Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Review
Transcranial Doppler and Transcranial Color Duplex in Defining Collateral Cerebral Blood Flow.
In an acute stroke setting, transcranial Doppler (TCD) and transcranial color-coded duplex (TCCD) have an important diagnostic utility in the monitoring of an arterial occlusion and microemboli detection. In addition, TCD has proven to be a very useful tool in the detection and progression of cerebral vasospasm in patients with subarachnoid hemorrhage. ⋯ It is a noninvasive technique and can be utilized repeatedly allowing for changes in the blood flow dynamics as treatment is delivered. In this review, we outlined the evolving role of TCD/TCCD in defining CF in patients with an acute ischemic stroke, predicting clinical outcome and monitoring the treatment's efficacy of the CF augmentation.
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Review
Emotional Processing in the First 2 Years of Life: A Review of Near-Infrared Spectroscopy Studies.
Emotional stimuli processing during childhood helps us to detect salient cues in our environment and prepares us for our social life. In early childhood, the emotional valences of auditory and visual input are salient and relevant cues of social aspects of the environment, and it is of special interest to understand how exactly the processing of emotional stimuli develops. Near-infrared spectroscopy (NIRS) is a noninvasive neuroimaging tool that has proven valuable in studying emotional processing in children. ⋯ Our review provides an overview of the database on emotional processing in children up to 2 years of age. Furthermore, it demonstrates the need to include the less-studied age range of 1 to 2 years, and suggests the use of combined audio-visual stimuli and longitudinal studies for future research on emotional processing in children. Thus, NIRS might be a vital tool to study the associations between the early pattern of neural responses and socioemotional development later in life.
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The purpose of this review is to provide an update on technology related to Transcranial Color Coded Doppler Examinations. Microvascularization (MicroV) is an emerging Power Doppler technology which can allow visualization of low and weak blood flows even at high depths, thus providing a suitable technique for transcranial ultrasound analysis. With MicroV, reconstruction of the vessel shape can be improved, without any overestimation. ⋯ In further neurosonology technology development efforts, attempts have been made to address morphology issues and overcome technical limitations. The use of contrast agents has helped in this regard by introducing harmonics and subtraction software, which allowed better morphological studies of vessels, due to their increased signal-to-noise ratio. Having no limitations in the learning curve, in time and contrast agent techniques, and due to its high signal-to-noise ratio, MicroV has shown great potential to obtain the best morphological definition.
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The thalamus is a part of the diencephalon, containing numerous connections between the forebrain and subcortical structures. It serves an important function as a relay center between the cerebral cortex and the subcortical regions, particularly with sensory information. The thalamus also plays a major role in regulating arousal and the levels of awareness. ⋯ In addition, we will also review the variant thalamic territories and associated infarction syndromes of the anteromedian, central, and posterolateral territories. This review article is aimed to better the clinical and radiologic understanding as well as the diagnosis of classic and variant thalamic territory infarcts. This article will also briefly touch on the recovery of function after thalamic infarcts.
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Carotid artery disease (CAD) is a common cause of ischemic stroke with high rates of recurrence. Carotid endarterectomy (CEA) or carotid artery stenting (CAS) are highly recommended for the secondary prevention of symptomatic CAD during the first 14 days following the index event of transient ischemic attack or minor stroke. CEA or CAS may also be offered in selected cases with severe asymptomatic stenosis. ⋯ Carotid ultrasound may provide invaluable information on plaque echogenicity, ulceration, risk of thrombosis, and rupture. Transcranial Doppler or transcranial color-coded sonography may further assist by mapping collateral circulation, evaluating the impairment of vasomotor reactivity, detecting microembolization, or reperfusion hemorrhage in real time. Neurosonology examinations are indispensable bedside tools assisting in the diagnosis, risk stratification, peri-interventional monitoring, and follow-up of patients with CAD.