AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Jan 2014
Randomized Controlled TrialOptimal contrast concentration for CT-guided epidural steroid injections.
Contrast is used in CT-guided epidural steroid injections to ensure proper needle placement. Once injected, undiluted contrast often obscures the needle, hindering subsequent repositioning. The purpose of this investigation was to establish the optimal contrast dilution for CT-guided epidural steroid injections. ⋯ For CT-guided epidural steroid injections, the optimal contrast concentration is 66-100 mg/mL iodine. Because these concentrations are not commercially available, proceduralists must dilute their contrast for such procedures.
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AJNR Am J Neuroradiol · Jan 2014
Right insular atrophy in neurocardiogenic syncope: a volumetric MRI study.
Alterations in the central autonomic network are hypothesized to play a role in the pathophysiologic mechanism underlying neurocardiogenic syncope; however, few data are available regarding the structural changes of the brain in this condition. We used voxel-based morphometry and regional volumetry to identify possible neuroanatomic correlates. ⋯ We observed a novel finding of right insular atrophy in patients with neurocardiogenic syncope with a positive response to the head-up tilt test, implicating the role of right insular dysfunction in the pathophysiologic mechanism underlying neurocardiogenic syncope. Our findings further support the hypothesis that right insular dysfunction may cause a decrease in sympathetic activity and a reciprocal increase in parasympathetic activity, leading to syncope.
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AJNR Am J Neuroradiol · Jan 2014
Case ReportsCerebral aneurysms treated with flow-diverting stents: computational models with intravascular blood flow measurements.
Computational fluid dynamics modeling is useful in the study of the hemodynamic environment of cerebral aneurysms, but patient-specific measurements of boundary conditions, such as blood flow velocity and pressure, have not been previously applied to the study of flow-diverting stents. We integrated patient-specific intravascular blood flow velocity and pressure measurements into computational models of aneurysms before and after treatment with flow-diverting stents to determine stent effects on aneurysm hemodynamics. ⋯ Integration of intravascular dual-sensor guidewire measurements of blood flow velocity and blood pressure provided patient-specific computational models of cerebral aneurysms. Aneurysm treatment with flow-diverting stents reduces blood flow and hemodynamic shear stress in the aneurysm dome.
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AJNR Am J Neuroradiol · Jan 2014
Does the location of the arterial input function affect quantitative CTP in patients with vasospasm?
In recent years, there has been increasing use of CTP imaging in patients with aneurysmal SAH to evaluate for vasospasm. Given the critical role of the arterial input function for generation of accurate CTP data, several studies have evaluated the effect of varying the arterial input function location in patients with acute stroke. Our aim was to determine the effect on quantitative CTP data when the arterial input function location is distal to significant vasospasm in patients with aneurysmal SAH. ⋯ Arterial input function placement distal to significant vasospasm does not affect the quantitative CTP data in the corresponding vascular territory or any other vascular territory in aneurysmal SAH.
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AJNR Am J Neuroradiol · Jan 2014
Long-term white matter changes after severe traumatic brain injury: a 5-year prospective cohort.
Extensive white matter damage has been documented in patients with severe traumatic brain injury, yet how this damage evolves in the long term is not well understood. We used DTI to study white matter changes at 5 years after traumatic brain injury. ⋯ DTI changes in major white matter tracts persist up to 5 years after severe traumatic brain injury and are most pronounced in the corpus callosum and corona radiata. Limited structural change is noted in the interval between 2 and 5 years.