Journal of neuroimaging : official journal of the American Society of Neuroimaging
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The relationship between subcortical hyperintensity (SH) on magnetic resonance imaging (MRI), cortical perfusion on single photon emission computed tomography (SPECT), and cognitive function is not well understood. The authors examined these relationships in individuals with vascular dementia (VaD), paying particular attention to frontal lobe function to determine whether the presence of SH on MRI was associated with frontal hypoperfusion on SPECT, which in turn would be associated with impairments of executive-attention function. ⋯ These results suggest that a functional "disconnection" between the frontal lobes and subcortical structures does not fully account for the magnitude of global cognitive impairment in VaD. Cortical perfusion as measured by SPECT appears to be associated with cognitive performance, but not specifically executive-attention dysfunction. Additional studies are needed to further examine the relationship between subcortical and cortical function in VaD.
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Patients with cerebellar infarction are threatened by infratentorial herniation and impaired circulation of cerebrospinal fluid if mass effect in posterior fossa develops. Clinical assessment is often impaired in patients with disturbances of consciousness. Therefore, computed tomography (CT) examination is essential in the diagnosis of complication and decision for operative treatment. ⋯ The proposed CT score is of high interrater and retest reliability, supplements the clinical assessment of the patient, and is able to monitor the efficacy of decompressive treatment.
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The authors establish accuracy parameters of a broad diagnostic battery for bedside transcranial Doppler (TCD) to detect flow changes due to internal carotid artery (ICA) stenosis or occlusion. ⋯ In symptomatic patients, bedside TCD can accurately detect flow changes consistent with hemodynamically significant ICA obstruction; however, TCD should not be a substitute for direct carotid evaluation. Because TCD is sensitive and specific for a > or = 70% carotid stenosis or occlusion in both extracranial and intracranial carotid segments, it can be used as a complementary test to refine other imaging findings and detect tandem lesions.
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Randomized Controlled Trial Multicenter Study Clinical Trial
SonoVue in transcranial Doppler investigations of the cerebral arteries.
The authors investigated the safety and diagnostic potential of a new ultrasound contrast agent (SonoVue) using transcranial color-coded duplex sonography (TCCS). ⋯ The results obtained from this multicenter study demonstrate that the administration of SonoVue to patients with ischemic cerebrovascular disease who undergo TCCS examination of cerebral vessels improves the visualization of intracranial arteries, providing a dose-dependent contrast enhancement and a clinically useful duration of signal enhancement related to the dose. During this multicenter study, SonoVue proved to be a safe and well-tolerated compound.
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Comparative Study
Transcranial Doppler pulsatility indices as a measure of diffuse small-vessel disease.
Elevation in pulsatility indices (PIs) as measured by transcranial Doppler (TCD) have been postulated to reflect downstream increased vascular resistance caused by small-vessel ischemic disease. ⋯ Elevation in PIs as measured by TCD shows strong correlation with MRI evidence of small-vessel disease. TCD may be a useful physiologic index of the presence and severity of diffuse small-vessel disease.