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Molecular imaging techniques have rapidly progressed over recent decades providing unprecedented in vivo characterization of metabolic pathways and molecular biomarkers. Many of these new techniques have been successfully applied in the field of neuro-oncological imaging to probe tumor biology. Targeting specific signaling or metabolic pathways could help to address several unmet clinical needs that hamper the management of patients with brain tumors. This review aims to provide an overview of the recent advances in brain tumor imaging using molecular targeting with positron emission tomography and magnetic resonance imaging, as well as the role in patient management and possible therapeutic implications., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Objectives: To assess whether there is mid-term reorganization in brain networks connectivity after Carotid Endarterectomy (CEA) using resting state functional connectivity Magnetic Resonance (fc-rsMR), with a special focus on the Default Mode Network (DMN)., Materials and Methods: In this prospective exploratory study, 14 asymptomatic consecutive patients (10 males and 4 females, mean age 73.5) with unilateral, significant ICA stenosis eligible for CEA according to European Society for Vascular Surgery guidelines were prospectively recruited. The week before CEA procedure, each patient underwent both neurocognitive and rs-fcMR evaluations on the same day; the neurocognitive test consisted on a Mini Mental State Examination (MMSE). The same neurocognitive test and rs-fcMR examination were repeated on follow-up between 3-6 months after CEA. MMSE scores were compared using paired T-Student Test. Rs-fcMR Region Of Interest (ROI-to-ROI) and Seed-to-voxel group analysis were conducted using the CONN toolbox v18 and the SPM 12 software., Results: Patients showed improvements in MMSE scores from before to after CEA (p-value = 0.0001). ROI-to-ROI analysis revealed several statistically significant connectivity changes following CEA, both in terms of positive and negative correlations; Seed-to-Voxel focusing on DMN revealed increased connectivity between medial prefrontal cortex (mPFC) and three different clusters of voxels., Conclusions: CEA procedure is associated with an improvement in neurocognitive performance (according to MMSE testing) and reorganization of functional connectivity, including the DMN. These results represent a starting point in order to design further studies for a better understanding of the reorganization of brain networks following CEA, and to investigate the potential role of CEA as a therapeutic procedure for cognitive impairments in selected patients with critical ICA stenosis., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background and Purpose: Hepatitis C virus (HCV) co-infection's role on cognitive impairment of human immunodeficiency virus (HIV) positive patients is still debated and functional neuroimaging evaluation on this matter is lacking. To provide further insight about HCV's neuro-effects on HIV associated neurocognitive disorder (HAND), we performed a pilot resting state (RS) functional connectivity magnetic resonance imaging (fcMRI) study to find eventual functional connectivity alteration that could reflect HCV related cognitive performance degradation., Methods: Eighteen patients (8 HIV, 10 HIV + HCV), either impaired or not impaired, were assessed with RS fcMRI. A statistic model including cognitive testing results was elaborated during data processing to evaluate brain networks alteration related to actual cognitive status in patients., Results: Statistically significant different patterns of connectivity were found: HCV co-infection modified 17 ROIs' connectivity with 45 supra-threshold connections (p-FDR min 0.0022, max 0.0497). ROIs most involved were right pallidum, brainstem, vermian lobules 1-2 and right cerebellar lobule 10. Graph theory analysis did not demonstrate significant difference between networks, but HCV related modifications at ROI's local level were found, with particular involvement of ROIs of frontal lobe, basal ganglia and cerebellum. Increased fronto-striatal dysfunctions have been already reported as consequences of HCV infection and could reflect an additive effect. Cerebellar alterations are associated with HIV and HAND, but not with HCV infection, suggesting a synergic effect of HCV., Conclusion: Our study demonstrates RS fcMRI can help to understand the interactions between HIV and HCV co-infection, and our preliminary results suggest synergic effects of HCV in HIV-related brain functional modification., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Purpose: We aimed to assess if there is a difference of distribution and volume of white matter hyperintensities (WMH) in the brain according to the Circle of Willis (CoW) configuration in patients with carotid artery pathology., Material and Methods: One-hundred consecutive patients (79 males, 21 females; mean age 70 years; age range 46-84 years) that underwent brain MRI before carotid endarterectomy (CEA) were included. FLAIR-WMH lesion volume was performed using a semi-automated segmentation technique and the status of the circle of Willis was assessed by two neuroradiologists in consensus., Results: We found a prevalence of 55% of variants in the CoW configuration; 22 cases had one variants (40%); 25 cases had two variants (45.45%) and 8 cases showed 3 variants (14.55%). The configuration that was associated with the biggest WMH volume and number of lesions was the A1+PcoA+PcoA. The PcoA variants were the most prevalent and there was no statistically significant difference in number of lesions and WMH for each vascular territory assessed and the same results were found for AcoA and A1 variants., Conclusion: Results of our study suggest that the more common CoW variants are not associated with the presence of an increased WMH or number of lesions whereas uncommon configurations, in particular when 2 or more segment are missing increase the WMH volume and number of lesions. The WHM volume of the MCA territory seems to be more affected by the CoW configuration., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Purpose: To assess the feasibility of using an ultra-low dose (0.05 mmol/kg of body weight [BW]) of high relaxivity contrast agent for late gadolinium enhancement (LGE) imaging in patients with acute myocardial infarction (AMI)., Materials and Methods: 17 consecutive patients (mean age, 60.1 ± 10.3 years) with ST-segment elevation AMI underwent two randomized cardiac magnetic resonance studies (exam intervals between 24 and 48h) on a 1.5T unit during the first week after the event using gadobenate dimeglumine (Gd-BOPTA) at the dose of 0.1 mmol/kg BW (standard dose or SD group) and 0.05 mmol/kg BW (half dose or HD group). Image quality was qualitatively assessed. Quantitative analysis of LGE were performed by measuring signal intensity (SI), signal-to-noise ratio (SNR) in the infarcted myocardium (IM), non-infarcted myocardium (N-IM) and left ventricular cavity (LVC) in images acquired at 1, 3, 5, 10, 15 and 20 min after administration of Gd-BOPTA using both contrast media protocol. Contrast-to-noise ratio (CNR) between IM and N-IM (CNR IM/N-IM) and between IM and LVC (CNR IM/LVC) were also quantified for each time point. Moreover the extent of infarcted myocardium was measured., Results: 102 LGE images were evaluated for each dose group. Quality score was significantly higher for SD at 1, 15 and 20 min (0.002