Journal of neuroimaging : official journal of the American Society of Neuroimaging
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The safety and feasibility of intravenous thrombolysis using recombinant tissue plasminogen activator (IV-tPA) were retrospectively compared between patients with unknown onset time and no ischemia on fluid-attenuated inversion recovery (negative FLAIR) and patients receiving standard therapy. ⋯ IV-tPA may safely increase the rate of dramatic recovery in acute stroke patients with unknown onset times and negative FLAIR.
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Carotid artery atherosclerotic plaque composition may influence plaque stability and risk of thromboembolic events, and noninvasive plaque imaging may therefore permit risk stratification for clinical management. Plaque composition was compared using noninvasive in vivo (3T) and ex vivo (7T) MRI and histopathological examination. ⋯ This study provides evidence that semiautomated segmentation of 3T/7T MRI techniques can help to determine atherosclerotic plaque composition. In particular, the high resolution of ex vivo 7T data was able to highlight greater detail in the atherosclerotic plaque composition. High-field MRI may therefore have advantages for in vivo carotid plaque MRI.
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Change in lesion volume over time, measured on brain magnetic resonance imaging (MRI) scans, is an important outcome measure for natural history studies and clinical trials in multiple sclerosis (MS). ⋯ Use of the subtraction algorithm leads to improved reliability and lower operator fatigue in clinical trials and studies of the natural history of MS.
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Comparative Study
The Effect of Endogenous Adenosine on Neuronal Activity in Rats: An FDG PET Study.
2-(18) F-fluorodeoxy-D-glucose (FDG) is a glucose analog that is taken up by cells and phosphorylated. The amount of FDG accumulated by cells is a measure of the rate of glycolysis, which reflects cellular activity. As the levels and actions of the neuromodulator adenosine are dynamically regulated by neuronal activity, this study was designed to test whether endogenous adenosine affects tissue accumulation of FDG as assessed by positron emission tomography (PET) or by postmortem analysis of tissue radioactivity. ⋯ Whole-brain FDG uptake was not affected by drug treatment. Significant regional hypometabolism was detected, particularly in cerebellum, of DPCPX- and ABT-702 treated rats, relative to vehicle-treated rats. Thus, endogenous adenosine can affect FDG accumulation although this effect is modest in quiescent rats.
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The additional information that transcranial Doppler (TCD) can provide as part of a multimodal imaging stroke protocol in the setting of hyper acute strokes has not been evaluated. ⋯ TCD in the first 4.5 hours of acute ischemia can provide additional information to a multimodal acute ischemic stroke imaging protocol, and can induce changes in the management of a proportion of these patients.