Journal of neuroimaging : official journal of the American Society of Neuroimaging
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In patients with symptomatic vertebrobasilar intracranial atherosclerotic disease (ICAD), impaired distal flow predicts recurrent stroke, but limited data exist on the association between perfusion status and recurrent stroke in anterior circulation ICAD. ⋯ Distal hypoperfusion in acutely symptomatic ICAD with 50-99% stenosis is associated with stroke recurrence. Distal hypoperfusion could be used to enrich future trials of secondary stroke prevention in ICAD patients.
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Spinal cord injury (SCI) leads to a general lack of sensory and motor functions below the level of injury and may promote deafferentation-induced brain reorganization. Functional magnetic resonance imaging (fMRI) has been established as an essential tool in neuroscience research and can precisely map the spatiotemporal distribution of brain activity. Task-based fMRI experiments associated with the tongue, upper limbs, or lower limbs have been used as the primary paradigms to study brain reorganization following SCI. ⋯ In articles that show alterations, there is no agreement if they are transient or permanent. Besides, there is no consensus on which areas are most prone to activation changes, or on the intensity and direction (increase vs. decrease) of those possible changes. In this article, we present a critical review of the literature and trace possible reasons for those contradictory findings on brain reorganization following SCI. fMRI studies based on the ankle dorsiflexion, upper-limb, and tongue paradigms are used as case studies for the analyses.
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The changing MRI signal accompanying brain maturation in fetal brains can be quantified on apparent diffusion coefficient (ADC) maps. Deviations from the natural course of ADC values may reflect structural pathology. The purpose of this study was to determine the influence of fetal pathologies on the ADC values in different regions of the fetal brain and their evolution with increasing gestational age. ⋯ The ADC values in different regions of the fetal brain and their evolution with increasing gestational age are influenced by pathologies compromising the cerebral maturation.
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Ischemic stroke can occur in 20-55% of patients with infective endocarditis (IE) with 75% occurring during the first 2 weeks of treatment. CT or MRI brain can diagnose the sequelae of stroke but transcranial Doppler (TCD) can document active embolization. We undertook a retrospective review of our patient cohort and a systematic review of literature to assess the role of TCD in early diagnosis and management of ischemic stroke in IE. ⋯ Presence of embolization in the form of high-intensity transient signals (HITS) detected on TCDs can be used for early diagnosis of IE, assessing efficacy of antibiotic therapy, and stratification of stroke risk in IE. This can aid further research into testing preventative interventions for reducing stroke burden in IE such as earlier valvular surgery or vacuum-assisted vegetation extraction.
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This study aims to investigate whether radiomic quantitative image features (IFs) from perfusion dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) retain sufficient strength to predict O6-methylguanine-DNA methyltransferase promoter methylation (MGMT_pm) in newly diagnosed glioblastoma (GB) patients. ⋯ rIFs from perfusion DSC-MRI are potential biomarkers in GBs with a ≥30% MGMT_pm. Otherwise, unmethylated and intermediate-methylated GBs lack of rIFs. Five of 14 rIFs show sufficient strength to build an accurate prediction model of MGMT_pm.