Functional Mapping of Human Sensorimotor Cortex with 3D BOLD fMRI Correlates Highly with H215O PET rCBF

Positron emission tomography (PET) functional imaging is based on changes in regional cerebral blood flow (rCBF). Functional magnetic resonance imaging (fMRI) is based on a variety of physiological parameters as well as rCBF. This study is aimed at the cross validation of three-dimensional (3D) fMRI, which is sensitive to changes in blood oxygenation, with oxygen-15-labeled water (H215O) PET. Nine normal subjects repeatedly performed a simple finger opposition task during fMRI scans and during PET scans. Within-subject statistical analysis revealed significant (“activated”) signal changes ( p < 0.05, Bonferroni corrected for number of voxels) in contralateral primary sensorimotor cortex (PSM) in all subjects with fMRI and with PET. With both methods, 78% of all activated voxels were located in the PSM. Overlap of activated regions occurred in all subjects (mean 43%, SD 26%). The size of the activated regions in PSM with both methods was highly correlated ( rho = 0.87, p < 0.01). The mean distance between centers of mass of the activated regions in the PSM for fMRI versus PET was 6.7 mm (SD 3.0 mm). Average magnitude of signal change in activated voxels in this region, expressed as z-values adapted to timeseries, zt, was similar (fMRI 5.5, PET 5.3). Results indicate that positive blood oxygen level-dependent (BOLD) signal changes obtained with 3D principles of echo shifting with a train of observations (PRESTO) fMRI are correlated with rCBF, and that sensitivity of fMRI can equal that of H215O PET.

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The Metabolic Centroid Method for PET Brain Image Analysis

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1989.58 ◽

1989 ◽

Vol 9 (3) ◽

pp. 388-397 ◽

Cited By ~ 20

Author(s):

A. V. Levy ◽

J. D. Brodie ◽

JJ. A. G. Russell ◽

N. D. Volkow ◽

E. Laska ◽

...

Keyword(s):

Random Noise ◽

Three Dimensional ◽

Normal Subjects ◽

Subcortical Structures ◽

Centroid Method ◽

Whole Brain ◽

Positron Emission ◽

The Mean ◽

Brain Image Analysis ◽

The Brain

The method of centroids is an approach to the analysis of three-dimensional whole-brain positron emission tomography (PET) metabolic images. It utilizes the brain's geometric centroid and metabolic centroid so as to objectively characterize the central tendency of the distribution of metabolic activity in the brain. The method characterizes the three-dimensional PET metabolic image in terms of four parameters: the coordinates of the metabolic centroid and the mean metabolic rate of the whole brain. These parameters are not sensitive to spatially uniform random noise or to the position of the subject's head within a uniform PET camera field of view. The method has been applied to 40 normal subjects, 22 schizophrenics who were treated with neuroleptics, and 20 schizophrenics who were neuroleptic-free. The mean metabolic centroid of the normal subjects was found to be superior to the mean geometric centroid of the brain. The mean metabolic centroid of chronic schizophrenics is lower and more posterior to the mean geometric centroid than is that of normals. This difference is greater in medicated than in unmedicated schizophrenics. The posterior and downward displacement of the mean metabolic centroid is consistent with the concepts of hypofrontality, hyperactivity of subcortical structures, and neuroleptic effect in schizophrenics.

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Localization of hand sensory function to the pli de passage moyen of Broca

Journal of Neurosurgery ◽

10.3171/jns.2004.101.2.0278 ◽

2004 ◽

Vol 101 (2) ◽

pp. 278-283 ◽

Cited By ~ 10

Author(s):

Warren W. Boling ◽

André Olivier

Keyword(s):

