Journal of neuroimaging : official journal of the American Society of Neuroimaging
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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.
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A patient with mitochondrial encephalomyopathy, lactic acidosis, and strokelike episode (MELAS) syndrome underwent serial measurement of cerebral blood flow with xenon computed tomography (Xe-CBF) while presenting with strokelike episodes accompanied by a cerebral lesion. He underwent positron emission tomography (PET) measurement of the regional cerebral blood flow (PET-CBF), metabolic rate of oxygen (CMRO2), and glucose (CMRGlu) after his symptoms and lesion disappeared. ⋯ In the PET study, decreased CMRO2 and increased PET-CBF and CMRGlu were noted in the entire brain. The strokelike episodes of patients with MELAS are more likely attributed to the failure of oxygen metabolism than to a vascular accident.
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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 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.