Neuroimaging clinics of North America
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Neuroimaging Clin. N. Am. · Feb 2003
ReviewVenous congestive encephalopathy related to cranial dural arteriovenous fistulas.
Cranial DAVFs present with a wide spectrum of clinical findings from pulsatile tinnitus alone to intracranial hemorrhage and NHND. The neurologic sequelae are a consequence of venous hypertension and venous congestion. DAVFs with CVR can present with or develop a VCE that can be recognized on MR imaging as a diffuse T2 hyperintensity in the deep white matter of the cerebral or cerebellar hemispheres. ⋯ The telltale sign on MR imaging is the plethora of prominent pial vessels on the surface of the brain that are the engorged cortical veins participating in the cortical venous reflux. Selective angiography is critical for the accurate assessment of the CVR. DAVFs with CVR require prompt treatment, either endovascular alone or a combination of endovascular treatment and surgery.
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Neuroimaging Clin. N. Am. · Feb 2003
ReviewCerebral venous thrombosis in adults: the role of imaging evaluation and management.
Clinical suspicion and excellent neuroimaging are crucial in making a diagnosis of CVT. Intravascular or dural sinus thrombus can be visualized on CT and MRI. ⋯ Heparin treatment is accepted as the first-line treatment of CVT. Endovascular treatment for management of CVT is usually reserved for selected cases after failure of anticoagulation.
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Neuroimaging Clin. N. Am. · Feb 2003
ReviewRadiologic findings and clinical significance of venous compartment of brain arteriovenous shunts.
The venous compartment of brain AVS is closely related to the development of various clinical consequences, including hemorrhage, seizure, and neurologic deficit. Therefore, understanding the venous etiology of the clinical symptoms and the imaging characteristics of partial or complete venous outlet thrombosis is critical for the proper management of patients with brain AVSs.
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Neuroimaging Clin. N. Am. · Nov 2002
ReviewCharacterization of untreated gliomas by magnetic resonance spectroscopic imaging.
Although there are trends in the morphologic, metabolic, hemodynamic, and structural properties of untreated gliomas that are reflected in MR measurements, there is considerable heterogeneity both within and between lesions of the same histologic grade. The spatial extent of the abnormality in ADC and RA images is similar to the T2 lesion, but there is no obvious difference in intensity between grades. The rCBV is significantly increased in the enhancing volume of grade 4 lesions but is similar or reduced in intensity for most grade 3 lesions. ⋯ The correlations between rCBV, Cho, and ADC suggest that cellularity, membrane turnover, and vascularity are linked in grade 4 lesions. It is not clear whether there is any relationship between these parameters regions in grade 2 or grade 3 gliomas. While further work is required to optimize the methodology associated with these MR parameters, it seems likely that combining the information from such measurements may be valuable for predicting outcome and tailoring therapy to individual patients.
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Neuroimaging Clin. N. Am. · Nov 2002
ReviewViral imaging in gene therapy noninvasive demonstration of gene delivery and expression.
Gene therapy is a rapidly developing modality of treatment, with applications in acquired and inherited disorders. Gene delivery vehicles ("vectors") are the main impediment in the evolution of gene therapy into a clinically acceptable mainstream therapy. Vectors based on viral particles are the most commonly used vehicles to carry genes to the organs and tissues of interest. ⋯ Recent progress in viral vector production and better understanding of molecular aspects of vector delivery and targeting issues has created the need for imaging techniques that would be useful in addressing the problems and opportunities inherent in viral gene therapy development. Two integral components of gene therapy monitoring, the imaging of gene delivery and the imaging of resultant exogenous gene expression, are recognized. These molecular imaging components provide a realistic means for assessment of safety and efficacy of preclinical and clinical development of gene therapy.