Correspondence between functional magnetic resonance imaging somatotopy and individual brain anatomy of the central region: comparison with intraoperative stimulation in patients with brain tumors

2000 ◽  
Vol 92 (4) ◽  
pp. 589-598 ◽  
Author(s):  
Stéphane Lehéricy ◽  
Hugues Duffau ◽  
Philippe Cornu ◽  
Laurent Capelle ◽  
Bernard Pidoux ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Magnetic Resonance ◽  
Brain Tumors ◽  
Central Region ◽  
Anatomical Landmarks ◽  
Functional Magnetic Resonance ◽  
Central Sulcus ◽  
Content Type ◽  
Fine Print ◽  
Motor Areas

Object. The goal of this study was to determine the somatotopical structure—function relationships of the primary motor cortex in individual patients by using functional magnetic resonance (fMR) imaging. This was done to assess whether there is a displacement of functional areas compared with anatomical landmarks in patients harboring brain tumors close to the central region, and to validate these findings with intraoperative cortical stimulation.Methods. One hundred twenty hemispheres in 60 patients were studied by obtaining blood oxygen level—dependent fMR images in patients while they performed movements of the foot, hand, and face on both sides. There was a good correspondence between anatomical landmarks in the deep portion of the central sulcus on axial slices and the somatotopical organization of primary motor areas. Pixels activated during hand movements were centered on a small characteristic digitation; those activated during movements in the face and foot areas were located in the lower portion of the central sulcus (lateral to the hand area) and around the termination of the central sulcus, respectively. In diseased hemispheres, signal-intensity changes were still observed in the projection of the expected anatomical area. The fMR imaging data mapped intraoperative electrical stimulation in 92% of positive sites.Conclusions. There was a high correspondence between the somatotopical anatomy and function in the central sulcus, which was similar in normal and diseased hemispheres. The fMR imaging and electrical stimulation data were highly concordant. These findings may enable the neurosurgeon to locate primary motor areas more easily during surgery.

Clinical application of functional magnetic resonance imaging in presurgical identification of the central sulcus

1998 ◽  
Vol 88 (5) ◽  
pp. 863-869 ◽  
Author(s):  
Jesús Pujol ◽  
Gerardo Conesa ◽  
Joan Deus ◽  
Luis López-Obarrio ◽  
Fabián Isamat ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Three Dimensional ◽  
Functional Magnetic Resonance ◽  
Central Sulcus ◽  
Clinical Context ◽  
Content Type ◽  
Sensorimotor Region ◽  
Specific Factors ◽  
Eloquent Cortex ◽  
Fine Print

Object. The authors sought to evaluate the advantages and limitations of functional magnetic resonance (fMR) imaging when it was used regularly in the clinical context to identify the central sulcus. Methods. A 1.5-tesla MR system comprising a spoiled gradient recalled acquisition in the steady-state functional sequence and a cross-hand cancellation analysis method were used to evaluate 50 surgical candidates with centrally located space-occupying lesions in the brain. Three-dimensional (3-D) models of the patient's head and brain showing the relative position of the tumor and the eloquent cortex were obtained in each case. A selective and reproducible focal activation was found, indicating the probable central sulcus position in 41 patients (82%). Direct cortical stimulation confirmed the fMR findings in 100% of 22 intraoperatively assessed patients. Failure to identify the central sulcus occurred in 18% of cases and was mainly a consequence of intrinsic damage in the primary sensorimotor region that resulted in severe hand paresis. Conclusions. Although specific factors were identified that contributed to reduced sensitivity of fMR imaging in the clinical context, the present study supports functional assessment and 3-D representation of specific surgical situations as generally feasible in common practice.

