Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Multiple sclerosis-related cognitive impairment (MSrCI) affects most patients with multiple sclerosis (MS), significantly contributing to disability and socioeconomic challenges. MSrCI manifests across all disease stages, mainly impacting working memory, information processing, and attention. To date, the underlying mechanisms of MSrCI remain unclear, with its pathogenesis considered multifactorial. ⋯ Key findings ifrom rs-fMRI studies reveal disruptions in brain connectivity and hub integration, leading to CI due to decreased network efficiency. tb-fMRI studies highlight abnormal brain activation patterns in pwMS, with evidence of increased fMRI activity in earlier disease stages as a beneficial compensatory response, followed by reduced activation correlating with increased lesion burden and cognitive decline as the disease progresses. This suggests a gradual exhaustion of compensatory mechanisms over time. These findings support fMRI not only as a diagnostic tool for MSrCI but also as a potential imaging biomarker to improve our understanding of disease progression.
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Ancillary testing is essential for diagnosing brain death/death by neurologic criteria (BD/DNC) when clinical determination (neurologic exam and apnea testing) cannot be fully or safely performed. Transcranial Doppler ultrasound (TCD) has been recommended as an ancillary test; however, the technical descriptions have been heterogeneous. We aimed to consolidate the technical considerations related to the use of TCD as an ancillary test in the evaluation of BD/DNC. ⋯ We found significant inconsistencies and a lack of technical details described in the literature. Next steps include a national survey of current TCD protocols for BD/DNC evaluation, and an expert consensus guidelines report on the technical use of TCD as an ancillary test.
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Despite multimodal treatment of glioblastoma (GBM), recurrence beyond the initial tumor volume is inevitable. Moreover, conventional MRI has shortcomings that hinder the early detection of occult white matter tract infiltration by tumor, but diffusion tensor imaging (DTI) is a sensitive probe for assessing microstructural changes, facilitating the identification of progression before standard imaging. This sensitivity makes DTI a valuable tool for predicting recurrence. A systematic review was therefore conducted to investigate how DTI, in comparison to conventional MRI, can be used for predicting GBM progression. ⋯ These findings suggest that DTI metrics may be useful for guiding surgical and radiotherapy planning for GBM patients, and for informing long-term surveillance. Understanding the current state of the literature pertaining to these metrics' trends is crucial, particularly as DTI is increasingly used as a treatment-guiding imaging modality.
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Differentiation between functioning and nonfunctioning pituitary adenomas/pituitary neuroendocrine tumors (PAs) is clinically relevant. The goal of this study was to determine the feasibility of using time-dependent diffusion MRI (dMRI) for microstructural characterization of PAs. ⋯ The cADC derived from time-dependent dMRI could distinguish between functioning and nonfunctioning PAs, particularly those producing GH.
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Structural MRI (sMRI) is used in monitoring multiple sclerosis (MS) but lacks sensitivity in detecting clinically relevant damage to normal-appearing white matter (NAWM), that is, pre-lesional tissue, and specificity for identifying the underlying substrate of injury. In this longitudinal study, we identified pre-lesional tissue in MS patients and investigated its microstructure by modeling diffusion-weighted imaging (DWI) data using diffusion tensor imaging and neurite orientation dispersion and density imaging (NODDI). ⋯ DWI and, more particularly, NODDI, can reveal the unique microstructure of persistent, resolved, and pre-lesional tissue in MS.