Neuroimaging clinics of North America
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Neuroimaging Clin. N. Am. · Nov 2014
ReviewDiffusion tensor imaging for brain malformations: does it help?
In this article, the basics of diffusion-weighted imaging/diffusion tensor imaging (DTI) are discussed, including a short historical perspective on the fiber dissection technique, followed by a review of selected brain malformations in which DTI and tractography have contributed to a better understanding of the malformations, and by a clinical case in which DTI showed a disorder of the internal neuroarchitecture that could not be correctly appreciated by conventional anatomic magnetic resonance imaging.
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Neuroimaging Clin. N. Am. · Nov 2014
ReviewTechnical considerations for functional magnetic resonance imaging analysis.
Clinical application of functional magnetic resonance imaging (fMRI) based on blood oxygenation level-dependent (BOLD) effect has increased over the past decade because of its ability to map regional blood flow in response to brain stimulation. This mapping is primarily achieved by exploiting the BOLD effect precipitated by changes in the magnetic properties of hemoglobin. ⋯ Conventional echo planar imaging techniques are used to acquire stimulus-driven fMR imaging BOLD data. This article highlights technical aspects of fMRI data analysis to make it more accessible in clinical settings.
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Neuroimaging Clin. N. Am. · Nov 2014
ReviewApplications of blood-oxygen-level-dependent functional magnetic resonance imaging and diffusion tensor imaging in epilepsy.
The lifetime prevalence of epilepsy ranges from 2.7 to 12.4 per 1000 in Western countries. Around 30% of patients with epilepsy remain refractory to antiepileptic drugs and continue to have seizures. Noninvasive imaging techniques such as functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) have helped to better understand mechanisms of seizure generation and propagation, and to localize epileptic, eloquent, and cognitive networks. In this review, the clinical applications of fMRI and DTI are discussed, for mapping cognitive and epileptic networks and organization of white matter tracts in individuals with epilepsy.
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Neuroimaging Clin. N. Am. · Nov 2014
ReviewBlood oxygen level dependent functional magnetic resonance imaging for presurgical planning.
Functional magnetic resonance imaging (fMRI) has become a common tool for presurgical sensorimotor mapping, and is a significant preoperative asset for tumors located adjacent to the central sulcus. fMRI has changed surgical options for many patients. This noninvasive tool allows for easy display and integration with other neuroimaging techniques. ⋯ Tumors that affect the normal vascular coupling of neuronal activity will affect fMRI measurements. This article discusses the usefulness of blood oxygen level dependent (BOLD) fMRI with regard to preoperative motor mapping.
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Neuroimaging Clin. N. Am. · Nov 2014
ReviewMemory assessment in the clinical context using functional magnetic resonance imaging: a critical look at the state of the field.
The use of functional magnetic resonance imaging to map language and sensorimotor regions in the brain is rapidly becoming a clinical standard in neurosurgical centers. Despite a wealth of cognitive neuroscience data showing focal medial temporal activation elicited by memory encoding and retrieval tasks in controls, translating such findings to generate reliable metrics for clinical use has been slow. The current review documents some of the successes that have been achieved, using both activation and resting-state functional connectivity in the clinical context of temporal lobe epilepsy, and discusses some of the challenges that remain to be addressed.