Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Three-dimensional cinematic rendering (3DCR) is an emerging postprocessing technique for computed tomography (CT) and CT angiography (CTA) that produces photorealistic, volumetric images. In contrast to conventional volume rendering techniques, 3DCR depicts life-like shadowing and surface reflection, which can improve the perception of depth and complex anatomic spatial relationships. This tool allows clinical neuroimagers to study, explore, and teach the complex relational anatomy of the cerebral vessels and skull in a more intuitive manner. ⋯ Next, we discuss surface rendering as a means of recapitulating the neurologic physical exam. Last, we provide a step-by-step method of simulating the operating room perspective in visualizing cerebrovascular disease. In our experience, 3DCR proves most useful for visualizing structures at the vessel-skull interface, which can be difficult to assess with conventional imaging methods. 3DCR, therefore, complements traditional 2-dimensional and 3-dimensional imaging methods and serves as an emerging tool for neuroimagers to communicate with and educate other clinicians.
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Cerebral blood flow (CBF) has been reported to increase after shunt surgery in patients with idiopathic normal pressure hydrocephalus (iNPH). The aims of this study were to investigate if CBF, measured using the noninvasive perfusion MRI method arterial spin labeling (ASL), increased after shunt surgery, if postoperative change in CBF correlated with improvement in symptoms, and if baseline CBF data correlated with postoperative outcome. ⋯ The clinical value of ASL in the work-up of patients with iNPH is uncertain. In this study, ASL could not predict outcome after shunt surgery and there were no correlations between change in CBF and change in clinical symptoms after shunt surgery.
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Meta Analysis
Quantification of Optic Nerve and Sheath Diameter by Transorbital Sonography: A Systematic Review and Metanalysis.
To date, normal values for optic nerve diameter (OND) and optic nerve sheath diameter (ONSD) for transorbital sonography (TOS) have only been reported by individual small-scale studies, exposing a great variability in the measurement of the OND and ONSD. ⋯ TOS is a frequently described and widely used method. We provide reference values of OND and ONSD that are based on metanalytical analysis. Different measuring methods of ONSD result in higher heterogeneity. Subgroup analysis revealed no significant correlation between ONSD and age, gender, or geographic origin.
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Neuroimaging plays a critical role in the management of patients with gliomas. While conventional magnetic resonance imaging (MRI) remains the standard imaging modality, it is frequently insufficient to inform clinical decision-making. There is a need for noninvasive strategies for reliably distinguishing low-grade from high-grade gliomas, identifying important molecular features of glioma, choosing an appropriate target for biopsy, delineating target area for surgery or radiosurgery, and distinguishing tumor progression (TP) from pseudoprogression (PsP). ⋯ Positron emission tomography is useful for measuring tumor metabolism, which correlates with grade and can distinguish TP/PsP in the right setting. Magnetic resonance spectroscopy can identify tissue by its chemical composition, can distinguish TP/PsP, and can identify molecular features like 2-hydroxyglutarate. Finally, amide proton transfer imaging measures intracellular protein content, which can be used to identify tumor grade/progression and distinguish TP/PsP.