Localization of human frontal eye fields: anatomical and functional findings of functional magnetic resonance imaging and intracerebral electrical stimulation

2001 ◽  
Vol 95 (5) ◽  
pp. 804-815 ◽  
Author(s):  
Elie Lobel ◽  
Philippe Kahane ◽  
Ute Leonards ◽  
Marie-Hélène Grosbras ◽  
Stéphane Lehéricy ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Magnetic Resonance ◽  
3 Tesla ◽  
Frontal Eye Fields ◽  
Precentral Gyrus ◽  
Functional Magnetic Resonance ◽  
Content Type ◽  
Cortical Areas ◽  
Fine Print

Object. The goal of this study was to investigate the anatomical localization and functional role of human frontal eye fields (FEFs) by comparing findings from two independently conducted studies. Methods. In the first study, 3-tesla functional magnetic resonance (fMR) imaging was performed in 14 healthy volunteers divided into two groups: the first group executed self-paced voluntary saccades in complete darkness and the second group repeated newly learned or familiar sequences of saccades. In the second study, intracerebral electrical stimulation (IES) was performed in 38 patients with epilepsy prior to surgery, and frontal regions where stimulation induced versive eye movements were identified. These studies showed that two distinct oculomotor areas (OMAs) could be individualized in the region classically corresponding to the FEFs. One OMA was consistently located at the intersection of the superior frontal sulcus with the fundus of the superior portion of the precentral sulcus, and was the OMA in which saccadic eye movements could be the most easily elicited by electrical stimulation. The second OMA was located more laterally, close to the surface of the precentral gyrus. The fMR imaging study and the IES study demonstrated anatomical and stereotactic agreement in the identification of these cortical areas. Conclusions. These findings indicate that infracentimetric localization of cortical areas can be achieved by measuring the vascular signal with the aid of 3-tesla fMR imaging and that neuroimaging and electrophysiological recording can be used together to obtain a better understanding of the human cortical functional anatomy.

Functional magnetic resonance imaging of sensory and motor cortex: comparison with electrophysiological localization

1995 ◽  
Vol 83 (2) ◽  
pp. 262-270 ◽  
Author(s):  
Aina Puce ◽  
R. Todd Constable ◽  
Marie L. Luby ◽  
Gregory McCarthy ◽  
Anna C. Nobre ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Magnetic Resonance ◽  
Motor Cortex ◽  
Mr Imaging ◽  
Sensorimotor Cortex ◽  
Functional Magnetic Resonance ◽  
Planar Imaging ◽  
Content Type ◽  
Functional Mr Imaging ◽  
Fine Print

✓ Functional magnetic resonance (MR) imaging was performed using a 1.5-tesla MR system to localize sensorimotor cortex. Six neurologically normal subjects were studied by means of axial gradient-echo images with a motor task and one or more sensory tasks: 1) electrical stimulation of the median nerve; 2) continuous brushing over the thenar region; and 3) pulsed flow of compressed air over the palm and digits. An increased MR signal was observed in or near the central sulcus, consistent with the location of primary sensory and motor cortex. Four patients were studied using echo planar imaging sequences and motor and sensory tasks. Three patients had focal refractory seizures secondary to a lesion impinging on sensorimotor cortex. Activation seen on functional MR imaging was coextensive with the location of the sensorimotor area determined by evoked potentials and electrical stimulation. Functional MR imaging provides a useful noninvasive method of localization and functional assessment of sensorimotor cortex.

Presurgical motor and somatosensory cortex mapping with functional magnetic resonance imaging and positron emission tomography

1999 ◽  
Vol 91 (6) ◽  
pp. 915-921 ◽  
Author(s):  
Richard G. Bittar ◽  
André Olivier ◽  
Abbas F. Sadikot ◽  
Frederick Andermann ◽  
G. Bruce Pike ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Magnetic Resonance ◽  
Emission Tomography ◽  
Functional Magnetic Resonance ◽  
Central Sulcus ◽  
Content Type ◽  
Positron Emission ◽  
Pet Scanning ◽  
Functional Localization ◽  
Fine Print

