Language pathway tracking: comparing nTMS-based DTI fiber tracking with a cubic ROIs-based protocol

2017 ◽  
Vol 126 (3) ◽  
pp. 1006-1014 ◽  
Author(s):  
Chiara Negwer ◽  
Nico Sollmann ◽  
Sebastian Ille ◽  
Theresa Hauck ◽  
Stefanie Maurer ◽  
...  
Keyword(s):  
Diffusion Tensor ◽  
Fiber Tracking ◽  
Subcortical Structures ◽  
Language Mapping ◽  
Glioma Surgery ◽  
Fiber Tracts ◽  
Uncinate Fascicle ◽  
Dti Fiber Tracking ◽  
Language Pathways ◽  
Diffusion Tensor Imaging Dti

OBJECTIVE Diffusion tensor imaging (DTI) fiber tracking (FT) has been widely used in glioma surgery in recent years. It can provide helpful information about subcortical structures, especially in patients with eloquent space-occupying lesions. This study compared the newly developed navigated transcranial magnetic stimulation (nTMS)-based DTI FT of language pathways with the most reproducible protocol for language pathway tractography, using cubic regions of interest (ROIs) for the arcuate fascicle. METHODS Thirty-seven patients with left-sided perisylvian lesions underwent language mapping by repetitive nTMS. DTI FT was performed using the cubic ROIs–based protocol and the authors' nTMS-based DTI FT approach. The same minimal fiber length and fractional anisotropy were chosen (50 mm and 0.2, respectively). Both protocols were performed with standard clinical tractography software. RESULTS Both methods visualized language-related fiber tracts (i.e., corticonuclear tract, arcuate fascicle, uncinate fascicle, superior longitudinal fascicle, inferior longitudinal fascicle, arcuate fibers, commissural fibers, corticothalamic fibers, and frontooccipital fascicle) in all 37 patients. Using the cubic ROIs-based protocol, 39.9% of these language-related fiber tracts were detected in the examined patients, as opposed to 76.0% when performing nTMS-based DTI FT. For specifically tracking the arcuate fascicle, however, the cubic ROIs-based approach showed better results (97.3% vs 75.7% with nTMS-based DTI FT). CONCLUSIONS The cubic ROIs-based protocol was designed for arcuate fascicle tractography, and this study shows that it is still useful for this intention. However, superior results were obtained using the nTMS-based DTI FT for visualization of other language-related fiber tracts.

scholarly journals Benefit of Action Naming Over Object Naming for Visualization of Subcortical Language Pathways in Navigated Transcranial Magnetic Stimulation-Based Diffusion Tensor Imaging-Fiber Tracking

2021 ◽  
Vol 15 ◽  
Author(s):  
Ann-Katrin Ohlerth ◽  
Roelien Bastiaanse ◽  
Chiara Negwer ◽  
Nico Sollmann ◽  
Severin Schramm ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Magnetic Stimulation ◽  
Diffusion Tensor ◽  
Fiber Tracking ◽  
Object Naming ◽  
Navigated Transcranial Magnetic Stimulation ◽  
Language Mapping ◽  
Action Naming ◽  
Dti Fiber Tracking ◽  
Language Pathways

