Neuroimaging clinics of North America
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The heart and the carotid arteries are the most common sites of origin of embolic disease to the brain. Clots arising from these locations are the most common types of brain emboli. Less common cerebral emboli include air, fat, calcium, infected vegetations, and tumor cells as well as emboli originating in the venous system. Although infarcts can be the final result of any type of embolism, described herein are the ancillary and sometimes unique imaging features of less common types of cerebral emboli that may allow for a specific diagnosis to be made or at least suspected in many patients.
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Neuroimaging Clin. N. Am. · Feb 2016
ReviewDetection of Vulnerable Plaque in Patients with Cryptogenic Stroke.
In up to 40% of ischemic stroke cases the etiology remains unknown. A substantial proportion of these patients has non- or only mildly stenosing carotid artery plaques not fulfilling common criteria for large artery stroke, but beeing suspicious for arterio-arteriell embolism. ⋯ Nevertheless, carotid MRI might be best suited to assess the key features of vulnerable plaques. This review article discusses potential causes of cryptogenic stroke, the role of plaque imaging in non-stenosing plaques and the association of vulnerable plaques and specific plaque features with stroke risk and stroke recurrence.
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Although treatment guidelines are well established for symptomatic patients with greater than 69% carotid stenosis on catheter angiography, optimal management of lower degrees of stenosis remain unclear. Vessel wall MR imaging of the carotid arteries has proved helpful in the evaluation of plaque burden and vulnerable plaque characteristics, and in stratifying risk in low-grade carotid stenosis. This article discusses the pathophysiology and imaging of atherosclerotic plaques resulting in low-grade carotid stenosis, and the corresponding stroke risk and association with plaque elsewhere in the cardiovascular system.
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Neuroimaging Clin. N. Am. · Feb 2016
Review Meta AnalysisClinical Perspective of Carotid Plaque Imaging.
At present, patients with carotid disease are selected for invasive recanalization therapies mainly based on the degree of luminal narrowing and the presence or absence of recent ischemic symptoms. A more sophisticated risk model takes into account other clinical variables, such as age, sex, and the type of recent symptoms, as well as presence of ulcerated plaque. A growing body of evidence shows that noninvasive imaging of the carotid plaque by various methods reliably identifies structural correlates of plaque vulnerability, which are associated with an increased risk of cerebrovascular events.