Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Medial lemniscus T2 hyperintensity (MLH) has been recently demonstrated as potential imaging marker for small vessel disease (SVD). Our purpose in this study is to improve accuracy of regions of interest (ROI) analysis for this imaging finding. ⋯ MLH seen on high threshold ROI analysis is a reliable radiologic marker in predicting SVD. ROI analysis of MLH should be performed by an experienced neuroradiologist.
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Observational Study
Transcranial Doppler velocities in a large, healthy population.
Transcranial Doppler (TCD) ultrasonography has been extensively used in the evaluation and management of patients with cerebrovascular disease since the clinical application was first described in 1982 by Aaslid and colleagues TCD is a painless, safe, and noninvasive diagnostic technique that measures blood flow velocity in various cerebral arteries. Numerous commercially available TCD devices are currently approved for use worldwide, and TCD is recognized to have an established clinical value for a variety of clinical indications and settings. Although many studies have reported normal values, there have been few recently, and none to include a large cohort of healthy subjects across age, race, and gender. As more objective, automated processes are being developed to assist with the performance and interpretation of TCD studies, and with the potential to easily compare results against a reference population, it is important to define stable normal values and variances across age, race, and gender, with clear understanding of variability of the measurements, as well as the yield from various anatomic segments. ⋯ Our study provides normal, reference TCD values for a large cohort of healthy subjects across a wide range of age, sex, and race groups. We observed decreased MBFV and increased PI with aging, and higher MBFV in women. There were few differences in MBFV related to side or ethnicity, but the MFBV and PI changes with age were specific to Caucasians. We provide means and standard deviations of MBFVs across various demographic groups in key intracranial arteries. Such normal TCD values across age, gender, and ethnic groups in healthy subjects represent a useful reference tool for detecting individuals with TCD values outside normal limits and at increased vascular risk. TCD studies in large multiethnic populations are still required to determine differences in brain hemodynamics across various ethnic groups.
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Clinical Trial
Arterial spin labeling identifies tissue salvage and good clinical recovery after acute ischemic stroke.
Arterial spin labeling (ASL) is a relatively new MR perfusion technique that requires validation. ⋯ Hyperperfusion of the initially ischemic area identified on ASL at 24 hours poststroke identifies patients with better tissue and clinical outcomes.
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Juvenile xanthogranuloma (JXG) is a disorder of non-Langerhans cell histiocytosis that usually displays as a self-limiting course in children. Rare systemic involvement implies poor prognosis. Although conventional and spectroscopic magnetic resonance imaging (MRI) findings of JXG in CNS have been described, diffusion imaging of intracranial JXG has not been reported. ⋯ Intravenous steroid therapy is initiated in intensive care setting. All of the lesions have gradually responded to steroid therapy. CNS lesion has taken the longest time to clear.
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Diffusion tensor imaging (DTI) quantifies the motion of water within brain tissue. Inflammation leads to tissue disruption, resulting in increased diffusivity and decreased directionality. We aimed to quantify the damage within tumefactive giant brain lesions (TGL) in multiple sclerosis (MS) using MRI and DTI methodology. ⋯ Within the spectrum of acute MS lesions, TGL present DTI metrics of an intense acute inflammatory process. Analysis of TGL progression proposes that DTI metrics sensitively detects micro-structural changes in TGL from acute inflammation towards lesion recovery and reorganization.