A Detailed Analysis of Functional Magnetic Resonance Imaging in the Frontal Language Area: A Comparative Study With Extraoperative Electrocortical Stimulation

Neurosurgery ◽  
2011 ◽  
Vol 69 (3) ◽  
pp. 590-597 ◽  
Author(s):  
Naoto Kunii ◽  
Kyousuke Kamada ◽  
Takahiro Ota ◽  
Kensuke Kawai ◽  
Nobuhito Saito
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Detailed Analysis ◽  
Sensitivity And Specificity ◽  
Picture Naming ◽  
Z Score ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Eloquent Areas

Abstract BACKGROUND: Functional magnetic resonance imaging (fMRI) is a less invasive way of mapping brain functions. The reliability of fMRI for localizing language-related function is yet to be determined. OBJECTIVE: We performed a detailed analysis of language fMRI reliability by comparing the results of 3-T fMRI with maps determined by extraoperative electrocortical stimulation (ECS). METHODS: This study was performed on 8 epileptic patients who underwent subdural electrode placement. The tasks performed during fMRI included verb generation, abstract/concrete categorization, and picture naming. We focused on the frontal lobe, which was effectively activated by these tasks. In extraoperative ECS, 4 tasks were combined to determine the eloquent areas: spontaneous speech, picture naming, reading, and comprehension. We calculated the sensitivity and specificity with different Z score thresholds for each task and appropriate matching criteria. For further analysis, we divided the frontal lobe into 5 areas and investigated intergyrus variations in sensitivity and specificity. RESULTS: The abstract/concrete categorization task was the most sensitive and specific task in fMRI, whereas the picture naming task detected eloquent areas most efficiently in ECS. The combination of the abstract/concrete categorization task and a 3-mm matching criterion gave the best tradeoff (sensitivity, 83%; specificity, 61%) when the Z score was 2.24. As for intergyrus variation, the posterior inferior frontal gyrus showed the best tradeoff (sensitivity, 91%; specificity, 59%), whereas the anterior middle frontal gyrus had low specificity. CONCLUSION: Despite different tasks for fMRI and extraoperative ECS, the relatively low specificity might be caused by a fundamental discrepancy between the 2 techniques. Reliability of language fMRI activation might differ, depending on the brain region.

scholarly journals Funkciono MR snimanje u detekciji elokventnih mozdanih zona

2007 ◽  
Vol 54 (3) ◽  
pp. 39-41 ◽  
Author(s):  
O.B. Sveljo ◽  
K.M. Koprivek ◽  
M.A. Lucic ◽  
Z. Markovic ◽  
M. Prvulovic
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Spatial Resolution ◽  
Gold Standard ◽  
The Other ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Eloquent Areas ◽  
The Brain

Functional magnetic resonance imaging - fMRI is a relative new magnetic resonance technique that may be used for identification of eloquent cortical areas. Gold standard for detection of eloquent areas that should be preserved subsequent to resection is a direct cortical stimulation, which is invasive and frequently difficult to be performed. On the other hand, fMRI has proved to be a promising alternative with good time and spatial resolution. The paper explains the method of the functional MR imagining, origins of the signal and its relation to the neuronal activation. fMRI technique is illustrated by the example of the motor cortex identification. Functional Magnetic Resonance Imaging - fMRI is a relatively new MR application that can be used for detection of eloquent areas of the brain. The gold standard for identifying eloquent areas of the brain to be avoided in resections is direct cortical stimulation, which is an invasive and difficult procedure. On the other hand fMRI shows great promise as noninvasive alternative to invasive brain mapping with good temporal and spatial resolution. This paper introduces the technique of fMRI, explain the origin of the signal and his connections with neural activations. An illustrative example of a motor activation study is described.

scholarly journals Tongue Posture, Tongue Movements, Swallowing, and Cerebral Areas Activation: A Functional Magnetic Resonance Imaging Study

2020 ◽  
Vol 10 (17) ◽  
pp. 6027 ◽  
Author(s):  
Fabio Scoppa ◽  
Sabina Saccomanno ◽  
Gianluca Bianco ◽  
Alessio Pirino
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Precentral Gyrus ◽  
Z Score ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Tongue Protrusion ◽  
Postcentral Gyrus ◽  
Parietal Lobule

