Journal of neuroimaging : official journal of the American Society of Neuroimaging
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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.
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Low-grade and anaplastic oligodendrogliomas are often difficult to differentiate on the basis of conventional MR imaging characteristics. Dynamic contrast-enhanced (DCE) MRI can assess tumor microvasculature and has demonstrated utility for predicting glioma grade and prognosis in primary brain tumors. The aim of our study was to evaluate the performance of plasma volume (Vp) and volume transfer coefficient (K(trans) ) derived from DCE MRI in differentiating between grade II and grade III oligodendrogliomas. ⋯ The results of our study suggest the DCE MRI parameter Vpmean can noninvasively differentiate between grade II and grade III oligodendrogliomas.
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Human entorhinal cortex (ERC) connects the temporal neocortex with hippocampus and is essential for memory retrieval and navigation. Markedly, there have been only few quantitative MRI works on the ERC geometric measurements in pediatric and adult healthy subjects across the lifespan. Here, we sought to fill this gap in knowledge by quantifying the ERC thickness in a very large cohort of subjects spanning 9 decades of life. ⋯ Our report with high spatial resolution brain MRI data from 1,660 healthy controls provided important clues about ERC thickness across lifespan. We believe that our report will pave the way for the future studies investigating distinct neural pathologies related with cognitive dysfunctions.