AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Feb 1999
Comparative StudyComparison of ultrasmall particles of iron oxide (USPIO)-enhanced T2-weighted, conventional T2-weighted, and gadolinium-enhanced T1-weighted MR images in rats with experimental autoimmune encephalomyelitis.
Ultrasmall particles of iron oxide (USPIO) constitute a contrast agent that accumulates in cells from the mononuclear phagocytic system. In the CNS they may accumulate in phagocytic cells such as macrophages. The goal of this study was to compare USPIO-enhanced MR images with conventional T2-weighted images and gadolinium-enhanced T1-weighted images in a model of experimental autoimmune encephalomyelitis (EAE). ⋯ The high sensitivity of USPIO for macrophage activity relative to other imaging techniques is explained by the histologic findings of numerous perivascular cell infiltrates, including macrophages, in EAE. This work supports the possibility of intracellular USPIO transport to the CNS by monocytes/macrophages, which may have future implications for imaging of human inflammatory diseases.
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AJNR Am J Neuroradiol · Feb 1999
Case ReportsRamsay Hunt syndrome associated with brain stem enhancement.
Postcontrast T1-weighted MR images in a patient with Ramsay Hunt syndrome showed an enhancing lesion in the region of the nucleus of the pontine facial nerve and abnormal enhancement of the intrameatal, labyrinthine, and tympanic facial nerve segments and of the geniculate ganglion, as well as enhancement of the vestibulocochlear nerve and parts of the membranous labyrinth. This enhancement most probably resulted from a primary neuritis of the intrameatal nerve trunks of the seventh and eighth cranial nerves.
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AJNR Am J Neuroradiol · Nov 1998
Case ReportsIsolated vagal nerve palsy associated with a dissection of the extracranial internal carotid artery.
A 40-year-old man had paralysis of the right vocal cord. Imaging showed a dissection of the extracranial internal carotid artery, and physical examination disclosed paresis of the right side of the soft palate. ⋯ Most often, multiple lower cranial nerves are involved. The CT, MR imaging, and MR angiographic findings are presented and the topic is reviewed.
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AJNR Am J Neuroradiol · Nov 1998
Sensitivity of enhanced MR in multiple sclerosis: effects of contrast dose and magnetization transfer contrast.
New strategies have been developed to improve the sensitivity of contrast-enhanced MR imaging in quantifying disease activity in patients with multiple sclerosis (MS). The goal of the present study was to evaluate the sensitivity of T1-weighted images after injection of a triple dose of contrast material and application of a magnetization transfer (MT) pulse in the detection of enhancing lesions as compared with the conventional approach. ⋯ The use of a triple dose of contrast material is the best approach to maximize the sensitivity of enhanced MR imaging.
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AJNR Am J Neuroradiol · Nov 1998
Sonographic ventriculography: a new potential use for sonographic contrast agents in neonatal hydrocephalus.
Sonographic identification of communicating and noncommunicating forms of posthemorrhagic hydrocephalus can be difficult. This study evaluates the feasibility of using sonographic contrast agents to determine ventricular patency in a newborn animal model. ⋯ Contrast-enhanced sonographic ventriculography has the potential to identify patency of CSF pathways in newborns with hydrocephalus and an indwelling ventricular catheter.