Three Dimensional ◽

Central Area ◽

Sensory Function ◽

Content Type ◽

Positron Emission ◽

Surface Reconstructions ◽

Highly Correlated ◽

Sensory Activation ◽

Pet Scans ◽

Fine Print

Object. The goal of this study was to identify a reliable landmark for hand sensory function in the central area. Methods. Hand sensory activation on positron emission tomography (PET) scans was analyzed in 27 patients. Each PET study was coregistered with the patient's magnetic resonance image and analyzed in two-dimensional and three-dimensional cortical surface reconstructions to define anatomicofunctional relationships. Conclusions. The substratum of hand sensory function is a prominent fold of cortex elevating the floor of the central sulcus and connecting the pre- and postcentral gyri. Broca named this cortical fold the pli de passage moyen, and hand motor function has been localized to the precentral component of this structure. In this study the authors demonstrate that hand sensory function is highly correlated with the postcentral component of the pli de passage moyen, and that this structure is a reliable cortical landmark for identifying the aforementioned function.

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The Spectral Signature Method for the Analysis of PET Brain Images

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1991.45 ◽

1991 ◽

Vol 11 (1_suppl) ◽

pp. A103-A113 ◽

Cited By ~ 14

Author(s):

Brain Images ◽

A. V. Levy ◽

E. Laska ◽

J. D. Brodie ◽

N. D. Volkow ◽

...

Keyword(s):

Metabolic Activity ◽

Three Dimensional ◽

Feature Space ◽

Normal Subjects ◽

Spectral Signature ◽

Centroid Method ◽

Brain Images ◽

Metabolic Characteristics ◽

Positron Emission ◽

Head Positioning

We introduce the concept of the metabolic centroid spectrum as the feature space to characterize the distribution of metabolic activity in three-dimensional brains. The method computes the metabolic centroid of a brain subvolume for each increment of metabolic activity occurring in the whole brain. The result is the metabolic spectral signature, a continuous three-dimensional curve whose shape reflects the distribution of metabolic rates in the brain. The method's sensitivity to metabolic distribution asymmetries is greatly increased over that of the metabolic centroid method, while retaining its advantages; it is almost invariant to head size, head positioning, photon scatter, and the positron emission tomography (PET) camera's full width at half-maximum. It does not require magnetic resonance, computed tomography, or x-ray images. To test the method we analyzed the metabolic PET images of 40 normal subjects and 20 schizophrenics. The results show a unification of several metabolic characteristics of schizophrenic brains, such as laterality, hypofrontality, cortical/subcortical abnormalities, and overall brain hypometabolism, which were identified by different laboratories in separate studies using differing methodologies. Here they are presented by a single automatic objective method.

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Effect of Semicircular Canal Stimulation on the Perception of the Visual Vertical

Journal of Neurophysiology ◽

10.1152/jn.00960.2002 ◽

2003 ◽

Vol 90 (2) ◽

pp. 622-630 ◽

Cited By ~ 63

Author(s):

Marousa Pavlou ◽

Nicole Wijnberg ◽

Mary E. Faldon ◽

Adolfo M. Bronstein

Keyword(s):

