Journal of neuroimaging : official journal of the American Society of Neuroimaging
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We detail a procedure for generating a set of templates for the hippocampal region in magnetic resonance (MR) images, representative of the clinical conditions of the population under investigation. ⋯ This study describes a simple and easily reproducible procedure to generate templates for the hippocampal region. It can be generalized and applied to other brain regions, which may be relevant for neuroimaging studies.
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Methadone intoxication can cause respiratory depression, leading to hypoxia with subsequent coma and death. Delayed postanoxic leukoencephalopathy (DAL) has been reported with intoxication by carbon monoxide, narcotics, and other toxins. ⋯ Methadone overdose can cause DAL with profound disturbances of neural metabolism and the BBB. The time course of these disturbances can be monitored with MR methods.
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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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Idiopathic intracranial hypertension (IIH), is characterized by elevated intracranial pressure (ICP) without a clear cause. Recently it was shown that in more than 90% of the IIH patients there is stenosis of the transverse dural sinuses. In this study we assessed the changes in diameter of cerebral veins after lumbar puncture, in order to have some more insight regarding the volume and pressure influence on cerebral veins. ⋯ Our results support other studies and demonstrated narrowing of the transverse sinuses in IIH patients. The main finding of this study is the increase in cerebral sinuses diameter after LP. This observation should be considered when evaluating cerebral venous sinuses after LP. A larger scale study is warranted to validate our findings.
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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.