Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Intracranial pressure (ICP) can be monitored by the optic nerve sheath diameter (ONSD) technique. We hypothesized that diameter of the optic canal (OC) can be a limiting factor for this technique. ⋯ In its narrowest part, the average OC is 11 to 16.75 mm² wide. We suggest measuring this area simultaneously with the ONSD during ICP monitoring. If the area of the narrowest lumen of the canal is less than 10 mm², ONSD technique for ICP monitoring should not be used.
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Contrast-enhancing lesions (CEL) on magnetic resonance imaging (MRI) are believed to represent inflammatory disease activity in multiple sclerosis (MS), but their relationship to subsequent long-term disability and progression is unclear, particularly at longer time periods such as 8-10 years. ⋯ While number and volume of CEL at baseline do not directly correlate with disability in the longer term in MS, our data suggest that 1 route to disability involves relapses as a mediator variable in the causal sequence of MS progression from CEL to disability. Further studies using relapse as a mediator variable in a larger data set may be warranted.
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The transcranial sonography (TCS) finding of reduced echogenicity of brainstem raphe (hypoechogenic BR) has been associated with depressive states. Here, we review the TCS studies in subjects with depressive disorders and with depression related to degenerative brain diseases, and compare the frequency and clinical correlates of hypoechogenic BR in these reports. Summarizing the data published so far, hypoechogenic BR is present in 67% (range, 37-95%) of depressed but only in 15% (5-36%) of nondepressed subjects without history of neurodegenerative disease. ⋯ Although some studies did not show any relationship between BR echogenicity and severity of depression, others suggest an association with higher severity of depression, or even with suicidal ideation. In one study BR hypoechogenicity was found to be associated with better responsivity to serotonin reuptake inhibitors. Further studies are warranted to compare the TCS findings of BR alteration with post-mortem histopathological findings, and with genetic variants related to cerebral serotonin metabolism.
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To determine the feasibility of apparent diffusion coefficient (ADC)-based thermometry to assess intraventricular temperature in children. ⋯ ADC-based thermometry has limited application in the pediatric population mainly due to a small ventricular size.
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This study was designed to evaluate the potential of the dynamic autoregulation index (ARI) to serve as an early warning system for an imminent clinical deterioration after subarachnoid hemorrhage (SAH). ⋯ The results demonstrate the capability of the ARI to serve as a reliable early warning system after SAH. Further trials with larger study populations are needed to validate these promising preliminary data.