AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Oct 2004
Selective lumbar nerve root blocks with CT fluoroscopic guidance: technique, results, procedure time, and radiation dose.
CT fluoroscopy may be used as a rapid and effective means of guiding needle placement when performing selective lumbar nerve root blocks. In this set of patients, the average external radiation dose was 0.73 mrem per procedure, with an average of 2 seconds of CT-fluoroscopy time and four images per procedure. Average physician room time was 7 minutes. Use of intermittent CT fluoroscopy during lumbar selective nerve root blocks can result in minimal radiation dose levels and procedure times that are comparable to fluoroscopic guidance.
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AJNR Am J Neuroradiol · Oct 2004
Multiparametric iterative self-organizing MR imaging data analysis technique for assessment of tissue viability in acute cerebral ischemia.
Defining viability and the potential for recovery of ischemic brain tissue can be very valuable for patient selection for acute stroke therapies. Multiparametric MR imaging analysis of ischemic lesions indicates that the ischemic lesion is inhomogeneous in degree of ischemic injury and recovery potential. We sought to define MR imaging characteristics of ischemic lesions that are compatible with viable tissue. ⋯ ISODATA multiparametric MR imaging of acute stroke clearly shows inhomogeneity and different viability of the ischemic lesion. Ischemic tissues with lower acute phase ISODATA tissue signature values (< or = 4) and higher rADC values (> or = 0.79) are much more likely to recover than those with higher signature values or lower rADC values. The effect of these factors on tissue recovery, however, is dependent on whether preceding treatment with rt-PA had been performed. Our approach can be a valuable tool in the design of therapeutic stroke trials with an extended time window.
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AJNR Am J Neuroradiol · Sep 2004
Case ReportsSerial antenatal sonographic observation of cerebral dural sinus malformation.
Dural sinus malformation is an extremely rare congenital cerebrovascular malformation. We report serial antenatal sonographic findings in two patients with dural sinus malformation. Sonography can reveal dural sinus malformation at 24 weeks' gestation. Correct and early diagnosis may help determine the appropriate place, timing, and mode of delivery, which may result in a better therapeutic course and patient outcome.
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AJNR Am J Neuroradiol · Sep 2004
Case ReportsMultiple cerebral aneurysms and subarachnoid hemorrhage in a patient with Alagille syndrome.
Although intracranial hemorrhage has frequently been found responsible for mortality in adult patients with Alagille syndrome (AGS), no specific underlying cause has been identified. We describe the case of severe subarachnoid hemorrhage in a 30-year-old woman harboring five intracranial aneurysms and multiple peripheral vascular anomalies. To evaluate a possible higher incidence of intracranial aneurysms, a study of the cerebral vasculature in all AGS patients by using noninvasive imaging techniques should be considered.
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AJNR Am J Neuroradiol · Sep 2004
Diffusion-weighted MR imaging in acute ischemia: value of apparent diffusion coefficient and signal intensity thresholds in predicting tissue at risk and final infarct size.
Identifying tissue at risk for infarction is an important goal of stroke imaging. This study was performed to determine whether pixel-based apparent diffusion coefficient (ADC) and signal intensity ratio are helpful diffusion-weighted (DW) imaging metrics to predict tissue at risk for infarction. ⋯ Pixel-based thresholds applied to ADC or DW image signal intensity maps were not accurate prognostic measures of tissue at risk. Quantitative DW images or ADC maps may provide added information not obtained by visual inspection of the qualitative DW image map.