Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Identification of significant asymptomatic carotid artery stenosis (ACAS) is important because of the stroke-risk reduction observed with carotid endarterectomy. The authors developed and validated a simple scoring system based on routinely available information to identify persons at high risk for ACAS using data collected during a community health screening program at various sites in western New York. A total of 1331 unselected volunteers without previous stroke, transient ischemic attack, or carotid artery surgery were evaluated by personal interview and duplex ultrasound. ⋯ The scheme effectively stratified the validation set (n = 444); the likelihood ratio and posttest probability for ACAS in the high-risk group were 3.0 and 35%, respectively, and in the intermediate and low-risk groups were 1.4 and 20% and 0.4 and 7%, respectively. Routinely available information can be used to identify persons in the community at high risk for ACAS. Doppler ultrasound screening in this subgroup may prove to be cost-effective and have an effect on stroke-free survival.
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Although anterior circulation transient ischemic attacks (TIAs) tend to be more common in patients with extra- cranial carotid arterial disease than in those with intracranial carotid or middle cerebral arterial disease, the authors recently encountered 4 patients with both recurrent, stereotypical TIAs as well as isolated stenosis of their petrous internal carotid artery (ICA). While the gold standard for establishing the diagnosis of intracranial large-artery disease has always been conventional angiography, magnetic resonance angiography changes, confirmed with intra-arterial digital subtraction angiography in 2 of these patients, were quite sufficient to define the occlusive disease in each of the cases. Petrous ICA stenosis is not uncommon, but it has often been overshadowed by the search for extracranial ICA disease that might be amenable to surgical reconstruction.
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Intravenous recombinant tissue plasminogen activator (rt-PA) is the only therapy of proven value for patients with acute ischemic stroke (AIS). Controversy exists with regard to the prognostic significance of early computed tomography (CT) changes in patients receiving rt-PA for AIS. The authors retrospectively reviewed all cases of AIS who received intravenous rt-PA for AIS in University of South Alabama hospitals between January 1996 and May 1999. ⋯ The frequency of specific findings were as follows: SE in 13 patients (36%), LGWD in 12 patients (33%), PH in 9 patients (25%), HMCA in 4 patients (11%), and IRS in 3 patients (8%) patients. There was no statistically significant association between the occurrence of these imaging findings and subsequent functional outcome after thrombolysis. The data suggest that the presence of subtle acute CT changes in AIS patients is not predictive of clinical outcome following administration of rt-PA as per National Institute of Neurological Disorders and Stroke protocol.
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Case Reports
Transcranial color-coded sonography of a vein of Galen arteriovenous malformation in an adult.
The case of an adult harboring a vein of Galen arteriovenous malformation (VGAM) is reported. Diagnosis was established by computed tomography (CT) and digital subtraction angiography and confirmed afterwards by transcranial color-coded sonography (TCCS). ⋯ The results of TCCS were validated by angiography, with which they showed good correlation. Thus, it can be concluded that TCCS may be a useful adjunct to CT and angiography to noninvasively monitor adults with VGAM.
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Brain atrophy may occur early in the course of multiple sclerosis (MS) and may be associated with disability. Brain magnetic resonance imaging (MRI) of 114 MS patients (group A) were analyzed for regional atrophy (vs age-/gender-matched controls) and T1 and T2 lesions using 4-point rating systems. Thirty-five separate patients (group B) were analyzed for cortical atrophy (ordinal scale), third ventricular width, and total T2 hyperintense lesion volume (computer assisted). ⋯ Mean kappa coefficients of ordinal ratings were 0.9 (intraobserver) and 0.8 (interobserver). Ordinal ratings correlated well with quantitative assessments. The authors conclude that brain atrophy is closely associated with physical disability and clinical course in MS patients and can be appreciated using a semiquantitative MRI regional rating system.