Visualization of functionally significant subcortical white matter fibers is needed in neurosurgical procedures in order to avoid damage to the language network during resection. In an effort to achieve this, positive cortical points revealed during preoperative language mapping with navigated transcranial magnetic stimulation (nTMS) can be employed as regions of interest (ROIs) for diffusion tensor imaging (DTI) fiber tracking. However, the effect that the use of different language tasks has on nTMS mapping and subsequent DTI-fiber tracking remains unexplored. The visualization of ventral stream tracts with an assumed lexico-semantic role may especially benefit from ROIs delivered by the lexico-semantically demanding verb task, Action Naming. In a first step, bihemispheric nTMS language mapping was administered in 18 healthy participants using the standard task Object Naming and the novel task Action Naming to trigger verbs in a small sentence context. Cortical areas in which nTMS induced language errors were identified as language-positive cortical sites. In a second step, nTMS-based DTI-fiber tracking was conducted using solely these language-positive points as ROIs. The ability of the two tasks’ ROIs to visualize the dorsal tracts Arcuate Fascicle and Superior Longitudinal Fascicle, the ventral tracts Inferior Longitudinal Fascicle, Uncinate Fascicle, and Inferior Fronto-Occipital Fascicle, the speech-articulatory Cortico-Nuclear Tract, and interhemispheric commissural fibers was compared in both hemispheres. In the left hemisphere, ROIs of Action Naming led to a significantly higher fraction of overall visualized tracts, specifically in the ventral stream’s Inferior Fronto-Occipital and Inferior Longitudinal Fascicle. No difference was found between tracking with Action Naming vs. Object Naming seeds for dorsal stream tracts, neither for the speech-articulatory tract nor the inter-hemispheric connections. While the two tasks appeared equally demanding for phonological-articulatory processes, ROI seeding through the task Action Naming seemed to better visualize lexico-semantic tracts in the ventral stream. This distinction was not evident in the right hemisphere. However, the distribution of tracts exposed was, overall, mirrored relative to those in the left hemisphere network. In presurgical practice, mapping and tracking of language pathways may profit from these findings and should consider inclusion of the Action Naming task, particularly for lesions in ventral subcortical regions.

Quantifying accuracy and precision of diffusion MR tractography of the corticospinal tract in brain tumors

2014 ◽  
Vol 121 (2) ◽  
pp. 349-358 ◽  
Author(s):  
Maria Luisa Mandelli ◽  
Mitchel S. Berger ◽  
Monica Bucci ◽  
Jeffrey I. Berman ◽  
Bagrat Amirbekian ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Fiber Tracking ◽  
Subcortical White Matter ◽  
Motor Pathways ◽  
Motor Mapping ◽  
Fiber Tracts ◽  
Accuracy And Precision ◽  
Dti Fiber Tracking

Object The aim of this paper was to validate the diffusion tensor imaging (DTI) model for delineation of the corticospinal tract using cortical and subcortical white matter electrical stimulation for the location of functional motor pathways. Methods The authors compare probabilistic versus deterministic DTI fiber tracking by reconstructing the pyramidal fiber tracts on preoperatively acquired DTI in patients with brain tumors. They determined the accuracy and precision of these 2 methods using subcortical stimulation points and the sensitivity using cortical stimulation points. The authors further explored the reliability of these methods by estimation of the potential that the found connections were due to a random chance using a novel neighborhood permutation method. Results The probabilistic tracking method delineated tracts that were significantly closer to the stimulation points and was more sensitive than deterministic DTI fiber tracking to define the tracts directed to the motor sites. However, both techniques demonstrated poor sensitivity to finding lateral motor regions. Conclusions This study highlights the importance of the validation and quantification of preoperative fiber tracking with the aid of electrophysiological data during the surgery. The poor sensitivity of DTI to delineate lateral motor pathways reported herein suggests that DTI fiber tracking must be used with caution and only as adjunctive data to established methods for motor mapping.

Visualization of subcortical language pathways by diffusion tensor imaging fiber tracking based on rTMS language mapping

2016 ◽  
Vol 11 (3) ◽  
pp. 899-914 ◽  
Author(s):  
Chiara Negwer ◽  
Sebastian Ille ◽  
Theresa Hauck ◽  
Nico Sollmann ◽  
Stefanie Maurer ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Diffusion Tensor ◽  
Fiber Tracking ◽  
Language Mapping ◽  
Language Pathways

Pediatric navigated transcranial magnetic stimulation motor and language mapping combined with diffusion tensor imaging tractography: clinical experience

2020 ◽  
Vol 26 (5) ◽  
pp. 583-593
Author(s):  
Tizian Rosenstock ◽  
Thomas Picht ◽  
Heike Schneider ◽  
Peter Vajkoczy ◽  
Ulrich-Wilhelm Thomale
Keyword(s):  
Diffusion Tensor Imaging ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Surgical Planning ◽  
Diffusion Tensor ◽  
Fiber Tracking ◽  
Navigated Transcranial Magnetic Stimulation ◽  
Language Mapping ◽  
Eloquent Areas ◽  
Dti Fiber Tracking