Object. Accurate identification of eloquent cortex is important to ensure that resective surgery in the region surrounding the central sulcus is performed with minimum risk of permanent neurological deficit. Functional localization has traditionally been accomplished using intraoperative cortical stimulation (ICS). However, this technique suffers from several disadvantages that make the development and validation of noninvasive methods desirable. Functional localization accomplished by activation studies in which positron emission tomography (PET) scanning and the tracer [15O]H2O have been used has been shown to correlate well with the results of ICS. Another noninvasive method for functional localization is functional magnetic resonance (fMR) imaging. We compared the locations of activation peaks obtained in individual patients using fMR and [15O]H2O PET imaging.Methods. Twenty-six combined PET activation—fMR imaging studies were performed in 11 patients who were admitted for evaluation before undergoing surgery in the region surrounding the central sulcus. The PET scans were obtained using bolus injections of the cerebral blood flow tracer [15O]H2O (10 mCi). Multislice T2*-weighted gradient-echo echoplanar images were acquired using a 1.5-tesla MR imaging system. Activation maps were aligned with anatomical MR images and transformed into stereotactic space, after which the locations of activation peaks obtained using both modalities were compared. The average distance between activation peaks obtained using fMR imaging and those obtained using PET imaging was 7.9 ± 4.8 mm (p > 0.05), with 96% of the peaks being located on either the same or adjacent sulci and gyri. Overlapping of voxels activated by each modality occurred in 92% of the studies. Functional MR imaging failed to activate the primary sensorimotor cortex in one study and produced results that were ambiguous in the clinical setting in three cases.Conclusions. Overall, fMR imaging produced activation that correlated well with that obtained using PET scanning. Discrepancies between the sites of activation identified using these two techniques may reflect differences in their physiological bases.

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

1999 ◽  
Vol 90 (2) ◽  
pp. 300-305 ◽  
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.

Sources of error in comparing functional magnetic resonance imaging and invasive electrophysiological recordings

2000 ◽  
Vol 93 (2) ◽  
pp. 214-223 ◽  
Author(s):  
Derek L. G. Hill ◽  
Andrew D. Castellano Smith ◽  
Andrew Simmons ◽  
Calvin R. Maurer ◽  
Timothy C. S. Cox ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Healthy Volunteers ◽  
Hand Movement ◽  
Epileptogenic Zone ◽  
Imaging Data ◽  
Functional Magnetic Resonance ◽  
Reliable Technique ◽  
Content Type ◽  
The Brain ◽  
Fine Print

Object. Several authors have recently reported studies in which they aim to validate functional magnetic resonance (fMR) imaging against the accepted gold standard of invasive electrophysiological monitoring. The authors have conducted a similar study, and in this paper they identify and quantify two characteristics of these data that can make such a comparison problematic.Methods. Eight patients in whom surgery for epilepsy was performed and five healthy volunteers underwent fMR imaging to localize the part of the sensorimotor cortex responsible for hand movement. In the patient group subdural electrode mats were subsequently implanted to identify eloquent regions of the brain and the epileptogenic zone. The fMR imaging data were processed to correct for motion during the study and then registered with a postimplantation computerized tomography (CT) scan on which the electrodes were visible. The motion during imaging in the two groups studied, and the deformation of the brain between the preoperative images and postoperative scans were measured.The patients who underwent epilepsy surgery moved significantly more during fMR imaging experiments than healthy volunteers performing the same motor task. This motion had a particularly increased out-of-plane component and was significantly more correlated with the stimulus than in the volunteers. This motion was especially increased when the patients were performing a task on the side affected by the lesion. The additional motion is hard to correct and substantially degrades the quality of the resulting fMR images, making it a much less reliable technique for use in these patients than in others. Also, the authors found that after electrode implantation, the brain surface can shift more than 10 mm relative to the skull compared with its preoperative location, substantially degrading the accuracy of the comparison of electrophysiological measurements made in the deformed brain and fMR studies obtained preoperatively.Conclusions. These two findings indicate that studies of this sort are currently of limited use for validating fMR imaging and should be interpreted with care. Additional image analysis research is necessary to solve the problems caused by patients' motion and brain deformation.

