If the collateral vessel circulation is good, the only symptoms are those related to intracranial hypertension. First, there is an increase in retrograde venous pressure, with venous congestion and drainage through the collateral vessels. DST obstructs venous drainage, leading to increased blood pressure due to delayed venous emptying and decreased absorption of cerebrospinal fluid. Thus, two types of edema can develop: vasogenic and cytotoxic. CVT leads to the formation of an area of focal cerebral edema because of increased retrograde pressure, which is characterized by dilated veins, petechial hemorrhages that can converge and give rise to larger hematomas, and ischemic neuronal damage. In venous occlusion, changes in the brain parenchyma can develop secondary to vasogenic edema, cytotoxic edema, or intracranial hemorrhage, giving rise to two possible scenarios: CVT with local effects and CVT of the venous sinuses with increased intracranial pressure ( 1). Venous occlusion has different effects on the brain parenchyma than does arterial occlusion, resulting in different imaging findings. The objectives of this article are to (a) review the pathophysiology of CVT (b) illustrate the anatomy of the cerebral venous system (c) describe the different subtypes of CVT, including dural sinus CVT (DST), deep CVT (DCVT), and isolated cortical vein CVT (d) review the accuracy of various imaging techniques for CVT diagnosis and (e) show the main findings and pitfalls for these subtypes with different imaging techniques. Since anticoagulation is contraindicated in most cases of cerebral bleeding, diagnostic certainty is important, making the radiologist’s task more difficult. CVT is one of the few causes of cerebral hemorrhage that call for anticoagulation therapy. For this reason, imaging is crucial to diagnosis, and radiologists must be able to identify the findings that raise suspicion of CVT so that appropriate treatment (anticoagulation therapy) can be started early to avoid complications and even death. Diagnosis is difficult because the clinical manifestations of CVT are nonspecific, such as headache, seizures, decreased level of consciousness, and focal neurologic deficits. CVT can occur at any age, although it is more common in neonates and young adults (20–40 years old) it is also more common in women, because pregnancy, postpartum status, and the use of oral contraceptives increase the risk of CVT ( 1, 4, 5). The differences in incidence in the studies are likely due to differences in diagnostic techniques. The annual incidence, as presented in the most recently published studies ( 1– 3), is three or four to 13 cases per 1 million individuals. Cerebral venous thrombosis (CVT) is an uncommon condition that is potentially reversible if it is diagnosed and treated appropriately and promptly.
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