scholarly journals The Metabolic Centroid Method for PET Brain Image Analysis

1989 ◽  
Vol 9 (3) ◽  
pp. 388-397 ◽  
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.

scholarly journals The Spectral Signature Method for the Analysis of PET Brain Images

1991 ◽  
Vol 11 (1_suppl) ◽  
pp. A103-A113 ◽  
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.

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

1994 ◽  
Vol 14 (5) ◽  
pp. 749-762 ◽  
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.

scholarly journals Reproducibility of Cerebral Glucose Metabolic Measurements in Resting Human Subjects

1988 ◽  
Vol 8 (4) ◽  
pp. 502-512 ◽  
Author(s):  
Elsa J. Bartlett ◽  
Jonathan D. Brodie ◽  
Alfred P. Wolf ◽  
David R. Christman ◽  
Eugene Laska ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Brain Metabolism ◽  
Human Subjects ◽  
Normal Subjects ◽  
Time Of Day ◽  
Cerebral Glucose Metabolism ◽  
Whole Brain ◽  
Positron Emission ◽  
Subcortical Regions ◽  
Regional Cerebral Glucose Metabolism

Positron emission tomography with 11C-2-deoxyglucose was used to determine the test-retest variability of regional cerebral glucose metabolism in 22 young normal right-handed men scanned twice in a 24-h period under baseline (resting) conditions. To assess the effects of scan order and time of day on variability, 12 subjects were scanned in the morning and afternoon of the same day (a.m.-p.m.) and 10 in the reverse order (p.m.-a.m.) with a night in between. The effect of anxiety on metabolism was also assessed. Seventy-three percent of the total subject group showed changes in whole brain metabolism from the first to the second measurement of 10% or less, with comparable changes in various cortical and subcortical regions. When a scaling factor was used to equate the whole brain metabolism in the two scans for each individual, the resulting average regional changes for each group were no mote than 1%. This suggests that the proportion of the whole brain metabolism utilized regionally is stable in a group of subjects over time. Both groups of subjects had lower morning than afternoon metabolism, but the differences were slight in the p.m.-a.m. group. One measure of anxiety (pulse at fun 1) was correlated with run 1 metabolism and with the percentage of change from run 1 to run 2. No significant run 2 correlations were observed. This is the first study to measure test-retest variability in cerebral glucose metabolism in a large sample of young normal subjects. It demonstrates that the deoxyglucose method yields low Intrasubject variability and high stability over a 24-h period.

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

1996 ◽  
Vol 16 (5) ◽  
pp. 755-764 ◽  
Author(s):  
Nick F. Ramsey ◽  
Brenda S. Kirkby ◽  
Peter Van Gelderen ◽  
Karen F. Berman ◽  
Jeff H. Duyn ◽  
...  
Keyword(s):  
Sensorimotor Cortex ◽  
Three Dimensional ◽  
Normal Subjects ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygenation ◽  
Positron Emission ◽  
Signal Changes ◽  
Highly Correlated ◽  
Centers Of Mass ◽  
H215o Pet

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.

Cerebral areas associated with motor control of speech in humans

1997 ◽  
Vol 83 (5) ◽  
pp. 1438-1447 ◽  
Author(s):  
K. Murphy ◽  
D. R. Corfield ◽  
A. Guz ◽  
G. R. Fink ◽  
R. J. S. Wise ◽  
...  
Keyword(s):  
Motor Control ◽  
Language Processing ◽  
Supplementary Motor Area ◽  
Normal Subjects ◽  
Control Of Breathing ◽  
Emission Tomography ◽  
Statistical Comparison ◽  
Cerebral Control ◽  
Positron Emission ◽  
The Brain

Murphy, K., D. R. Corfield, A. Guz, G. R. Fink, R. J. S. Wise, J. Harrison, and L. Adams. Cerebral areas associated with motor control of speech in humans. J. Appl. Physiol. 83(5): 1438–1447, 1997.—We have defined areas in the brain activated during speaking, utilizing positron emission tomography. Six normal subjects continuously repeated the phrase “Buy Bobby a poppy” (requiring minimal language processing) in four ways: A) spoken aloud, B) mouthed silently, C) without articulation, and D) thought silently. Statistical comparison of images from conditions Awith C and B with D highlighted areas associated with articulation alone, because control of breathing for speech was controlled for; we found bilateral activations in sensorimotor cortex and cerebellum with right-sided activation in the thalamus/caudate nucleus. Contrasting images from conditions A with B and C with D highlighted areas associated with the control of breathing for speech, vocalization, and hearing, because articulation was controlled for; we found bilateral activations in sensorimotor and motor cortex, close to but distinct from the activations in the preceding contrast, together with activations in thalamus, cerebellum, and supplementary motor area. In neither subtraction was there activation in Broca’s area. These results emphasize the bilaterality of the cerebral control of “speaking” without language processing.