Utility of relative cerebral blood volume mapping derived from perfusion magnetic resonance imaging in the routine follow up of brain tumors

1997 ◽  
Vol 86 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Tali Siegal ◽  
Rina Rubinstein ◽  
Tzahala Tzuk-Shina ◽  
John M. Gomori
Keyword(s):  
Magnetic Resonance ◽  
Brain Tumors ◽  
Mr Imaging ◽  
Blood Volume ◽  
Clinical Assessment ◽  
Cerebral Blood Volume ◽  
Content Type ◽  
Relative Cerebral Blood Volume ◽  
Fine Print

✓ It was recently demonstrated that imaging of brain tumors by relative cerebral blood volume (CBV) maps reconstructed from dynamic magnetic resonance (MR) data provide similar diagnostic information compared to positron emission tomography (PET) or 201Tl single-photon emission computerized tomography (201Tl-SPECT) scans. The authors used relative CBV mapping for routine follow-up evaluation of patients with brain tumors and compared its sensitivity to diagnostic MR imaging, 201Tl-SPECT and clinical assessment. Fifty-nine patients were prospectively followed using 191 concomitant studies of dual section relative CBV maps, MR imaging, 201Tl-SPECT, and neurological evaluations. Studies were repeated every 2 to 3 months (median three evaluations/patient). The relative CBV maps were graded as relative CBV 0 to 4, where Grades 3 and 4 are indicative of proliferating tumors (four = rapid leak). There were 44 high-grade and 15 low-grade tumors followed during treatment. During the follow-up period a change in relative CBV grade was observed in 56% of the patients, revealing an increasing grade in 72% of them. The rapid leak phenomenon was detected in 35% of all studies and in 81% of those with a worsening relative CBV grade. Tumor progression was detected earlier by relative CBV maps as follows: earlier than MR imaging in 32% of the studies (earlier by a median of 4.5 months; p < 0.01); earlier than 201Tl-SPECT in 63% (median 4.5 months; p < 0.01), and earlier than clinical assessment in 55% (median 6 months; p < 0.01). In 82% of studies with positive MR imaging but negative 201Tl-SPECT, the lesions were smaller than 1.5 cm. The relative CBV maps clearly delineated the appearance of rapid leak in these lesions. Routine use of relative CBV maps that can be implemented on any high-field MR unit and added to the regular MR evaluation provides useful functional information in patients with brain tumors. When used as an adjunct follow-up evaluation it proved more sensitive than the other modalities for early prediction of tumor growth. It is very sensitive to small regional changes, unlike functional imaging such as PET or SPECT scans. Based on previous experience with 76 regional CBV studies, the authors conclude that regional CBV mapping correlates with active tumor and it may separate enhancing scar and radiation injury from infiltrative tumor. A new effect named the rapid leak phenomenon was also observed; this phenomenon, as identified on the regional CBV maps, correlates with high malignancy.

Discordance between functional magnetic resonance imaging during silent speech tasks and intraoperative speech arrest

2005 ◽  
Vol 103 (2) ◽  
pp. 267-274 ◽  
Author(s):  
Nicole Petrovich ◽  
Andrei I. Holodny ◽  
Viviane Tabar ◽  
Denise D. Correa ◽  
Joy Hirsch ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Inferior Frontal Gyrus ◽  
Hemispheric Dominance ◽  
Cortical Mapping ◽  
Precentral Gyrus ◽  
Functional Magnetic Resonance ◽  
Content Type ◽  
Neurosurgical Planning ◽  
Silent Speech ◽  
Fine Print