The aim of this study was to pinpoint the cerebral regions implicated during swallowing by comparing the brain activation areas associated with two different volitional movements: tongue protrusion and tongue elevation. Twenty-four healthy subjects (11—males 22 ± 2.9 y; 13—females 23 ± 4.1 y; were examined through functional magnetic resonance imaging (fMRI) while performing two different swallowing tasks: with tongue protrusion and with tongue elevation. The study was carried out with the help of fMRI imaging which assesses brain signals caused by changes in neuronal activity in response to sensory, motor or cognitive tasks. The precentral gyrus and the cerebellum were activated during both swallowing tasks while the postcentral gyrus, thalamus, and superior parietal lobule could be identified as large activation foci only during the protrusion task. During protrusion tasks, increased activations were also seen in the left-middle and medial frontal gyrus, right thalamus, inferior parietal lobule, and the superior temporal gyrus (15,592-voxels; Z-score 5.49 ± 0.90). Tongue elevation activated a large volume of cortex portions within the left sub-gyral cortex and minor activations in both right and left inferior parietal lobules, right postcentral gyrus, lentiform nucleus, subcortical structures, the anterior cingulate, and left insular cortex (3601-voxels; Z-score 5.23 ± 0.52). However, the overall activation during swallowing tasks with tongue elevation, was significantly less than swallowing tasks with tongue protrusion. These results suggest that tongue protrusion (on inferior incisors) during swallowing activates a widely distributed network of cortical and subcortical areas than tongue elevation (on incisor papilla), suggesting a less economic and physiologically more complex movement. These neuromuscular patterns of the tongue confirm the different purpose of elevation and protrusion during swallowing and might help professionals manage malocclusions and orofacial myofunctional disorders.

scholarly journals Surgical resection of low-grade gliomas in eloquent areas with the guidance of the preoperative functional magnetic resonance imaging and craniometric points

2016 ◽  
Vol 7 (04) ◽  
pp. 571-576 ◽  
Author(s):  
Ahmed Abdullah ◽  
Hisham El Shitany ◽  
Waleed Abbass ◽  
Amr Safwat ◽  
Amr K Elsamman ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Surgical Resection ◽  
Awake Craniotomy ◽  
Low Grade ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Low Grade Gliomas ◽  
Eloquent Areas

ABSTRACT Objectives: Surgical resection of low-grade gliomas (LGGs) in eloquent areas is one of the challenges in neurosurgery, using assistant tools to facilitate effective excision with minimal postoperative neurological deficits has been previously discussed (awake craniotomy and intraoperative cortical stimulation); however, these tools could have their own limitations thus implementation of a simple and effective technique that can guide to safe excision is needed in many situations. Materials and Methods: The authors conducted a retrospective analysis of a prospectively collected data of 76 consecutive surgical cases of LGGs of these 21 cases were situated in eloquent areas. Preoperative functional magnetic resonance imaging (fMRI), pre- and post-operative MRI with volumetric analysis of the tumor size was conducted, and intraoperative determination of the craniometric points related to the tumor (navigation guided in 10 cases) were studied to evaluate the effectiveness of the aforementioned tools in safe excision of the aforementioned tumors. Results: Total-near total excision in 14 (66.67%) subtotal in 6 (28.57%), and biopsy in 1 case (4.57%). In long-term follow–up, only one case experienced persistent dysphasia. Conclusion: In spite of its simplicity, the identification of the safe anatomical landmarks guided by the preoperative fMRI is a useful technique that serves in safe excision of LGGs in eloquent areas. Such technique can replace intraoperative evoked potentials or the awake craniotomy in most of the cases. However, navigation-guided excision might be crucial in deeply seated and large tumors to allow safe and radical excision.

Functional Magnetic Resonance Imaging Measures of Blood Flow Patterns in the Human Auditory Cortex in Response to Sound

1998 ◽  
Vol 41 (3) ◽  
pp. 538-548 ◽  
Author(s):  
Sean C. Huckins ◽  
Christopher W. Turner ◽  
Karen A. Doherty ◽  
Michael M. Fonte ◽  
Nikolaus M. Szeverenyi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Speech Stimuli ◽  
Complex Stimuli ◽  
Scanning Session ◽  
Auditory Research

Functional Magnetic Resonance Imaging (fMRI) holds exciting potential as a research and clinical tool for exploring the human auditory system. This noninvasive technique allows the measurement of discrete changes in cerebral cortical blood flow in response to sensory stimuli, allowing determination of precise neuroanatomical locations of the underlying brain parenchymal activity. Application of fMRI in auditory research, however, has been limited. One problem is that fMRI utilizing echo-planar imaging technology (EPI) generates intense noise that could potentially affect the results of auditory experiments. Also, issues relating to the reliability of fMRI for listeners with normal hearing need to be resolved before this technique can be used to study listeners with hearing loss. This preliminary study examines the feasibility of using fMRI in auditory research by performing a simple set of experiments to test the reliability of scanning parameters that use a high resolution and high signal-to-noise ratio unlike that presently reported in the literature. We used consonant-vowel (CV) speech stimuli to investigate whether or not we could observe reproducible and consistent changes in cortical blood flow in listeners during a single scanning session, across more than one scanning session, and in more than one listener. In addition, we wanted to determine if there were differences between CV speech and nonspeech complex stimuli across listeners. Our study shows reproducibility within and across listeners for CV speech stimuli. Results were reproducible for CV speech stimuli within fMRI scanning sessions for 5 out of 9 listeners and were reproducible for 6 out of 8 listeners across fMRI scanning sessions. Results of nonspeech complex stimuli across listeners showed activity in 4 out of 9 individuals tested.

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