scholarly journals Dosimetric study of whole-brain irradiation with high-energy photon beams for dose reduction to the scalp

2020 ◽  
Vol 93 (1114) ◽  
pp. 20200159
Author(s):  
Masafumi Sawada ◽  
Etsuo Kunieda ◽  
Takeshi Akiba ◽  
Shigeto Kabuki ◽  
Ryuta Nagao ◽  
...  
Keyword(s):  
High Energy ◽  
High Energy Photon ◽  
Photon Beams ◽  
Whole Brain Irradiation ◽  
Energy Photon ◽  
Whole Brain ◽  
Brain Irradiation ◽  
Brain Surface ◽  
The Mean ◽  
The Brain

Objective: To evaluate the efficiency of high-energy photons for mitigating alopecia due to whole-brain irradiation (WBRT). Methods: Planning CT data from 10 patients who received WBRT were collected. We prepared 4 WBRT plans that used 6 or 15 MV photon beams, with or without use of a field-in-field (FiF) technique, and compared outcomes using a treatment planning system. The primary outcome was dose parameters to the scalp, including the mean dose, maximum dose, and dose received to 50% scalp (D50%). Secondary outcomes were minimum dose to the brain surface. Results: Using FiF, the mean doses were 24.4–26.0 and 22.4–24.1 Gy, and the maximum doses were 30.5–32.1 and 28.5–30.8 Gy for 6 and 15 MV photon beams, respectively. Without FiF, the mean doses were 24.6–26.9 and 22.6–24.5 Gy, and the maximum doses were 30.8–34.6 and 28.6–32.4 Gy for 6 and 15 MV photon beams. The 15 MV plan resulted in a lower scalp dose for each dose parameter (p < 0.001). Using FiF, the minimum doses to the brain surface for the 6 and 15 MV plans were 28.9 ± 0.440 and 29.0 ± 0.557 Gy, respectively (p = 0.70). Without FiF, the minimum doses to the brain surface for the 6 and 15 MV plans were 28.9 ± 0.456 and 29.0 ± 0.529, respectively (p = 0.66). Conclusion: Compared with the 6 MV plan, the 15 MV plan achieved a lower scalp dose without impairing the brain surface dose. Advances in knowledge: High-energy photon WBRT may mitigate alopecia of patients who receiving WBRT.

scholarly journals Glymphatic pathways in the gyrencephalic brain

2021 ◽  
pp. 0271678X2199617
Author(s):  
Nicholas Burdon Bèchet ◽  
Nagesh C Shanbhag ◽  
Iben Lundgaard
Keyword(s):  
Interstitial Fluid ◽  
Three Dimensional ◽  
Light Sheet ◽  
Subcortical Structures ◽  
Large Mammal ◽  
Glymphatic System ◽  
Light Sheet Microscopy ◽  
Tracer Distribution ◽  
The Brain ◽  
Solute Clearance

Identification of the perivascular compartment as the point of exchange between cerebrospinal fluid (CSF) and interstitial fluid mediating solute clearance in the brain, named the glymphatic system, has emerged as an important clearance pathway for neurotoxic peptides such as amyloid-beta. However, the foundational science of the glymphatic system is based on rodent studies. Here we investigated whether the glymphatic system exists in a large mammal with a highly gyrified brain. CSF penetration into the brain via perivascular pathways, a hallmark of glymphatic function, was seen throughout the gyrencephalic cortex and subcortical structures, validating the conservation of the glymphatic system in a large mammal. Macroscopic CSF tracer distribution followed the sulci and fissures showing that these folds enhance CSF dispersion. Three-dimensional renditions from light sheet microscopy showed a PVS influx density 4-fold larger in the pig brain than in mice. This demonstrates the existence of an advanced solute transport system in the gyrencephalic brain that could be utilised therapeutically for enhancing waste clearance.

