AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Mar 2000
A CT method to measure hemodynamics in brain tumors: validation and application of cerebral blood flow maps.
CT is an imaging technique that is routinely used for evaluating brain tumors. Nonetheless, imaging often cannot show the distinction between radiation necrosis and neoplastic growth among patients with recurrent symptoms after radiation therapy. In such cases, a diagnostic tool that provides perfusion measurements with high anatomic detail would show the separation between necrotic areas, which are characterized by low perfusion, from neoplastic areas, which are characterized by elevated CBF. We attempted to validate a dynamic contrast-enhanced CT method for the measurement of regional CBF in brain tumors, and to apply this method by creating CBF maps. ⋯ The dynamic CT method presented herein provides absolute CBF measurements in brain tumors that are accurate and precise. Preliminary CBF maps derived with this method demonstrate their potential for depicting areas of different blood flow within tumors and surrounding tissue, indicating its possible use in the clinical setting.
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AJNR Am J Neuroradiol · Mar 2000
Pure sensory stroke caused by a cerebral hemorrhage: clinical-radiologic correlations in seven patients.
Pure sensory stroke (PSS) usually is caused by a lacunar infarct; reports of PSS caused by cerebral hemorrhage have been rare. We correlated clinical and neuroradiologic findings in patients with PSS caused by cerebral hemorrhage. ⋯ Focal hemorrhages can lead to purely sensory stroke syndromes, and the clinical deficits are fairly well linked with the locations of the bleeds.
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AJNR Am J Neuroradiol · Mar 2000
Contrast-enhanced transcranial color-coded duplexsonography in stroke patients with limited bone windows.
Thickening of the temporal bone in stroke-age patients may obviate sonographic evaluation of the circle of Willis in 20% to 30% of patients. We assessed the diagnostic efficacy of contrast-enhanced transcranial color-coded duplexsonography (TCCD) for noninvasive evaluation of the circle of Willis in stroke patients with limited bone windows. ⋯ In stroke-age patients with limited acoustic windows, contrast-enhancement with Levovist can markedly increase the sensitivity of TCCD and increase the detection of clinically relevant intracranial arterial disease.
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AJNR Am J Neuroradiol · Mar 2000
Case ReportsDiffuse vasospasm after pretruncal nonaneurysmal subarachnoid hemorrhage.
Pretruncal (perimesencephalic) nonaneurysmal hemorrhage is a benign form of subarachnoid hemorrhage (SAH). Angiographic changes of vasospasm are uncommon in patients with this type of hemorrhage, and if vasospasm is present, it is mild and focal. We report two patients with pretruncal nonaneurysmal SAH who developed severe and diffuse vasospasm, expanding the clinical spectrum of this type of SAH. ⋯ Nine hours later, the patient developed transient dysphasia, and she was treated with hypervolemia. Three days later, a transcranial Doppler examination showed normalization of blood velocities. The presence of diffuse and severe vasospasm does not exclude a diagnosis of pretruncal nonaneurysmal SAH.
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AJNR Am J Neuroradiol · Mar 2000
Screening CT of the brain determined by CD4 count in HIV-positive patients presenting with headache.
Few studies have examined HIV-positive patients presenting with uncomplicated headache for clinical variables that might be predictive of those patients who would most benefit from CT. Because of the value of CD4 counts in predicting the relative risk of developing opportunistic infections and neoplasms, we assessed the diagnostic yield of screening CT in HIV-positive patients presenting with headache as sorted by CD4 count. ⋯ A recent CD4 count provides an important predictor variable when considering performing CT in HIV-positive patients presenting with uncomplicated headache. Performing CT of the head for patients with CD4 counts equal to or greater than 200 cells/microL is of questionable value considering the low prevalence of positive CT findings. For this select group of patients, MR imaging may be more appropriate than CT. Patients with CD4 counts less than 200 cells/microL should undergo CT because of the high prevalence of positive scans.