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At least 19 recordsLinked to original sources
PubMed2001

Mathematical segmentation of grey matter, white matter and cerebral spinal fluid from MR image pairs.

The aims of this study were (1) to design a mathematical segmentation technique to allow extraction of grey matter, white matter and cerebral spinal fluid volumes from paired high resolution MR images and (2) to document the statistical accuracy of the method with different image combinations. A series of linear equations were derived that describe proportional tissue volumes in individual image voxels. The equations use estimates of pure tissue values to derive the proportion of each tissue within a single voxel. Repeatability of manual estimations of pure tissue values was assessed both using regions of interest and thresholding techniques. Statistical accuracy of tissue estimations for a variety of image pairs was assessed from measurements of root-mean-square noise and mean grey level intensity. The technique was used to produce parametric images of grey and white matter distribution. The segmentation technique showed greatest statistical accuracy when the first image has high grey/white matter contrast and the second image has little contrast or the rank order of the signal intensities from pure tissue is reversed. A combination of inversion recovery fast spin echo and fast FLAIR images produced a statistical error of 11% for grey matter and 10% for white matter for any given voxel. The effect of increasing sample size improves both of these figures to give a 1% statistical error on a 100 pixel sample.

Algorithms↗
PubMed1985

Normal frontal lobe gray matter-white matter CT volume ratio in children.

We attempted to establish a computed tomographic value representing the normal volume ratio of gray matter to white matter (G/W) in children in order to have a baseline for studying various developmental disorders such as white matter hypoplasia. The records of 150 children 16 years of age or younger who had normal cranial computed tomography were reviewed. From these a group of 119 were excluded for various reasons. The remaining 31 were presumed to have normal brains. Using the region of interest function for tracing gray and white matter boundaries, superior and ventral to the foramen of Munro area, measurements were determined for consecutive adjacent frontal slices. Volumes were then calculated for both gray and white matter. A volume ratio of 2.010 (sigma = 0.349), G/W, was then derived from each of 31 children. The clinical value of this ratio will be determined by future investigation.

Adolescent↗
PubMed1986

Differences in function and structure of the capillary endothelium in gray matter, white matter and a circumventricular organ of rat brain.

Physiological and morphometric studies were conducted on the microvascular endothelium of four individual cerebral structures having different neural activities--the inferior colliculus, sensorimotor cortex (both gray matter regions), genu of the corpus callosum (white matter), and the subfornical organ (a circumventricular organ) of rats. The physiological data, obtained by quantitative autoradiography, produced new findings: the rate of blood-to-tissue flux across capillary endothelial cells of a neutral amino acid, 14C-alpha-aminoisobutyric acid, was 100-400 X more rapid in the subfornical organ than in gray and white matter regions, and the transit time of labeled albumin in the subfornical organ microcirculation was 7-12 X longer than in the blood-brain barrier regions. These quantitative studies suggest that circulating messengers, such as hormones, would have more prolonged receptor contact with capillary endothelial cells and greater rates of transendothelial passage in the subfornical organ than in gray or white matter. Capillary densities, volume fractions, and surface areas were similar for the inferior colliculus (which has the highest rates of tissue glucose metabolism and blood flow among blood-brain barrier regions) and the subfornical organ, but were significantly smaller for sensorimotor cortex and corpus callosum (about 35 and 70% lower, respectively). Electron microscopic morphometry of capillary endothelial cells in the inferior colliculus and corpus callosum indicated the ultrastructural basis of blood-brain barrier mechanisms in these regions--intercellular junctions that appeared tight, few cytoplasmic vesicular profiles, and no fenestrations. Analysis of endothelial cells in the subfornical organ demonstrated 7 X more vesicular profiles and 4 fenestrations per cross section of capillary. These findings represent structural evidence for high rates of solute flux across the capillary endothelium of circumventricular organs.

Animals↗
PubMed1978

A statistical method for determining the proportions of gray matter, white matter, and CSF using computed tomography.

The brain may be considered as a collection of volume elements (voxels) containing unknown proportions of gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). If one assumes that (1) the attenuation coefficients for voxels with the same proportions of GM, WM, and CSF follow a Gaussian distribution whose mean is a weighted average of the mean attenuation coefficients of pure GM, WM, and CSF and (2) the voxel-to-voxel variation in proportion follows a Dirichlet probability distribution, then the overall proportions of GM, WM, and CSF can be calculated by optimizing the parameters of a compound Dirichlet-Gaussian distribution. This approach permits a quantitative analysis of the compartmental composition of the brain and may be useful in the evaluation of patients with cerebral edema, hydrocephalus, and leukoencephalopathy.