Semicircular Canal ◽

Three Dimensional ◽

Vertical Axis ◽

Normal Subjects ◽

Slow Phase ◽

Visual Vertical ◽

Axis Rotation ◽

Highly Correlated ◽

Head Positions ◽

Direction Opposite

The subjective visual vertical (SVV) is usually considered a measure of otolith function. Herewith we investigate the influence of semicircular canal (SCC) stimulation on the SVV by rotating normal subjects in yaw about an earth-vertical axis, with velocity steps of ± 90°/s, for 60 s. SVV was assessed by setting an illuminated line to perceived earth vertical in darkness, during a per- and postrotary period. Four head positions were tested: upright, 30° backward (chin up) or forward, and ∼40° forward from upright. During head upright/backward conditions, a significant SVV tilt ( P < 0.01) in the direction opposite to rotation was found that reversed during postrotary responses. The rotationally induced SVV tilt had a time constant of decay of ∼30 s. Rotation with the head 30° forward did not affect SVV, whereas the 40° forward tilt caused a direction reversal of SVV responses compared with head upright/backward. Spearman correlation values (Rho) between individual SCC efficiencies in different head positions and mean SVV tilts were 0.79 for posterior, 0.34 for anterior, and – 0.80 for horizontal SCCs. Three-dimensional video-oculography showed that SVV and torsional eye position measurements were highly correlated (0.83) and in the direction opposite to the slow phase torsional vestibuloocular reflex. In conclusion: 1) during yaw axis rotation without reorientation of the head with respect to gravity, the SVV is influenced by SCC stimulation; 2) this effect is mediated by the vertical SCCs, particularly the posterior SCCs; 3) rotationally induced SVV changes are due to torsional ocular tilt; 4) SVV and ocular tilts occur in the “anticompensatory,” fast phase direction of the torsional nystagmus; and 5) clinically, abnormal SVV tilts cannot be considered a specific indication of otolith system dysfunction.

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Repetitive 2HZ-transcranial electromagnetic stimulation induces transsynaptic activation of the primary sensorimotor cortex: Evidence from 18FDG positron emission tomography

Electroencephalography and Clinical Neurophysiology ◽

10.1016/s0013-4694(97)88332-4 ◽

1997 ◽

Vol 103 (1) ◽

pp. 83-84

Author(s):

F Willoch

Keyword(s):

Positron Emission Tomography ◽

Sensorimotor Cortex ◽

Emission Tomography ◽

Electromagnetic Stimulation ◽

Positron Emission ◽

18Fdg Positron Emission Tomography ◽

Primary Sensorimotor Cortex ◽

Transcranial Electromagnetic Stimulation

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Faculty Opinions recommendation of Staging Hemodynamic Failure With Blood Oxygen-Level-Dependent Functional Magnetic Resonance Imaging Cerebrovascular Reactivity: A Comparison Versus Gold Standard (15O-)H2O-Positron Emission Tomography.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.732571633.793542183 ◽

2018 ◽

Author(s):

James Duffin

Keyword(s):

Gold Standard ◽

Blood Oxygen Level Dependent ◽

Cerebrovascular Reactivity ◽

Emission Tomography ◽

Blood Oxygen ◽

Functional Magnetic Resonance ◽

Resonance Imaging ◽

Blood Oxygen Level ◽

Positron Emission ◽

Hemodynamic Failure

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Fast Nonsupervised 3D Registration of PET and MR Images of the Brain

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1994.96 ◽

1994 ◽

Vol 14 (5) ◽

pp. 749-762 ◽

Cited By ~ 66

Author(s):

Jean-François Mangin ◽

Vincent Frouin ◽

Isabelle Bloch ◽

Bernard Bendriem ◽

Jaime Lopez-Krahe

Keyword(s):

Three Dimensional ◽

Magnetic Resonance Images ◽

Surface Matching ◽

3D Registration ◽

Matching Algorithm ◽

Distance Map ◽

Brain Surface ◽

Discrete Surfaces ◽

Positron Emission ◽

The Brain

We propose a fully nonsupervised methodology dedicated to the fast registration of positron emission tomography (PET) and magnetic resonance images of the brain. First, discrete representations of the surfaces of interest (head or brain surface) are automatically extracted from both images. Then, a shape-independent surface-matching algorithm gives a rigid body transformation, which allows the transfer of information between both modalities. A three-dimensional (3D) extension of the chamfer-matching principle makes up the core of this surface-matching algorithm. The optimal transformation is inferred from the minimization of a quadratic generalized distance between discrete surfaces, taking into account between-modality differences in the localization of the segmented surfaces. The minimization process is efficiently performed via the precomputation of a 3D distance map. Validation studies using a dedicated brain-shaped phantom have shown that the maximum registration error was of the order of the PET pixel size (2 mm) for the wide variety of tested configurations. The software is routinely used today in a clinical context by the physicians of the Service Hospitalier Frédéric Joliot (>150 registrations performed). The entire registration process requires ∼5 min on a conventional workstation.

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