Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Case Reports
Angiographic perfusion imaging: real-time assessment of endovascular treatment for cerebral vasospasm.
Cerebral perfusion analysis is useful in the diagnosis and treatment of cerebral vasospasm. A new modality of real-time cerebral perfusion imaging and analysis has been developed using standard 2-dimensional angiography. We report our initial experience with this technique to assess response to therapy during endovascular vasospasm procedures. ⋯ Real-time angiographic perfusion imaging is feasible during endovascular procedures for vasospasm. Perfusion analysis may aid in assessment of efficacy of the intervention. Comparison with traditional perfusion imaging is needed to validate this technique.
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The authors describe a case of a proatlantal intersegmental artery seen in the setting of external carotid artery dissection and subclavian steal due to proximal subclavian artery stenosis. ⋯ This case represents an interesting presentation of both subclavian steal and an external carotid artery to VA anastomosis. Also, the presence of a dissection of the external carotid artery represents a rare finding.
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Beta-ketothiolase (BKT) deficiency is a rare autosomal recessive metabolic disorder, which causes episodic severe metabolic acidosis. Average onset of disease is from 6 to 24 months. ⋯ We report a case of a 5-year-old girl with BKT deficiency with isolated focal T2 hyperintensities involving the globi pallidi, which demonstrated restricted diffusion. To our knowledge, these imaging findings have not been previously reported in the setting of BKT deficiency.
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Artery-to-artery embolism generally occurs in patients with not only moderate to severe arterial stenosis but also plaque vulnerability. Two unique cases with free-floating thrombi at the distal side of the small plaque in the internal carotid artery without stenosis are presented and its clinical implications are discussed. ⋯ In these two cases, duplex ultrasonography revealed free-floating thrombi developed at the distal region of small plaques. Aggressive treatment should be considered in a patient with thromboembolic stroke who has the small plaque presenting "snake fang" sign even if there is no stenosis or plaque vulnerability.
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Real-time fMRI is especially vulnerable to task-correlated movement artifacts because statistical methods normally available in conventional analyses to remove such signals cannot be used in the context of real-time fMRI. Multi-voxel classifier-based methods, although advantageous in many respects, are particularly sensitive. Here we systematically studied various movements of the head and face to determine to what extent these can "masquerade" as signal in multi-voxel classifiers. ⋯ Movement tasks of many types (including movements of the eyes, face, and body) can lead to false positives in classifier-based real-time fMRI paradigms.