Cortical mapping and frameless stereotactic navigation in the high-field intraoperative magnetic resonance imaging suite

Frameless stereotactic neuronavigation provides tracking of surgical instruments on radiographic images and orients the surgeon to tumor margins at surgery. Bipolar electrical stimulation mapping (ESM) delineates safe limits for resection of brain tumors adjacent to eloquent cortex. These standard techniques could complement the capability of intraoperative MR (iMR) imaging to evaluate for occult residual disease during surgery and promote more complete tumor removal. The use of frameless neuronavigation in the high-field iMR imaging suite requires that a few pieces of standard equipment be replaced by nonferromagnetic instruments. Specific use of ESM in a high-field iMR imaging suite has not been reported in the literature. To study whether frameless neuronavigation and electrical stimulation mapping could be successfully integrated in the high-field iMR imaging suite, the authors employed these modalities in 10 consecutive cases involving patients undergoing conscious craniotomy for primary brain tumors located in or adjacent to eloquent cortices. Equipment included a custom high-field MR imaging–compatible head holder and dynamic reference frame attachment, a standard MR imaging–compatible dynamic reference frame, a standard MR imaging machine with a table top that could be translated to a pedestal outside the 5-gauss line for the operative intervention, and standard neuronavigational and cortical stimulation equipment. Both ESM and frameless stereotactic guidance were performed outside the 5-gauss line. The presence of residual neoplasm was evaluated using iMR imaging; resection was continued until eloquent areas were encountered or iMR imaging confirmed complete removal of any residual tumor. Mapping identified essential language (5 patients), sensory (6), and motor (7) areas. The combined use of frameless stereotactic navigation, ESM, and iMR imaging resulted in complete radiographic resection in 7 cases and resection to an eloquent margin in 3 cases. Postoperative MR imaging confirmed final iMR imaging findings. No patient experienced a permanent new neurological deficit. Familiar techniques such as frameless navigation and ESM can be rapidly, inexpensively, safely, and effectively integrated into the high-field iMR imaging suite.

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Diffusion Tensor and Perfusion Imaging of Brain Tumors in High-Field MR Imaging

Neuroimaging Clinics of North America ◽

10.1016/j.nic.2012.02.001 ◽

2012 ◽

Vol 22 (2) ◽

pp. 123-134 ◽

Cited By ~ 26

Author(s):

Seung-Koo Lee

Keyword(s):

Brain Tumors ◽

Mr Imaging ◽

Perfusion Imaging ◽

High Field ◽

Diffusion Tensor ◽

High Field Mr

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Preoperative Functional MR Imaging Localization of Language and Motor Areas: Effect on Therapeutic Decision Making in Patients with Potentially Resectable Brain Tumors

Yearbook of Neurology and Neurosurgery ◽

10.1016/s0513-5117(08)70112-1 ◽

2007 ◽

Vol 2007 ◽

pp. 159-160

Author(s):

B.C. Bowen

Keyword(s):

Decision Making ◽

Brain Tumors ◽

Mr Imaging ◽

Therapeutic Decision ◽

Functional Mr Imaging ◽

Therapeutic Decision Making ◽

Motor Areas

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Evaluation of Early Microstructural Changes in the R6/1 Mouse Model of Huntington's Disease by Ultra-High Field Diffusion MR Imaging

Neurobiology of Aging ◽

10.1016/j.neurobiolaging.2021.02.006 ◽

2021 ◽

Author(s):

Rodolfo G. Gatto ◽

Carina Weissmann ◽

Manish Amin ◽

Quetzalli D. Angeles-López ◽

Lucia García-Lara ◽

...

Keyword(s):

Mr Imaging ◽

Mouse Model ◽

Huntington's Disease ◽

Huntington’S Disease ◽

High Field ◽

Ultra High Field ◽

Microstructural Changes ◽

Diffusion Mr ◽

Field Diffusion ◽

Diffusion Mr Imaging

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Functional MR Imaging of the Cervical Spinal Cord by Use of Electrical Stimulation at LI4 (Hegu)

2006 International Conference of the IEEE Engineering in Medicine and Biology Society ◽

10.1109/iembs.2006.260591 ◽

2006 ◽

Cited By ~ 5

Author(s):

W.D. Wang ◽

K.M. Kong ◽

Y.Y. Xiao ◽

X.J. Wang ◽

B. Liang ◽

...

