Journal of neuroimaging : official journal of the American Society of Neuroimaging
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The venous outflow profile (VOP) is a crucial yet often overlooked aspect affecting stroke outcomes. It plays a major role in the physiopathology of acute cerebral ischemia, as it accounts for both the upstream arterial collaterals and cerebral microperfusion. This enables it to circumvent the limitations of various arterial collateral evaluation systems, which often fail to consider impaired autoregulation and its impact on cerebral blood flow at the microcirculatory levels. In this narrative review, we will highlight the different parameters and modalities used to assess the VOP in acute ischemia. ⋯ VOP parameters' significance lies in their potential to predict tissue fate and, subsequently, clinical outcomes. Recent studies indicate that favorable VOP is independently associated with slower rates of infarct edema progression, smaller infarct volumes, and higher rates of functional independence after 90 days. Moreover, it is considered a predictor of recanalization success and the first-pass effect during mechanical thrombectomy. Conversely, an unfavorable VOP predicts futile recanalization and indicates a higher risk of reperfusion hemorrhage. Our aim is to explore these prognostic implications and their relevance in determining the utility of intracranial intervention.
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Comparative Study
Comparison of antithrombogenic coated and uncoated flow diverters in ruptured and unruptured cerebral aneurysms.
Flow diversion has become a key treatment option for complex intracranial aneurysms. Recent advancements include coated flow diverters (FDs), designed to potentially reduce the need for dual antiplatelet therapy, thereby removing the associated secondary risks while maintaining patency and low complication rates. Comparing coated and uncoated FDs may offer insights into long-term outcomes and treatment optimization. ⋯ We observed favorable occlusion rates for both coated and uncoated FDs. The role of dual antiplatelet therapy remains debated. Large multicenter studies are essential to evaluate the patency of coated compared to uncoated FDs and determine whether they can reduce thrombogenicity, potentially allowing for less or no antiplatelet therapy in emergencies.
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In idiopathic normal pressure hydrocephalus (iNPH) patients, cerebrospinal fluid (CSF) flow is typically evaluated with a cardiac-gated two-dimensional (2D) phase-contrast (PC) MRI through the cerebral aqueduct. This approach is limited by the evaluation of a single location and does not account for respiration effects on flow. In this study, we quantified the cardiac and respiratory contributions to CSF movement at multiple intracranial locations using a real-time 2D PC-MRI and evaluated the diagnostic value of CSF dynamics biomarkers in classifying iNPH patients. ⋯ Evaluation of CSF movement beyond the cerebral aqueduct may aid in identifying patients with and understanding the pathophysiology of iNPH.
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Observational Study
Transcranial Doppler Arterial Pressure Gradient Is Associated With Delayed Infarction After Subarachnoid Hemorrhage.
While the pulsatility index (PI) measured by transcranial Doppler (TCD) has broader associations with outcomes in neurocritical care, its use in monitoring delayed cerebral infarction (DCI) in patients with aneurysmal subarachnoid hemorrhage (SAH) is not endorsed by current clinical guidelines. Recognizing that arterial pressure gradient (ΔP) can be estimated using PI, we investigated the potential significance of TCD-estimated ΔP. ⋯ Increased ΔP, rather than elevated mCBFV, was associated with DCI. While elevated mCBFV was associated with vasospasm, it was not associated with DCI. Hence, TCD-estimated ΔP may serve as a predictor for the DCI in SAH patients, a condition that impacts long-term outcome.
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This study presents automated atlas-based magnetization transfer (MT) measurements of the typically developing pediatric cervical spinal cord (SC). We report normative MT ratio (MTR) values from the whole cervical cord white matter (WM) and WM tracts, examining variations with age, sex, height, and weight. ⋯ This study provides an understanding of MTR values in pediatric cervical SC and their variations by sex, age, height, and weight, providing a baseline for comparisons in pediatric SC diseases.