Object. The goal of this study was to investigate discordance between the location of speech arrest during awake cortical mapping, a common intraoperative indicator of hemispheric dominance, and silent speech functional magnetic resonance (fMR) imaging maps of frontal language function. Methods. Twenty-one cases were reviewed retrospectively. Images of silent speech fMR imaging activation were coregistered to anatomical MR images obtained for neuronavigation. These were compared with the intraoperative cortical photographs and the behavioral results of electrocorticography during awake craniotomy. An fMR imaging control study of three healthy volunteers was then conducted to characterize the differences between silent and vocalized speech fMR imaging protocols used for neurosurgical planning. Conclusions. Results of fMR imaging showed consistent and predominant activation of the inferior frontal gyrus (IFG) during silent speech tasks. During intraoperative mapping, however, 16 patients arrested in the precentral gyrus (PRG), well posterior to the fMR imaging activity. Of those 16, 14 arrested only in the PRG and not in the IFG as silent speech fMR imaging predicted. The control fMR imaging study showed that vocalized speech fMR imaging shifts the location of the fMR imaging prediction to include the motor strip and may be more appropriate for neurosurgical planning.

Measurement of tumor resection volumes from computerized images

1992 ◽  
Vol 77 (1) ◽  
pp. 151-154 ◽  
Author(s):  
Duc H. Duong ◽  
Robert C. Rostomily ◽  
David R. Haynor ◽  
G. Evren Keles ◽  
Mitchel S. Berger
Keyword(s):  
Magnetic Resonance ◽  
Brain Tumors ◽  
Tumor Resection ◽  
Region Of Interest ◽  
Magnetic Resonance Images ◽  
Content Type ◽  
Slide Scanner ◽  
Program Error ◽  
Fine Print ◽  
Area And Volume

✓ The authors describe a method for quantitation of the area and volume of the resection cavity in patients who have undergone surgery for brain tumors. Using a slide scanner and Image 1.27, a public domain program for the Apple Macintosh II computer, computerized tomography scans and magnetic resonance images can be digitized and analyzed for a particular region of interest, such as the area and volume of tumor on preoperative and postresection scans. Phantom scans were used to analyze the accuracy of the program and the program users. User error was estimated at 2%, program error was 4.5%. This methodology is proposed as a means of retrospectively calculating the extent of tumor resection.

Individual variations in the sulcal anatomy of the basal temporal lobe and its relevance for epilepsy surgery: an anatomical study performed using magnetic resonance imaging

2002 ◽  
Vol 96 (3) ◽  
pp. 464-473 ◽  
Author(s):  
Klaus Novak ◽  
Thomas Czech ◽  
Daniela Prayer ◽  
Wolfgang Dietrich ◽  
Wolfgang Serles ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Temporal Lobe ◽  
Anatomical Landmarks ◽  
Resonance Imaging ◽  
Mr Images ◽  
Hippocampal Region ◽  
Content Type ◽  
Individual Variations ◽  
Fine Print

Object. The concept of selective amygdalohippocampectomy is based on pathophysiological insights into the epileptogenicity of the hippocampal region and the definition of the clinical syndrome of mesial temporal lobe epilepsy (TLE). High-resolution magnetic resonance (MR) imaging allows correlation of the site of histologically conspicuous tissue with anatomical structure. The highly variable sulcal pattern of the basal temporal lobe, however, definitely complicates the morphometric analysis of histomorphologically defined subdivisions of the hippocampal region. The goal of this study was to define individual variations in the sulcal anatomy on the basis of preoperative MR images obtained in patients suffering from TLE. Methods. The authors analyzed coronal MR images obtained in 50 patients for the presence of and intrinsic relationships among the rhinal, collateral, and occipitotemporal sulci. The surface relief of consecutive sections of 100 temporal lobes was graphically outlined and the resulting maps were used for visual analysis. The sulci were characterized by measurement of their depth, distance to the temporal horn, and laterality. The anatomical measurements and frequencies of sulcal patterns were assessed for statistical correlation with patients' histories and the lateralization of the seizure focus. Conclusions. Statistical assessment shows that patient sex is a significant factor in sulcal patterns. Anatomical measurements are significantly decreased on the side of the seizure origin, which relates to loss of white matter, a known morphological abnormality associated with TLE. Magnetic resonance imaging allows for accurate preoperative knowledge of individual sulcal patterns and facilitates intraoperative orientation to anatomical landmarks.

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