Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Resting-state functional MRI (rs-fMRI) studies in Parkinson's disease (PD) patients with freezing of gait (FOG) have implicated dysfunctional connectivity over multiple resting-state networks (RSNs). While these findings provided network-specific insights and information related to the aberrant or altered regional functional connectivity (FC), whether these alterations have any effect on topological reorganization in PD-FOG patients is incompletely understood. Understanding the higher order functional organization, which could be derived from the "hub" and the "rich-club" organization of the functional networks, could be crucial to identifying the distinct and unique pattern of the network connectivity associated with PD-FOG. ⋯ Overall, our findings demonstrate a widespread topological reorganization and disrupted higher order functional network topology in PD-FOG that may further assist in improving our understanding of functional network disturbances associated with PD-FOG.
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Volumetric and densitometric biomarkers have been proposed to better quantify cerebral edema after stroke, but their relative performance has not been rigorously evaluated. ⋯ CSF volumetric biomarkers can be automatically measured from almost all routine CTs and correlate better with standard edema endpoints than net water uptake.
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Observational Study
Evaluation of the transverse venous sinus with transcranial color-coded duplex.
Ultrasound-derived diagnosis of transverse venous sinus stenosis (TVSS) may have a promise given recent exploration of its role in pathophysiology of intracranial hypertension and availability of interventions like venous stenting. We investigated transverse venous sinus (TVS) insonation using transcranial color-coded duplex (TCCD) to establish normative values, inform on inherent physiological variability, and other measures to allow future studies on testing the construct validity of TCCD venous in diagnosing TVSS. ⋯ These results can inform future studies validating the normative values in a larger sample and help explore the role of TCCD venous in the diagnosis of venous sinus stenosis.
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Conventional MRI sequences in neuro-oncology are insufficient for glioma grading. However, newly developed diffusion-weighted imaging techniques have been shown to have a great potential for glioma grading. This study examined the diagnostic performance of diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), neurite orientation dispersion and density imaging (NODDI), and their combinations in glioma grading. ⋯ DTI, DKI, and NODDI approaches can differentiate between HGG and LGG; however, kurtosis parameters perform better and adding NODDI parameters does not improve diagnostic performance. Using multishell b-value has not led to an increase in diagnostic performance.
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Magnetic resonance imaging (MRI) plays a key role in diagnosing and monitoring multiple sclerosis (MS). Double inversion recovery (DIR) is a pulse sequence that has proven highly effective at detecting cortical lesions but is understudied in the spinal cord. We hypothesize that DIR images obtained during brain MRI can be of value in assessing the upper spinal cord of MS patients. ⋯ Sagittally acquired brain DIR can provide useful information on upper spinal cord lesions, with high C/N. In theory, this should facilitate the attainment of McDonald's or the Magnetic Resonance Imaging in MS (MAGNIMS) criteria in some cases, without a dedicated cervical spine MRI exam.