AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Feb 2002
Cerebral ischemia detected with diffusion-weighted MR imaging after stent implantation in the carotid artery.
Concern regarding the safety of stent implantation in the carotid artery exists because of the risk of cerebral embolization during the procedure. The purpose of this prospective study was to determine the incidence of new areas of cerebral ischemia, as detected by using diffusion-weighted MR imaging after stent implantation in the carotid artery. ⋯ In 29% of the procedures, stent implantation in the carotid artery was associated with new areas of cerebral ischemia, as detected by using diffusion-weighted MR images; these findings indicated the occurrence of cerebral microemboli during such procedures. In all patients except one, the new lesions were clinically silent.
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AJNR Am J Neuroradiol · Jan 2002
High-resolution line scan diffusion tensor MR imaging of white matter fiber tract anatomy.
MR diffusion tensor imaging permits detailed visualization of white matter fiber tracts. This technique, unlike T2-weighted imaging, also provides information about fiber direction. We present findings of normal white matter fiber tract anatomy at high resolution obtained by using line scan diffusion tensor imaging. ⋯ We obtained a complete set of detailed white matter fiber anatomy maps of the normal brain by means of line scan diffusion tensor imaging at high resolution. Near large bone structures, line scan produces images with minimal susceptibility artifacts.
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AJNR Am J Neuroradiol · Jan 2002
Comparative StudyProspective evaluation of suspected stenoocclusive disease of the intracranial artery: combined MR angiography and CT angiography compared with digital subtraction angiography.
MR angiography is primarily and increasingly used to assess intracranial arterial stenoocclusion. However, MR angiography can cause overestimation of stenosis. Although CT angiography is accurate, it has limitations. Our purpose was to determine whether the accuracy of combined MR angiography and CT angiography is equal to that of digital subtraction angiography (DSA) in measuring stenosis and detecting major intracranial arterial occlusion. ⋯ In this investigation, the evaluation of suspected stenoocclusive diseases in major intracranial arteries, the accuracy of combined MR angiography and CT angiography is equal to that of DSA in most cases.
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AJNR Am J Neuroradiol · Jan 2002
Abnormalities in the recirculation phase of contrast agent bolus passage in cerebral gliomas: comparison with relative blood volume and tumor grade.
Abnormalities in the recirculation phase of the passage of a contrast agent bolus have been identified in tumors and have been suggested to represent vascular tortuosity and hypoperfusion in areas of angiogenic neovascularization. This study was performed to examine the hypothesis that these abnormalities provide information concerning the microcirculation related to tumor grade in patients with cerebral glioma. ⋯ Variation in the recirculation characteristics of a contrast agent bolus is related to tumor grade in gliomas. This supports the hypothesis that abnormalities in contrast agent recirculation provide independent information concerning the microcirculation in imaging studies of angiogenesis and may be of value as surrogate markers in trials of antiangiogenic therapy.
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AJNR Am J Neuroradiol · Jan 2002
Radiology resident evaluation of head CT scan orders in the emergency department.
Prior studies have revealed little difference in residents' abilities to interpret cranial CT scans. The purpose of this study was to assess the performance of radiology residents at different levels of training in the interpretation of emergency head CT images. ⋯ The level of resident training has a significant effect on the rate of disagreement between the preliminary interpretations of emergency cranial CT scans by residents and the final interpretations by neuroradiologists. Efforts to reduce residents' errors should focus on the identification of fractures and signs of chronic ischemic change.