scholarly journals Brain Organization in Schizophrenia

1986 ◽  
Vol 6 (4) ◽  
pp. 441-446 ◽  
Author(s):  
Nora D. Volkow ◽  
Jonathan D. Brodie ◽  
Alfred P. Wolf ◽  
Francisco Gomez-Mont ◽  
Robert Cancro ◽  
...  
Keyword(s):  
Brain Metabolism ◽  
Right Hemisphere ◽  
Normal Subjects ◽  
Brain Regions ◽  
Subcortical Structures ◽  
Brain Organization ◽  
Positron Emission ◽  
The Matrix ◽  
Schizophrenic Patients ◽  
Brain Factor

Brain metabolism was measured with positron emission tomography and [11C]deoxyglucose during baseline and during a visual task in 12 normal subjects and 18 schizophrenic patients. Global measures of metabolism for 11 brain regions were transformed into relative values by dividing them by the metabolic value for whole brain. Factor analysis was accomplished on the matrix of intercorrelations among the relative regional values for the normal and for the schizophrenic patients under baseline and under the task. Four factors that revealed independently varying metabolism in frontal, occipital, left-versus-right hemisphere, and subcortical structures were obtained. The frontal and subcortical factors discriminated between normal subjects and schizophrenic patients, whereas the occipital factor discriminated between baseline and task. Although activity in these individual regions varied significantly, it was the pattern of differences in regional metabolic activity that best discriminated between diagnostic groups and testing conditions.

scholarly journals Crista Volume Measured from 3D Reconstructions of Weightbearing CT Scans Shows a Relationship to Sesamoid Station

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0017
Author(s):  
Stephen F. Conti ◽  
Audrey Clarke ◽  
Matthew S. Conti ◽  
Scott J. Ellis ◽  
Mark C. Miller ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Three Dimensional ◽  
Normal Subjects ◽  
T Test ◽  
3D Reconstructions ◽  
Reliable Technique ◽  
Plantar Surface ◽  
First Metatarsal ◽  
The Mean ◽  
Relationship Of

Category: Bunion Introduction/Purpose: The progression of hallux valgus (HV) deformities results in dislocation of the sesamoids from their position (station) under the plantar surface of the distal first metatarsal. With this dislocation, the crista separating the two sesamoids erodes as the contact of the medial sesamoid with the crista applies pressure with weightbearing. Recently, three dimensional (3D) reconstructions of the metatarsals and first phalanx have demonstrated a means to find a consistently quantify first metatarsal pronation. These same reconstructions can also produce a reliable technique to compute the volumes of the bones involved. The purpose of the current investigation is to examine the relationship of the volume of the crista to pronation and to sesamoid station. Methods: Eleven HV patients and five normal subjects with weightbearing or weightbearing equivalent CT (WBCT) imaging were randomly selected from the senior author’s patients. Pronation was quantified on WBCT scans using 3D reconstructions as described by Campbell et al. (FAI 2018). Crista volume was determined using a line drawn to connect the nadir of each sulcus on either side of the intersesamoidal crista in each slice of the WBCT image (Figure 1). Sesamoid station was also quantified on WBCT scans using the established four point categorization. A linear regression was performed to determine if the volume of the crista was associated with the pronation angle. The sesamoid station was simplified into two categories - mild medial sesamoid subluxation (less than 50% of the medial sesamoid was lateral to the nadir of the crista) and severe medial sesamoid subluxation - and crista volume between these two groups was compared using a t-test. Results: The regression of crista volume against first metatarsal pronation angle did not show statistical significance (P=0.94, r2=0.03). The mean crista volume in the mild medial sesamoid subluxation group was 156(+-47, range 72 - 231)mm3. The mean crista volume in severe medial sesamoid subluxation was 95 (SD 39, range 35 - 160) mm3. The t-test using simplified sesamoid station to compare crista volumes found that the mean crista volume in the mild medial sesamoid subluxation group was statistically significantly greater the than the mean crista volume in the severe sesamoid subluxation group (P=0.01). Conclusion: In HV, it has been hypothesized that the medial sesamoid erodes the crista resulting in arthritis. This is often overlooked as a source of pain in these patients. Our study found that pronation of the first metatarsal was not correlated with crista volume suggesting that pronation does not affect erosion of the crista. Instead, our results are the first to demonstrate that medial sesamoid subluxation as determined from sesamoid station results in erosion of the crista. This supports the hypothesis that sesamoid subluxation, arthritis, and crista erosion are important components of the HV deformity.

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