Keyword(s):

Spinal Cord ◽

Electrical Stimulation ◽

Mr Imaging ◽

Cervical Spinal Cord ◽

Functional Mr Imaging

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Integrated positron emission tomography and magnetic resonance imaging–guided resection of brain tumors: a report of 103 consecutive procedures

Journal of Neurosurgery ◽

10.3171/jns.2006.104.2.238 ◽

2006 ◽

Vol 104 (2) ◽

pp. 238-253 ◽

Cited By ~ 102

Author(s):

Benoît Pirotte ◽

Serge Goldman ◽

Olivier Dewitte ◽

Nicolas Massager ◽

David Wikler ◽

...

Keyword(s):

Positron Emission Tomography ◽

Brain Tumors ◽

Mr Imaging ◽

Tumor Resection ◽

Tracer Uptake ◽

Emission Tomography ◽

Mr Images ◽

Pet Tracer ◽

Positron Emission ◽

Pet Scanning

Object The aim of this study was to evaluate the integration of positron emission tomography (PET) scanning data into the image-guided resection of brain tumors. Methods Positron emission tomography scans obtained using fluorine-18 fluorodeoxyglucose (FDG) and l-[methyl-11C]methionine (MET) were combined with magnetic resonance (MR) images in the navigational planning of 103 resections of brain tumors (63 low-grade gliomas [LGGs] and 40 high-grade gliomas [HGGs]). These procedures were performed in 91 patients (57 males and 34 females) in whom tumor boundaries could not be accurately identified on MR images for navigation-based resection. The level and distribution of PET tracer uptake in the tumor were analyzed to define the lesion contours, which in turn yielded a PET volume. The PET scanning–demonstrated lesion volume was subsequently projected onto MR images and compared with MR imaging data (MR volume) to define a final target volume for navigation-based resection—the tumor contours were displayed in the microscope’s eyepiece. Maximal tumor resection was accomplished in each case, with the intention of removing the entire area of abnormal metabolic activity visualized during surgical planning. Early postoperative MR imaging and PET scanning studies were performed to assess the quality of tumor resection. Both pre- and postoperative analyses of MR and PET images revealed whether integrating PET data into the navigational planning contributed to improved tumor volume definition and tumor resection. Metabolic information on tumor heterogeneity or extent was useful in planning the surgery. In 83 (80%) of 103 procedures, PET studies contributed to defining a final target volume different from that obtained with MR imaging alone. Furthermore, FDG-PET scanning, which was performed in a majority of HGG cases, showed that PET volume was less extended than the MR volume in 16 of 21 cases and contributed to targeting the resection to the hypermetabolic (anaplastic) area in 11 (69%) of 16 cases. Performed in 59 LGG cases and 23 HGG cases, MET-PET demonstrated that the PET volume did not match the MR volume and improved the tumor volume definition in 52 (88%) of 59 and 18 (78%) of 23, respectively. Total resection of the area of increased PET tracer uptake was achieved in 54 (52%) of 103 procedures. Conclusions Imaging guidance with PET scanning provided independent and complementary information that helped to assess tumor extent and plan tumor resection better than with MR imaging guidance alone. The PET scanning guidance could help increase the amount of tumor removed and target image-guided resection to tumor portions that represent the highest evolving potential.

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Early changes measured by magnetic resonance imaging in cerebral blood flow, blood volume, and blood-brain barrier permeability following dexamethasone treatment in patients with brain tumors

Journal of Neurosurgery ◽

10.3171/jns.1999.90.2.0300 ◽

1999 ◽

Vol 90 (2) ◽

pp. 300-305 ◽

Cited By ~ 127

Author(s):

Leif Østergaard ◽

Fred H. Hochberg ◽

James D. Rabinov ◽

A. Gregory Sorensen ◽

Michael Lev ◽

...