Brain↗
PubMedDate not supplied

Interactive segmentation of cerebral gray matter, white matter, and CSF: photographic and MR images.

Digital photography of postmortem brain slices was compared with magnetic resonance imaging (MRI) for morphological analysis of human brain atrophy. In this study, we used two human brains obtained at autopsy: a cognitively defined nondemented control (70-yr-old male) and a demented Alzheimer's disease (AD) subject (82-yr-old female). For each of two brains, interactive manual image segmentation was performed by two observers on two image sets: (a) four coronal T1-weighted MR images (5 mm slices); and (b) four digitized photographic images from comparable rostrocaudal levels. Microcomputer image analysis software was used to measure the areas of three segmented cerebral compartments--gray matter (GM), white matter (WM) and CSF--for both image types. Resegmentation error was defined as the absolute difference between the areas derived from two segmentation trials divided by the value from trial 1 and multiplied by 100. This yielded the percent difference between the area measurements from the two trials. We found intra-observer agreement was better (error rates 1-18%) than inter-observer agreement (3-70%) with best agreement for WM and least for CSF, the smallest object class. MRI overestimated GM area relative to digitized photographs in the control but not the AD brain. The results define limitations of manual image segmentations and comparison of MRI with pathologic section photographic images.

Aged↗
PubMedDate not supplied

[Volumetric analysis of gray matter, white matter and cerebrospinal fluid space in schizophrenia].

Schizophrenia is characterized by diffuse brain abnormalities, some of them involving volumes of three intracranial compartments: gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF). Novel methods, such as Statistical Parametrical Mapping, provide an automated means of comparing structural features across high quality MRI scans and the measurement based on the principles of voxel based morphometry. For the purposes of the present study, we selected sex balanced group of young adults with recent onset illness to assess the effects of the illness on the volumes of compartments and also to minimize the effects of chronicity, medication, sex and aging. Sixty-four subjects were selected from a larger sample (inclusion criteria: age range 18-31). Thirty-one had DSM IV diagnosis of schizophrenia or schizoaffective disorder, 33 were controls. T1 weighted MRI images were acquired on two scanners (1.5T both): a) fast gradient echo sequence, FLASH, 40 msec repetition time, 5 ms echo time, 40 degree flip angle and b) turbo gradient echo, 12 msec repetition time, 4 msec echo time, 20 degree flip angle, 1 excitation). The resulting data set consisted of: a) 128 consecutive slices with 1.17 mm thickness and 256 x 256 pixels per slice and b) 160 consecutive slices of 1 mm thickness and 256 x 256 pixels per slice. All 64 images were processed by ANALZYE, and normalized and segmented by SPM99. Following the automatic segmentation of the images into the three intracranial compartments, volumetry was performed based on the principles of voxel analysis. Results were expressed relative to whole brain volume, and MANOVA analyses were performed to correct the confounding effects of MRI acquisition center differences and age difference between diagnostic groups. Young adults with recent onset schizophrenia had 6% reduction in GM volume and 14% increase in the volume of CSF, after all confounders were included into analyses (MANCOVA: p = 0.006 and 0.0002, respectively). No significant changes in WM volume were evident. In comparison to a few similar studies published recently, all results yielded similar scores regarding effects of recent onset illness and young adult population, thus confirming the reliability of the procedure. In conclusion, global neuropil reduction was discussed as a consequence of the cortical neurodevelopmental disgenesis. It was suggested that neuropil reduction i.e. synaptic and dendritic changes were to induce functional abnormalities and the expression of schizophrenia.

Adolescent↗
PubMed1994

Quantitation of grey matter, white matter, and cerebrospinal fluid from spin-echo magnetic resonance images using an artificial neural network technique.

An operator independent technique has been developed to quantitate the volume of white matter (WM), grey matter (GM), and cerebrospinal fluid (CSF) using spin-echo magnetic resonance images. Using skull stripped spin-echo images, CSF was removed using an automated thresholding technique. The bimodal histogram of the remaining images was used to train a perceptron and a single hidden layer neural network to output the percentage of GM and WM in the image. The output values were compared with those of a semiautomated technique employing a least square fitting technique [graduated nonconvexity algorithm (GNC)] applied to the bimodal histogram. This semiautomated technique allowed for intervention by the radiologist. Fourteen normal volunteers with eight contiguous slices each were analyzed. The individual percentages of WM, GM, and CSF of 40 slices from five subjects not used in the training set as well as the total percentages of GM, WM, and CSF in each individual were predicted using the two artificial network architectures. GM, WM, and CSF percentages were predicted within 7% for individual slices while total percentages of WM, GM, and CSF were computed accurately with an absolute error of less than 5% when compared to the semiautomated technique involving a trained neuroradiologist.

