AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Jun 2001
Comparative StudyCerebral hemodynamics in asymptomatic patients with internal carotid artery occlusion: a dynamic susceptibility contrast MR and transcranial Doppler study.
Perfusion imaging with dynamic susceptibility contrast MR imaging (DSC-MRI) has been used to evaluate hemodynamic status in patients with symptomatic occlusive cerebrovascular disease. The aim of the present study was to determine the hemodynamic changes occurring in asymptomatic patients with unilateral internal carotid artery (ICA) occlusion by use of DSC-MRI with transcranial Doppler (TCD) measurement of the breath-holding index (BHI). ⋯ DSC-MRI is a valuable tool for measuring hemodynamic changes in the presence of carotid disease with hemodynamic impairment. In our opinion, hemodynamic changes and efficiency of collateral pathways can be evaluated in occlusive carotid disease by using paired measurement of BHI and DSC-MRI. In the patient group, MR-determined rCBV and TCD-determined BHI showed a significant inverse correlation, suggesting similar significance of the two indices.
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AJNR Am J Neuroradiol · Jun 2001
Comparative StudyQuantitative MR evaluation of intracranial epidermoid tumors by fast fluid-attenuated inversion recovery imaging and echo-planar diffusion-weighted imaging.
Quantification of MR can provide objective, accurate criteria for evaluation of a given MR sequence. We quantitatively compared conventional MR sequences with fast fluid-attenuated inversion recovery (fast-FLAIR) and echo-planar diffusion-weighted (DW) MR imaging in the examination of intracranial epidermoid tumors. ⋯ Fast-FLAIR imaging is superior to conventional MR imaging in depicting intracranial epidermoid tumors. Echo-planar DW imaging provides the best lesion conspicuity among the five MR methods. The hyperintensity of epidermoid tumors on echo-planar DW imaging is not caused by the diffusion restriction but by the T2 shine-through effect.
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AJNR Am J Neuroradiol · Jun 2001
Case ReportsSpontaneous retropharyngeal hematoma: diagnosis by mr imaging.
Spontaneous retropharyngeal hematoma is an uncommon entity that is difficult to diagnose and may progress rapidly to airway obstruction. We report a case of a 53-year-old man with acute onset of retropharyngeal pain, dysphonia, and dysphagia after vomiting. ⋯ MR imaging demonstrated blood products, suggesting a diagnosis of retropharyngeal hematoma, and the patient was managed conservatively. MR imaging allowed specific diagnosis of a rare condition that is otherwise difficult to diagnose without surgical intervention.
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AJNR Am J Neuroradiol · Jun 2001
Transient MR signal changes in patients with generalized tonicoclonic seizure or status epilepticus: periictal diffusion-weighted imaging.
Our purpose was to investigate transient MR signal changes on periictal MR images of patients with generalized tonicoclonic seizure or status epilepticus and to evaluate the clinical significance of these findings for differential diagnosis and understanding of the pathophysiology of seizure-induced brain changes. ⋯ The MR signal changes that occur after generalized tonicoclonic seizure or status epilepticus are transient increase of signal intensity and swelling at the cortical gray matter, subcortical white matter, or hippocampus on periictal T2-weighted and diffusion-weighted images. These findings reflect transient cytotoxic and vasogenic edema induced by seizure. The reversibility and typical location of lesions can help exclude the epileptogenic structural lesions.