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Magnetic Resonance ◽

Brain Tumors ◽

Mr Imaging ◽

Blood Volume ◽

Cerebral Blood Volume ◽

Clinical Effects ◽

Content Type ◽

Fine Print

Object. In this study the authors assessed the early changes in brain tumor physiology associated with glucocorticoid administration. Glucocorticoids have a dramatic effect on symptoms in patients with brain tumors over a time scale ranging from minutes to a few hours. Previous studies have indicated that glucocorticoids may act either by decreasing cerebral blood volume (CBV) or blood-tumor barrier (BTB) permeability and thereby the degree of vasogenic edema.Methods. Using magnetic resonance (MR) imaging, the authors examined the acute changes in CBV, cerebral blood flow (CBF), and BTB permeability to gadolinium-diethylenetriamine pentaacetic acid after administration of dexamethasone in six patients with brain tumors. In patients with acute decreases in BTB permeability after dexamethasone administration, changes in the degree of edema were assessed using the apparent diffusion coefficient of water.Conclusions. Dexamethasone was found to cause a dramatic decrease in BTB permeability and regional CBV but no significant changes in CBF or the degree of edema. The authors found that MR imaging provides a powerful tool for investigating the pathophysiological changes associated with the clinical effects of glucocorticoids.

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Computer-controlled electrical stimulation for quantitative mapping of human cortical function

Journal of Neurosurgery ◽

10.3171/2008.2.jns17666 ◽

2009 ◽

Vol 110 (6) ◽

pp. 1300-1303 ◽

Cited By ~ 8

Author(s):

Mario F. Dulay ◽

Dona K. Murphey ◽

Ping Sun ◽

Yadin B. David ◽

John H. R. Maunsell ◽

...

Keyword(s):

Electrical Stimulation ◽

Detection Threshold ◽

Electrical Current ◽

Controlled Delivery ◽

Cortical Mapping ◽

Cortical Function ◽

Quantitative Mapping ◽

Neurosurgical Patients ◽

Discrete Area ◽

Computer Controlled

Cortical mapping with electrical stimulation (ES) in neurosurgical patients typically involves the manually controlled delivery of suprathreshold electrical current to a discrete area of the brain. Limited numbers of trials and imprecise current delivery methods increase the variability of the behavioral response and make it difficult to collect quantitative mapping data, which is especially important in research studies of human cortical function. To overcome these limitations, the authors developed a method for computer-controlled delivery of defined electrical current to implanted intracranial electrodes. They demonstrate that stimulation can be time locked to a behavioral task to rapidly and systematically measure the detection threshold for ES in human visual cortex over many trials. Computer-controlled ES is well suited for the systematic and quantitative study of the function of virtually any region of cerebral cortex. It may be especially useful for studying human cortical regions that are not well characterized and for verifying the presence of stimulation-evoked percepts that are difficult to objectively confirm.

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Spinal cord grey matter lesions in multiple sclerosis detected by post-mortem high field MR imaging

Multiple Sclerosis Journal ◽

10.1177/1352458508096876 ◽

2008 ◽

Vol 15 (2) ◽

pp. 180-188 ◽

Cited By ~ 49

Author(s):

CP Gilmore ◽

JJG Geurts ◽

N Evangelou ◽

JCJ Bot ◽

RA van Schijndel ◽

...

Keyword(s):

Spinal Cord ◽

White Matter ◽

Mr Imaging ◽

High Field ◽

Grey Matter ◽

Great Majority ◽

Proton Density ◽

Post Mortem ◽

Mr Images ◽

The Brain

Background Post-mortem studies demonstrate extensive grey matter demyelination in MS, both in the brain and in the spinal cord. However the clinical significance of these plaques is unclear, largely because they are grossly underestimated by MR imaging at conventional field strengths. Indeed post-mortem MR studies suggest the great majority of lesions in the cerebral cortex go undetected, even when performed at high field. Similar studies have not been performed using post-mortem spinal cord material. Aim To assess the sensitivity of high field post-mortem MRI for detecting grey matter lesions in the spinal cord in MS. Methods Autopsy material was obtained from 11 MS cases and 2 controls. Proton Density-weighted images of this formalin-fixed material were acquired at 4.7Tesla before the tissue was sectioned and stained for Myelin Basic Protein. Both the tissue sections and the MR images were scored for grey matter and white matter plaques, with the readers of the MR images being blinded to the histopathology results. Results Our results indicate that post-mortem imaging at 4.7Tesla is highly sensitive for cord lesions, detecting 87% of white matter lesions and 73% of grey matter lesions. The MR changes were highly specific for demyelination, with all lesions scored on MRI corresponding to areas of demyelination. Conclusion Our work suggests that spinal cord grey matter lesions may be detected on MRI more readily than GM lesions in the brain, making the cord a promising site to study the functional consequences of grey matter demyelination in MS.

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