AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Oct 2007
Diffusion tensor MR imaging tractography of the pyramidal tracts correlates with clinical motor function in children with congenital hemiparesis.
Children with congenital hemiparesis have greater asymmetry in diffusion parameters of the pyramidal tracts compared with control subjects. We hypothesized that the asymmetry correlates with the severity of hemiparesis and that diffusion metrics would be abnormal in the affected tracts and normal in the unaffected tracts. ⋯ Asymmetry in fractional anisotropy, transverse diffusivity, and mean diffusivity, as well as the degree of abnormality in the actual values of the affected pyramidal tracts themselves, correlates with the severity of motor dysfunction in infants and children with congenital hemiparesis from different causes. This suggests that abnormalities detected by diffusion tensor MR imaging tractography in the affected pyramidal tract are related to the functional ability of the affected pyramidal tract, regardless of the etiology of motor dysfunction.
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AJNR Am J Neuroradiol · Oct 2007
Case ReportsTreatment of carotid cavernous fistulas using covered stents: midterm results in seven patients.
Carotid cavernous fistulas (CCF) can be effectively treated by using different therapeutic alternatives such as detachable balloons and detachable coils, alone or in combination with N-butyl-2-cyanoacrylate (n-BCA) or Onyx. Stents have also been used in an attempt to improve preservation of the parent artery while still occluding the fistula. We present our experience using balloon-expandable covered stents to treat CCF, focusing on arterial wall reconstruction. To our knowledge, this is the first series with midterm follow-up between 3 months and 3.5 years. ⋯ PTFE-covered stents are evolving as a promising intracranial therapeutic alternative to treat CCF and preserve the parent artery by reconstructing the arterial wall. They should be considered in patients in whom fistulas cannot be successfully occluded with detachable balloons or detachable coils. More investigation is required to further develop their specifications and indications.
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AJNR Am J Neuroradiol · Oct 2007
MR imaging of metronidazole-induced encephalopathy: lesion distribution and diffusion-weighted imaging findings.
MR imaging features of metronidazole-induced encephalopathy (MIE) have not been fully established. This study was undertaken to determine the topographic distributions and diffusion-weighted imaging (DWI) findings of MIE. ⋯ Brain lesions were typically located at the cerebellar dentate nucleus, midbrain, dorsal pons, medulla, and splenium of the corpus callosum. According to DWI, most of the lesions in MIE probably corresponded to areas of vasogenic edema, whereas only some of them, located in the corpus callosum, corresponded to cytotoxic edema.
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AJNR Am J Neuroradiol · Oct 2007
Characteristics of abnormal diffusivity in normal-appearing white matter investigated with diffusion tensor MR imaging in tuberous sclerosis complex.
Although patients with tuberous sclerosis complex (TSC) manifest various structural abnormalities, we hypothesized that white matter (WM) structures that appear normal on conventional MR imaging may be accompanied by microstructural changes, such as gliosis and myelinization defects. Our objective was to determine in vivo whether there was evidence for WM microstructural changes by using diffusion tensor imaging (DTI). ⋯ Our findings revealed a decrease in anisotropy and an increase in longitudinal and radial diffusivities in NAWM beyond the location of TSC lesions seen on conventional MR imaging. The axonal microstructural changes suggested by our study may be related to changes in myelin packing due to giant cells accompanied by gliosis and myelination defects known to occur in TSC WM.
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AJNR Am J Neuroradiol · Sep 2007
Review Case ReportsAutosomal recessive spastic ataxia of Charlevoix-Saguenay: a report of MR imaging in 5 patients.
We present findings on MR imaging in 5 patients with autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). In the literature, early atrophy of the superior vermis as well as progressive atrophy of the cerebellar hemispheres and cervical cord was described. We found linear hypointensity on T2 and T2 fluid-attenuated inversion recovery-weighted images in the pons in all of our 5 patients.