subtraction angiography provides such data to a certain extent but is invasive and carries the risk of complications and is not recommended for routine imaging. Thus, most data on intracranial venous hemodynamics was derived from transcranial duplex sonography, which requires highly experienced examiners and is restricted to vessel segments assessable through a limited acoustic bone window. By contrast, 4-dimensional (4D) flow MRI has the potential to examine the entire cerebral venous system and thus visualize and quantify hemodynamics in vivo. In this study, we aimed to demonstrate 4D flow MRI in patients with acute CVT. We sought to comprehensively Background and Purpose—Cerebral venous thrombosis (CVT) affects venous hemodynamics and can provoke severe stroke and chronic intracranial hypertension. We sought to comprehensively analyze 3-dimensional blood flow and hemodynamic alterations during acute CVT including collateral recruitment and at follow-up. Methods—Twenty-two consecutive patients with acute CVT were prospectively included and underwent routine brain magnetic resonance imaging (MRI) and 4-dimensional flow MRI at 3 T for the in vivo assessment of cerebral blood flow. Neurological and MRI follow-up at 6 months was performed in 18 patients. Results—Three-dimensional blood flow visualization and quantification of large dural venous sinuses and deep cerebral veins was successfully performed in all patients. During acute CVT, we observed abnormal flow patterns including stagnant flow, flow acceleration in stenoses, and change of flow directions. In patients with complete recanalization, flow trajectories resembled those known from previously published 4-dimensional flow MRI data in healthy adults. There was a trend toward a relationship between occluded segments and cerebral lesions (not significant). Furthermore, patients with versus without cerebral lesions showed increased mean (0.08±0.09 versus 0.005±0.014 m/s) and peak velocities (0.18±0.21 versus 0.006±0.02 m/s) within partially thrombosed left and right transverse sinuses (P<0.05) at baseline. Conclusions—Four-dimensional flow MRI was successfully applied for the 3-dimensional visualization and quantification of venous hemodynamics in patients with CVT and provided new dynamic information regarding vessel recanalization. This technique seems promising to investigate the contribution of hemodynamic parameters and collaterals in a larger cohort to identify those at risk of stroke. (Stroke. 2017;48:671-677. DOI: 10.1161/STROKEAHA.116.015102.)