Articles: brain-pathology.
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Modern neuronavigation systems lack spatial accuracy during ongoing surgical procedures because of increasing brain deformation, known as brain shift. Intraoperative magnetic resonance imaging was used for quantitative analysis and visualization of this phenomenon. ⋯ Without brain shift compensation, neuronavigation systems cannot be trusted at critical steps of the surgical procedure, e.g., identification of the deep tumor margin. Intraoperative imaging allows not only evaluation of and compensation for brain shift but also assessment of the quality of mathematical models that attempt to describe and compensate for brain shift.
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AJNR Am J Neuroradiol · Nov 2000
Comparative StudyA comparison of magnetization transfer ratio, magnetization transfer rate, and the native relaxation time of water protons related to relapsing-remitting multiple sclerosis.
Magnetization transfer (MT) imaging and measurements of the magnetization transfer ratio (MTR) have extended our capability to depict and characterize pathologic changes associated with multiple sclerosis (MS). We wanted to investigate whether the analysis of other MT parameters, such as magnetization transfer rate (k(for)) and relative measure of water content (T1(free)), adds insight into MS-related tissue changes. ⋯ Estimates of k(for) and T1(free) appear to complement MTR measurements for the understanding of MT changes that occur with different types of MS abnormalities in the brain.
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To explore seizure outcome after surgery for focal epilepsy due to malformation of cortical development (MCD), with focus on the role of MRI. ⋯ Surgery can offer seizure-free outcome for approximately one half of carefully selected patients with intractable focal epilepsy due to MCD. Complete resection of the MRI-apparent lesion may improve the likelihood for favorable outcome. MRI evidence of hemimegalencephaly or bilateral MCD suggests a low likelihood for postoperative freedom from seizures.
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To assess the utility of neuroimaging in the evaluation of children presenting with two of the most common forms of headache, migraine and chronic daily headache, and to determine the utility and pathological yield of neuroimaging in specific headache syndromes in children whose neurological examinations are normal. ⋯ The yield of neuroimaging in children with uncomplicated migraine and normal neurological examination was 3.7%. The yield in children with chronic daily headache and normal neurological examination was higher at 16.6%. The abnormalities discovered included arachnoid cysts, Chiari I malformations, sinus disease, occult vascular malformations and "dilated Virchow-Robin spaces." While none of the neuroimaging findings were apparent clinically, their discovery did not influence the diagnosis, management, or outcome of the patients. None of the abnormalities necessitated surgical intervention or were associated with the headache presentation. Therefore, neuroimaging is not warranted in children and adolescents with defined clinical headache syndrome diagnoses whose neurological examinations are normal.