OBJECTIVEIn adults, navigated transcranial magnetic stimulation (nTMS) has been established as a preoperative examination method for brain tumors in motor- and language-eloquent locations. However, the clinical relevance of nTMS in children with brain tumors is still unclear. Here, the authors present their initial experience with nTMS-based surgical planning and family counseling in pediatric cases.METHODSThe authors analyzed the feasibility of nTMS and its influence on counseling and surgical strategy in a prospective study conducted between July 2017 and September 2019. The main inclusion criterion was a potential benefit from functional mapping data derived from nTMS and/or nTMS-enhanced tractography in pediatric patients who presented to the authors’ department prior to surgery for lesions close to motor- and/or speech-eloquent areas. The study was undertaken in 14 patients (median age 7 years, 8 males) who presented with different brain lesions.RESULTSMotor mapping combined with cortical seed area definition could be performed in 10 children (71%) to identify the corticospinal tract by additional diffusion tensor imaging (DTI). All motor mappings could be performed successfully without inducing relevant side effects. In 7 children, nTMS language mapping was performed to detect language-relevant cortical areas and DTI fiber tractography was performed to visualize the individual language network. nTMS examination was not possible in 4 children because of lack of compliance (n = 2), syncope (n = 1), and preexisting implant (n = 1). After successful mapping, the spatial relation between lesion and functional tissue was used for surgical planning in all 10 patients, and 9 children underwent nTMS-DTI integrated neuronavigation. No surgical complications or unexpected neurological deterioration was observed. In all successful nTMS cases, better function-based counseling was offered to the families. In 6 of 10 patients the surgical strategy was adapted according to nTMS data, and in 6 of 10 cases the extent of resection (EOR) was redefined.CONCLUSIONSnTMS and DTI fiber tracking were feasible for the majority of children. Presurgical counseling as well as surgical planning for the approach and EOR were improved by the nTMS examination results. nTMS in combination with DTI fiber tracking can be regarded as beneficial for neurosurgical procedures in eloquent areas in the pediatric population.

Intraoperative Visualization of Fiber Tracking Based Reconstruction of Language Pathways in Glioma Surgery

Neurosurgery ◽  
2011 ◽  
Vol 70 (4) ◽  
pp. 911-920 ◽  
Author(s):  
Daniela Kuhnt ◽  
Miriam H. A. Bauer ◽  
Andreas Becker ◽  
Dorit Merhof ◽  
Amir Zolal ◽  
...  
Keyword(s):  
Diffusion Tensor ◽  
Tumor Resection ◽  
Fiber Tracking ◽  
Volumetric Analysis ◽  
Fiber Tractography ◽  
Glioma Surgery ◽  
Neuroepithelial Tumors ◽  
Volumetric Assessment ◽  
Language Pathways ◽  
Intraoperative Visualization

Abstract BACKGROUND: For neuroepithelial tumors, the surgical goal is maximum resection with preservation of neurological function. This is contributed to by intraoperative magnetic resonance imaging (iMRI) combined with multimodal navigation. OBJECTIVE: We evaluated the contribution of diffusion tensor imaging (DTI)-based fiber tracking of language pathways with 2 different algorithms (tensor deflection, connectivity analysis [CA]) integrated in the navigation on the surgical outcome. METHODS: We evaluated 32 patients with neuroepithelial tumors who underwent surgery with DTI-based fiber tracking of language pathways integrated in neuronavigation. The tensor deflection algorithm was routinely used and its results intraoperatively displayed in all cases. The CA algorithm was furthermore evaluated in 23 cases. Volumetric assessment was performed in pre- and intraoperative MR images. To evaluate the benefit of fiber tractography, language deficits were evaluated pre- and postoperatively and compared with the volumetric analysis. RESULTS: Final gross-total resection was performed in 40.6% of patients. Absolute tumor volume was reduced from 55.33 ± 63.77 cm3 to 20.61 ± 21.67 cm3 in first iMRI resection control, to finally 11.56 ± 21.92 cm3 (P < .01). Fiber tracking of the 2 algorithms showed a deviation of the displayed 3D objects by <5 mm. In long-term follow-up only 1 patient (3.1%) had a persistent language deficit. CONCLUSION: Intraoperative visualization of language-related cortical areas and the connecting pathways with DTI-based fiber tracking can be successfully performed and integrated in the navigation system. In a setting of intraoperative high-field MRI this contributes to maximum tumor resection with low postoperative morbidity.

