AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Sep 2006
Randomized Controlled TrialDoes high-field MR imaging have an influence on the classification of patients with clinically isolated syndromes according to current diagnostic mr imaging criteria for multiple sclerosis?
Current MR imaging criteria for multiple sclerosis (MS) do not specify the magnetic field strength. The aim of this study was to investigate whether different MR imaging field strengths, specifically high-field MR imaging, have an impact on the classification of patients with clinically isolated syndromes suggestive of MS, according to MR imaging and diagnostic criteria. ⋯ MR field strength, specifically high-field MR imaging, has a substantial influence on the classification of patients with CIS according to imaging and a mild influence on the classification according diagnostic criteria for MS, leading to consequences for prognostic classification, imaging guidelines, and clinical trials.
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AJNR Am J Neuroradiol · Sep 2006
Effects of number of diffusion gradient directions on derived diffusion tensor imaging indices in human brain.
The effects of a number of diffusion-encoding gradient directions (NDGD) on diffusion tensor imaging (DTI) indices have been studied previously with theoretic analysis and numeric simulations. In this study, we made in vivo measurements in the human brain to compare different clinical scan protocols and to evaluate their effects on the calculated DTI indices. ⋯ For ROI analyses, different NDGDs lead to similar values of FA and D but different eigenvalues. However, different NDGDs at the voxel level provide varying values. The selection of the NDGD, therefore, should depend on the focus of different DTI applications.
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AJNR Am J Neuroradiol · Sep 2006
Case ReportsPercutaneous radio-frequency mandibular nerve rhizotomy guided by CT fluoroscopy.
We describe a new method for radio-frequency mandibular nerve rhizotomy under CT fluoroscopy. A patient with cancer had severe intractable and drug-resistant pain in his left mandibular region. ⋯ The needle was advanced to the mandibular nerve just caudal to the foramen ovale under real-time CT fluoroscopy, avoiding the cancer region. Pain scores of the patient were reduced after the nerve rhizotomy, without any complications.
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AJNR Am J Neuroradiol · Sep 2006
Relationship between variations in the circle of Willis and flow rates in internal carotid and basilar arteries determined by means of magnetic resonance imaging with semiautomated lumen segmentation: reference data from 125 healthy volunteers.
Volume flow rates in the feeding arteries of the brain are measured to evaluate blood flow dynamics in vascular disease. Although these flow values are thought to be effected by anatomic variations in the circle of Willis, few reports have described the effect. This study reports on the relationship between variations in the circle of Willis and volume flow rates in the bilateral internal carotid and basilar arteries of normal volunteers. ⋯ Variations in the circle of Willis correlate significantly with relative contributions by the flow rates of the bilateral internal carotid and basilar arteries.
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AJNR Am J Neuroradiol · Sep 2006
Subdural hematomas in infants with benign enlargement of the subarachnoid spaces are not pathognomonic for child abuse.
Patients who have benign enlargement of the subarachnoid spaces (BESS) have long been suspected of having an increased propensity for subdural hematomas either spontaneously or as a result of accidental injury. Subdural hematomas in infants are often equated with nonaccidental trauma (NAT). A better understanding of the clinical and imaging characteristics of subdural hematomas that occur either spontaneously or as a result of accidental trauma may help distinguish this group of patients from those who suffer subdural hematomas as a result of NAT. The purpose of this study is to describe the clinical and imaging characteristics of subdural hematomas that occur either spontaneously or as a result of accidental injury in infants with BESS. ⋯ Although suspicious for NAT, subdural hematomas can occur in children either spontaneously or as a result of accidental trauma. Caution must be exercised when investigating for NAT based on the sole presence of subdural hematomas, especially in children who are otherwise well and who have BESS.