Adult↗
PubMed1998

Regional gray matter, white matter, and cerebrospinal fluid distributions in schizophrenic patients, their siblings, and controls.

BACKGROUND: Cortical gray matter volume reductions and cerebrospinal fluid (CSF) volume increases are robust correlates of schizophrenia, but their sources have not been established conclusively. METHODS: Structured diagnostic interviews and magnetic resonance imaging scans of the brain were obtained on 75 psychotic probands (63 with schizophrenia and 12 with schizoaffective disorder), ascertained so as to be representative of all such probands in a Helsinki, Finland, birth cohort; 60 of their nonpsychotic full siblings; and 56 demographically similar control subjects without a personal or family history of treated psychiatric morbidity. RESULTS: Patients with schizophrenia and their siblings exhibited significant reductions in cortical gray matter volume and significant increases in sulcal CSF volume compared with controls. The patients, but not their siblings, also exhibited significant reductions in white matter volume and significant increases in ventricular CSF volume. Regional effects were most robust when component volumes were expressed as percentages of overall regional volumes; in this case, for patient and sibling groups, gray matter volume reductions and sulcal CSF volume increases were significantly more pronounced in the frontal and temporal lobes than in the remainder of the brain. None of the group differences varied significantly by sex or hemisphere. CONCLUSIONS: Structural alterations of the cerebral cortex, particularly in the frontal and temporal lobes, are present in patients with schizophrenia and in some of their siblings without schizophrenia; such changes are thus likely to reflect genetic (or shared environmental) effects. Ventricular enlargement is unique to the clinical phenotype and is thus likely to be affected primarily by nonshared causative factors.

Adult↗
PubMed2002

Demonstration and distribution of tau-positive glial coiled body-like structures in white matter and white matter threads in early onset Alzheimer's disease.

The present report concerns the demonstration and distribution of tau-positive structures in the frontal and temporal white matter of five autopsy cases of early onset Alzheimer's disease (AD). The relationship between white matter lesions and tau positive structures was also investigated. Five early onset AD brains, which had not only unambiguous white matter lesions, but also no or rare atherosclerosis and minimal amyloid angiopathy, were examined. There were several tau-positive coiled body-like structures and many thread-like structures in the white matter, although previous reports showed only a few coiled bodies in the white matter in the AD brain. No relationship was found between the degree of each white matter lesion and number or distribution of tau-positive structures in the white matter. The results suggest that the AD brain has tau-positive structures in the white matter similar to some neurodegenarative brain diseases such as progressive supranuclear palsy, corticobasal degeneration, and dementia with grains. However, tau abnormalities may have fewer effects when they are located in white matter lesions in AD.

Age of Onset↗
PubMed2005

Relation between cerebrospinal fluid, gray matter and white matter changes in families with schizophrenia.

BACKGROUND: Gray matter reduction and ventricular enlargement belong to the best replicated findings in schizophrenia. Brain morphologic changes were also found in non-schizophrenic family members (FM). The intention of this study was to examine whether non-psychotic first-degree relatives reveal similar morphologic changes as schizophrenic patients and how state of genetic loading contribute to these abnormalities. METHODS: Forty-nine schizophrenic patients, 71 non-schizophrenic FM and 48 control subjects took part in this volumetric MRI study. All subjects were between 18 and 59 years old. Dependent variables were gray matter, white matter and total cerebrospinal fluid (CSF) volume, determined by SPM99 segmentation algorithm. As an important part of CSF lateral ventricle volume was determined manually by removing surrounding CSF areas. RESULTS: In schizophrenic patients compared to controls and non-schizophrenic FM total CSF volumes and lateral ventricles were increased. Gray and, to a lesser degree, white matter volumes were decreased as well. For CSF, gray and white matter there was no significant difference between uni- and multiple affected families. CSF correlated significantly negative with gray matter (r=-0.78) and, less intensive, with white matter (r=-0.40). There were negative correlations between gray and white matter volume as well (r=-0.26). These correlations were not significantly different between the diagnostic groups. CONCLUSION: CSF enlargement and gray matter reductions in schizophrenic patients compared to controls and non-affected FM seem to be interdependent findings. However, this correlation is independent of the factor diagnosis and is therefore not specific for schizophrenia.