scholarly journals Distinct approaches to language pathway tractography: comparison of anatomy-based, repetitive navigated transcranial magnetic stimulation (rTMS)–based, and rTMS-enhanced diffusion tensor imaging–fiber tracking

2021 ◽  
pp. 1-12
Author(s):  
Luca L. Silva ◽  
Mehmet S. Tuncer ◽  
Peter Vajkoczy ◽  
Thomas Picht ◽  
Tizian Rosenstock
Keyword(s):  
Diffusion Tensor Imaging ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Clinical Utility ◽  
Surgical Planning ◽  
Diffusion Tensor ◽  
Fiber Tracking ◽  
Navigated Transcranial Magnetic Stimulation ◽  
Language Mapping ◽  
Language Pathways

OBJECTIVE Visualization of subcortical language pathways by means of diffusion tensor imaging–fiber tracking (DTI-FT) is evolving as an important tool for surgical planning and decision making in patients with language-suspect brain tumors. Repetitive navigated transcranial magnetic stimulation (rTMS) cortical language mapping noninvasively provides additional functional information. Efforts to incorporate rTMS data into DTI-FT are promising, but the lack of established protocols makes it hard to assess clinical utility. The authors performed DTI-FT of important language pathways by using five distinct approaches in an effort to evaluate the respective clinical usefulness of each approach. METHODS Thirty patients with left-hemispheric perisylvian lesions underwent preoperative rTMS language mapping and DTI. FT of the principal language tracts was conducted according to different strategies: Ia, anatomical landmark based; Ib, lesion-focused landmark based; IIa, rTMS based; IIb, rTMS based with postprocessing; and III, rTMS enhanced (based on a combination of structural and functional data). The authors analyzed the respective success of each method in revealing streamlines and conducted a multinational survey with expert clinicians to evaluate aspects of clinical utility. RESULTS The authors observed high usefulness and accuracy ratings for anatomy-based approaches (Ia and Ib). Postprocessing of rTMS-based tractograms (IIb) led to more balanced perceived information content but did not improve the usefulness for surgical planning and risk assessment. Landmark-based tractography (Ia and Ib) was most successful in delineating major language tracts (98% success), whereas rTMS-based tractography (IIa and IIb) frequently failed to reveal streamlines and provided less complete tractograms than the landmark-based approach (p < 0.001). The lesion-focused landmark-based (Ib) and the rTMS-enhanced (III) approaches were the most preferred methods. CONCLUSIONS The lesion-focused landmark-based approach (Ib) achieved the best ratings and enabled visualization of the principal language tracts in almost all cases. The rTMS-enhanced approach (III) was positively evaluated by the experts because it can reveal cortico-subcortical connections, but the functional relevance of these connections is still unclear. The use of regions of interest derived solely from cortical rTMS mapping (IIa and IIb) leads to cluttered images that are of limited use in clinical practice.

scholarly journals Quantitative diffusion tensor MRI-based fiber tracking of human skeletal muscle

2007 ◽  
Vol 103 (2) ◽  
pp. 673-681 ◽  
Author(s):  
Drew A. Lansdown ◽  
Zhaohua Ding ◽  
Megan Wadington ◽  
Jennifer L. Hornberger ◽  
Bruce M. Damon
Keyword(s):  
Muscle Fiber ◽  
Diffusion Tensor ◽  
Fiber Tracking ◽  
Laboratory Frame ◽  
Mean Value ◽  
Pennation Angle ◽  
Frame Of Reference ◽  
Fiber Tracts ◽  
Angle Measurements ◽  
The Mean

