Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Neonates presenting with neurologic symptoms require rapid, noninvasive imaging with high spatial resolution and tissue contrast. Magnetic resonance imaging (MRI) is currently the most sensitive and specific imaging modality for evaluation of neurological pathology. This modality does come with several challenges in the neonatal population, namely, the need to transport a possibly critically sick neonate to the MRI suite and the necessity of the neonate to remain still for a significant length of time, occasionally requiring sedation. ⋯ The major drawback of cranial ultrasound is its lower sensitivity and specificity for subtle/early lesions. Contrast-enhanced ultrasound (CEUS) and elastography have the potential to improve sensitivity and specificity for a variety of neuropathology but also expand the indications for cranial ultrasound. Goal of this paper is to present and discuss CEUS and elastography for neonatal brain imaging.
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Treatment of complex aneurysms using microsurgical and other conventional neuroendovascular techniques remains challenging. As a result, stent- and balloon-assisted coiling are instead performed to treat morphologically complex aneurysms, which include giant, wide-necked, and fusiform aneurysms. While these techniques have had success in treating these complex aneurysms, recanalization rates associated with these techniques are still problematic. ⋯ Subsequent to the diverting away of blood from the aneurysm, a thrombotic cascade ensues that ultimately results in the closure of the aneurysm while the parent vessel's perforators are preserved. Current known risks for this procedure include vessel rupture or perforation, in-stent thrombosis, perforator occlusion, procedural or delayed hemorrhages, and perianeurysmal edema. In this review, we will evaluate the mechanisms of actions, clinical applications, complications, and ongoing studies for FDSs.
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Review
Wallerian Degeneration Beyond the Corticospinal Tracts: Conventional and Advanced MRI Findings.
Wallerian degeneration (WD) is defined as progressive anterograde disintegration of axons and accompanying demyelination after an injury to the proximal axon or cell body. Since the 1980s and 1990s, conventional magnetic resonance imaging (MRI) sequences have been shown to be sensitive to changes of WD in the subacute to chronic phases. More recently, advanced MRI techniques, such as diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI), have demonstrated some of earliest changes attributed to acute WD, typically on the order of days. ⋯ This article reviews the utility of conventional and advanced MRI techniques for assessing WD, by focusing not only on the corticospinal tract but also other neural tracts less commonly thought of, including corticopontocerebellar tract, dentate-rubro-olivary pathway, posterior column of the spinal cord, corpus callosum, limbic circuit, and optic pathway. The basic anatomy of these neural pathways will be discussed, followed by a comprehensive review of existing literature supported by instructive clinical examples. The goal of this review is for readers to become more familiar with both conventional and advanced MRI findings of WD involving important neural pathways, as well as to illustrate increasing utility of advanced MRI techniques in providing important prognostic information for various pathologies.
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Major Axis-I disorders including major depressive disorder (MDD), bipolar disorder (BD), anxiety disorder, and schizophrenia are associated with a host of aberrations in the way social stimuli are processed. Face perception tasks are often used in neuroimaging research of emotion processing in both healthy and patient populations, and to date, there exists a mounting body of evidence, both behavioral and within the brain, indicating that emotional faces compared to neutral faces are processed abnormally by those with Axis-I disorders relative to healthy control (HC) groups. The use of neutral faces as a "baseline control condition" is predicated on the assumption that neutral faces are processed in the same way HCs and individuals with major Axis-I disorders. ⋯ Specifically, increased amygdala activation was consistently reported in response to neutral faces in anxiety disorders and schizophrenia. Abnormal medial PFC activity was reported in patients with MDD, and patients with BD exhibit decreased activity in the DLPFC and ACC relative to HCs. In addition, specific suggestions to overcome these obstacles with new research and additional analyses are discussed.
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Genetic skeletal disorders (GSDs) are a heterogeneous group characterized by an intrinsic abnormality in growth and (re-)modeling of cartilage and bone. A large subgroup of GSDs has additional involvement of other structures/organs beside the skeleton, such as the central nervous system (CNS). CNS abnormalities have an important role in long-term prognosis of children with GSDs and should consequently not be missed. ⋯ A wide spectrum of morphological abnormalities is associated with GSDs. Early diagnosis of CNS involvement is important in the management of children with GSDs. This pattern-recognition approach aims to assist and guide physicians in the diagnostic work-up of CNS involvement in children with GSDs and their management.