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S troke ranks as the third leading cause of death in the United States. It is now estimated that there are more than 700 000 incident strokes annually and 4.4 million stroke survivors. 1,2 The economic burden of stroke was estimated by the American Heart Association to be $51 billion (direct and indirect costs) in 1999. 3 Despite the advent of treatment of(More)
The size of intracranial aneurysms is the only characteristic shown to correlate with their rupture. However, the critical size for rupture has varied considerably among previous accounts and remains a point of controversy. Our goal was to identify statistically significant clinical and morphological factors predictive of the occurrence of rupture and(More)
MEDLINE searches identified epidemiologic, experimental, and clinical studies on the genetics of cerebrovascular disease and stroke, including the following topics: genetic epidemiology of stroke; genetics of systemic disorders that cause ischemic stroke, including coagulation disorders, connective tissue disorders, vasculopathies, metabolic disorders, and(More)
The imaging of scattered photons degrades contrast and is a major source of error in the quantitation of activity. It was hypothesized that, if the photopeak was divided into two nonoverlapping energy windows, a regression relation could be obtained between the ratio of counts within these windows and the scatter fraction for counts within the total region.(More)
Despite widespread applications in biomedical research, the role of models and modeling is often controversial and ill understood. It is usual to find that fundamental definitions, axioms, and postulates used in the modeling process have become tacit assumptions. What is essential, however, is a clear vision of the fundamental principles of modeling. This(More)
Hemodynamics play a significant role in the propensity of intracranial arteriovenous malformations (AVMs) to hemorrhage and in influencing both therapeutic strategies and their complications. AVM hemodynamics are difficult to quantitate, particularly within or in close proximity to the nidus. Biomathematical models represent a theoretical method of(More)
OBJECTIVES To survey US physicians involved in acute stroke care to determine the proportion of hospitals that currently meet the recommended Brain Attack Coalition (BAC) criteria for Primary Stroke Centers (PSC) and obtain opinions regarding the value of stroke centers. METHODS A survey regarding the BAC guidelines for the establishment of stroke centers(More)
BACKGROUND AND PURPOSE Nidus rupture is a serious complication of intracranial arteriovenous malformation (AVM) embolotherapy, but its pathogenetic mechanisms are not well described. An AVM model based on electrical network analysis was used to investigate theoretically the potential role of hemodynamic perturbations for elevating the risk of nidus vessel(More)
The propensity of intracranial arteriovenous malformations (AVMs) to hemorrhage is correlated significantly with their hemodynamic features. Biomathematical models offer a theoretical approach to analyse complex AVM hemodynamics, which otherwise are difficult to quantify, particularly within or in close proximity to the nidus. Our purpose was to investigate(More)
Mathematical models of aneurysms are typically based on Laplace's law which defines a linear relation between the circumferential tension and the radius. However, since the aneurysm wall is viscoelastic, a nonlinear model was developed to characterize the development and rupture of intracranial spherical aneurysms within an arterial bifurcation and(More)