Adult↗
PubMed2001

Brain atrophy in relapsing-remitting multiple sclerosis: fractional volumetric analysis of gray matter and white matter.

PURPOSE: To determine the fractional brain tissue volume changes in the gray matter and white matter of patients with relapsing-remitting multiple sclerosis (MS) and to correlate these measurements with clinical disability and total lesion load. MATERIALS AND METHODS: Thirty patients with relapsing-remitting MS and 25 healthy control subjects underwent magnetic resonance imaging. Fractional brain tissue volumes (tissue volume relative to total intracranial volume) were obtained from the total segmented gray matter and white matter in each group and were analyzed. RESULTS: The fractional volume of white matter versus that of gray matter was significantly lower (-6.4%) in patients with MS (P <.0001) than in control subjects. Neither gray matter nor white matter fractional volume measurements correlated with clinical disability in the patients with MS. CONCLUSION: Loss of brain parenchymal volume in patients with relapsing-remitting MS is predominantly confined to white matter. Analysis of fractional brain tissue volumes provides additional information useful in characterizing MS and may have potential in evaluating treatment strategies.

Adult↗
PubMed1982

Effects of neonatal undernutrition on the lipid composition of gray matter and white matter in rat brain.

Separate analyses were made of gray matter and white matter from rat brain after neonatal undernutrition. Newborn rats were redistributed into control, large-litter, and protein-deficient groups. Large litters had 16 rather than 8 pups with a dam. Protein-deficient dams were fed a 4%, instead of a 24%, casein diet. For controls at 21 days of age, the 2',3'-cyclic nucleotide-3'-phosphohydrolase activity was more than fivefold greater in white matter than in gray matter. Severe undernutrition (protein-deficient) gave 2',3'-cyclic nucleotide-3'-phosphohydrolase activities that were 36% lower in gray matter and 56% lower in white matter. Lipid galactose concentrations were 17% less than control in both gray matter and white matter. In protein-deficient white matter, phospholipid concentrations were 15% lower than control. Ethanolamine plasmalogens and phosphatidyl serine were affected most. Moderate nutrition (large litter) had no effect on 2',3'-cyclic nucleotide-3'-phosphohydrolase activity. A 14% deficit of galactolipids was the only difference from controls in large-litter white matter. In large-litter gray matter, phospholipid concentrations were 16% higher than controls. Nearly all glycerophospholipids, including plasmalogens, were affected. With the exception of the myelination markers, 2'3',-cyclic nucleotide-3'-phosphohydrolase and lipid galactose, the development of lipids in gray matter is almost completely spared from the effects of undernutrition. The primary effect of undernutrition is on myelination, especially in white matter.

Aging↗
PubMed1996

Cerebral gray matter and white matter volume deficits in adolescent girls with anorexia nervosa.

OBJECTIVES: This study was undertaken to determine whether the increased cerebrospinal fluid (CSF) volumes found in anorexia nervosa (AN) are the result of differences in gray matter or white matter volumes or both. METHODS: Thirteen adolescent girls with AN who were receiving inpatient care at a tertiary-care university children's hospital and eight healthy female control subjects were studied by using magnetic resonance imaging. Images were processed by means of software developed to classify all pixels as either CSF, gray matter, or white matter. Pixels of each class were then summed across all sections. RESULTS: The AN group had larger total CSF volumes in association with deficits in both total gray matter and total white matter volumes. Lowest reported body mass index was inversely correlated with total CSF volume and positively correlated with total gray matter volume. Urinary free cortisol levels were positively correlated with total CSF volume and inversely correlated with central gray matter volume. CONCLUSIONS: These findings add support to the view that the brain abnormalities found in AN are in large part the result of the effects of the illness. The extent to which these differences in gray matter and white matter volumes are reversible with recovery remains to be established.

Adolescent↗
PubMed1992

[Arterial hypertension and pathology of cerebral white matter].

White matter of the brain in 25 autopsy cases with the stroke and chronic cerebro-vascular pathology produced by arterial hypertension (AH) was studied morphologically. Focal and diffuse changes of the white matter were found against the background of the hypertonic angiopathy. These changes were represented by lacunar infarcts, foci of incomplete necrosis, perivascular encephalolysis, more seldom by small haemorrhages in combination with edema, cribriform lesions and widespread spongiosis of the white matter. Alterations of the cortex-medullary arteries, microcirculatory bed, disturbances of the dynamics of liquor and permeability of blood-brain barrier play the most important role in the white matter damage. The authors distinguish 3 forms of this damage. The complex of these alterations is regarded as a morphological substrate of a vascular dementia associated with AH.

Adult↗