Articles: neuronavigation.
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Acta neurochirurgica · Apr 2004
Clinical TrialCourse of brain shift during microsurgical resection of supratentorial cerebral lesions: limits of conventional neuronavigation.
The authors have conducted a prospective study to evaluate the amount and course of brain shift during microsurgical removal of supratentorial cerebral lesions, and to assess factors which potentially influence these shifts. ⋯ The data demonstrate the dynamics of brain shift and the limits of conventional neuronavigation and add additional support for the unavoidable inaccuracy of contemporary neuronavigational systems once the cranium is opened. Brain shift leads to a significant loss of reliability of neuronavigation systems during microsurgical removal of intracranial lesions and there are differences of the course and the amount of brain shift in relation to special subgroups of supratentorial cerebral lesions. However, because of the heterogeneous nature of lesions neurosurgeons have to remove, the modest quantity of shared common variance, and the differences between superficial and subcortical brain shift, it seems unlikely that the amount and course of brain shift become exactly predictable pre-operatively. Only an intra-operative update of image data should have the capacity to overcome this fundamental problem of modern neuronavigation.
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Minim Invas Neurosur · Oct 2003
Case ReportsTechnical refinements for validating functional MRI-based neuronavigation data by electrical stimulation during cortical language mapping.
Preoperative functional neuroimaging techniques represent an appealing method to localize language areas in tumor surgery, but their reliability still needs to be confirmed by accurate comparison with more invasive but validated mapping techniques like intraoperative electrical cortical stimulation. Two patients harboring a glioma involving speech areas underwent mapping of language function by preoperative functional magnetic resonance imaging (fMRI), whose results were integrated into the neuronavigation device, and by intraoperative electrical stimulation mapping (ESM). The utilization of neuronavigation allowed us to estimate the degree of spatial correspondence between language areas detected by the two techniques. ⋯ It was possible to achieve a gross total tumor removal while respecting language areas in both cases, with no permanent postoperative phasic aggravation. The concordance of results between pre- and intraoperative mapping techniques in our patients indicates that preoperative fMRI language mapping may prove useful when planning the resection of intracerebral lesions in language areas. However, accurate neurofunctional imaging protocols and image analysis are crucial to obtain a preoperative language mapping that is in agreement with ESM findings.
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Zhonghua Wai Ke Za Zhi · Sep 2003
Randomized Controlled Trial Clinical Trial[Role of diffusion tensor imaging in neuronavigation surgery of brain tumors involving pyramidal tracts].
To explore the role of diffusion tensor imaging (DTI) in neuronavigation surgery of brain tumors involving pyramidal tracts. ⋯ DTI allows individual estimation of large fiber tracts of brain. Furthermore, to integrate spatial three-dimensional information concerning the white matter tracts into traditional neuronavigation images during surgery, was valuable in presenting topographical character of involving (shift or erosive) pyramidal tracts and relationship with the margins of neighboring tumors. The mapping of large fiber tracts was a safe, efficient, reliable technique. DTI should be routinely used in neuronavigation surgery of brain tumor involving pyramidal tracts to plan the optimal trajectory and ensure total resection of the lesions during operation, as well as to decrease potential disability after operation and to shorten the length of hospitalization.
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In recent years, surgical navigation systems have become equipped to allow incorporation of data such as functional neuronavigation data. Functional magnetic resonance (fMR) imaging is a noninvasive modality that demonstrates various brain functions. ⋯ One advantage is that it can be implemented in presurgical imaging protocols and is therefore potentially widely available in general neurosurgical practice. In this paper the integration of fMR imaging and surgical navigation is described, and the potential advantages and pitfalls of its application in clinical practice are discussed.
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The aim of this study was to analyze the usefulness of preoperative language functional magnetic resonance imaging (fMRI), by correlating fMRI data with intraoperative cortical stimulation results for patients with brain tumors. ⋯ With the paradigms and analysis thresholds used in this study, language fMRI data obtained with naming or verb generation tasks, before and after surgery, were imperfectly correlated with intraoperative brain mapping results. A better correlation could be obtained by combining the fMRI tasks. The overall results of this study demonstrated that language fMRI could not be used to make critical surgical decisions in the absence of direct brain mapping. Other acquisition protocols are required for evaluation of the potential role of language fMRI in the accurate detection of essential cortical language areas.