Diffusion-tensor magnetic resonance imaging (DT-MRI) offers great potential for understanding structure-function relationships in human skeletal muscles. The purposes of this study were to demonstrate the feasibility of using in vivo human DT-MRI fiber tracking data for making pennation angle measurements and to test the hypothesis that heterogeneity in the orientation of the tibialis anterior (TA) muscle's aponeurosis would lead to heterogeneity in pennation angle. Eight healthy subjects (5 male) were studied. T1-weighted anatomical MRI and DT-MRI data were acquired of the TA muscle. Fibers were tracked from the TA's aponeurosis by following the principal eigenvector. The orientations of the aponeurosis and muscle fiber tracts in the laboratory frame of reference and the orientation of the fiber tracts with respect to the aponeurosis [i.e., the pennation angle (θ)] were determined. The muscle fiber orientations, when expressed relative to the laboratory frame of reference, did not change as functions of superior-to-inferior position. The sagittal and coronal orientations of the aponeurosis did not change in practically significant manners either, but the aponeurosis′ axial orientation changed by ∼40°. As a result, the mean value for θ decreased from 16.3 (SD 6.9) to 11.4° (SD 5.0) along the muscle's superior-to-inferior direction. The mean value of θ was greater in the deep than in the superficial compartment. We conclude that pennation angle measurements of human muscle made using DT-MRI muscle fiber tracking are feasible and reveal that in the foot-head direction, there is heterogeneity in the pennation properties of the human TA muscle.

scholarly journals Contemporary intraoperative visualization for GBM with use of exoscope, 5-ALA fluorescence-guided surgery and tractography

2022 ◽  
Vol 6 (1) ◽  
pp. V5
Keyword(s):  
Diffusion Tensor ◽  
High Grade Glioma ◽  
Brain Regions ◽  
High Grade ◽  
Glioma Surgery ◽  
Guided Surgery ◽  
Word Finding ◽  
Patient Consent ◽  
Dti Fiber Tracking ◽  
Intraoperative Visualization

Maximal safe resection is the primary goal of glioma surgery. By incorporating improved intraoperative visualization with the 3D exoscope combined with 5-ALA fluorescence, in addition to neuronavigation and diffusion tensor imaging (DTI) fiber tracking, the safety of resection of tumors in eloquent brain regions can be maximized. This video highlights some of the various intraoperative adjuncts used in brain tumor surgery for high-grade glioma. In this case, the authors highlight the resection of a left posterior temporal lobe high-grade glioma in a 33-year-old patient, who initially presented with seizures, word-finding difficulty, and right-sided weakness. They demonstrate the multiple surgical adjuncts used both before and during surgical resection, and how multiple adjuncts can be effectively orchestrated to make surgery in eloquent brain areas safer for patients. Patient consent was obtained for publication. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21174

COMPREHENSIVE 3D FIBER TRACKING AS A NEW VISUALIZATION SYSTEM IN BRAIN STUDIES

2007 ◽  
Vol 07 (04) ◽  
pp. 749-765 ◽  
Author(s):  
DANMARY SANCHEZ ◽  
MALEK ADJOUADI ◽  
NOLAN R. ALTMAN ◽  
DANIEL SANCHEZ ◽  
BYRON BERNAL
Keyword(s):  
Diffusion Tensor ◽  
3D Visualization ◽  
Fiber Tracking ◽  
Brain Images ◽  
Visualization System ◽  
Fiber Tracts ◽  
Desirable Outcome ◽  
White Matter Fiber Tracts ◽  
Magnetic Resonance Imaging Mri ◽  
Using Data

Comprehensive spatial visualization of fiber tracts from all perspectives is a highly desirable outcome in brain studies. To achieve this aim, this study establishes the foundation for a new 3D visual interface that integrates Magnetic Resonance Imaging (MRI) to Diffusion Tensor Imaging (DTI). The need for such an interface is critical for understanding brain dynamics, and for providing accurate diagnosis of key brain dysfunctions, in terms of neuronal connectivity in the human brain. Two research fronts were explored: (1) the development of new image processing techniques resulting in comprehensive visualization mechanisms that accurately establish relational positioning of neuronal fiber tracts and key landmarks in semi-transparent 3D brain images, and (2) the design of key algorithms that do not tax the computational requirements of 3D rendering and feature extraction using 2D MRI and DTI frames, remaining within practical time constraints. The system was evaluated using data from thirty patients and volunteers with the Brain Institute at Miami Children's Hospital. The highly integrated and fully embedded fiber-tracking software system provides an optimal research environment for innovative visualization mechanisms of white matter fiber tracts. This 3D visualization system reached the implementation level that makes it ready for deployment at other clinical sites.

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