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Volumetric Analysis (volumetric + analysis)
Selected AbstractsMRI Volumetric Analysis in Rasmussen Encephalitis: A Longitudinal StudyEPILEPSIA, Issue 2 2003Masanori Takeoka Summary: ,Purpose: Rasmussen encephalitis is a progressive inflammatory process with difficult-to-control focal or lateralized seizure activity, leading to hemispheric dysfunction and atrophy in advanced stages. Anatomic changes of atrophy may be subtle in earlier phases of the disease, and progressive changes on serial scans may be difficult to detect. We report a case of early-stage Rasmussen encephalitis with a relatively stable clinical course in whom we performed magnetic resonance imaging (MRI)-based volumetric analysis over an interval of 1 year, to assess for volumetric changes. Methods: Volumetric analysis was performed on two successive MRI scans obtained at age 5 and 6 years, by using the CARDVIEWS program (J Cogn Neurosci, 1996). The images were segmented into gray- and white-matter structures according to signal intensity of their borders semiautomatically, with manual corrections. The cerebral cortex was further subdivided into smaller parcellation units according to anatomic landmarks identifiable on MRI. Results: Stable left cerebral hemispheric atrophy and progressive atrophy in the left precentral gyrus, left inferior frontal gyrus, and left cerebellar atrophy were detected over the 1-year interval. Conclusions: Volumetric analysis enables early detection and quantification of anatomic changes, identification of focal involvement, and assists in determining the severity of disease and timing for surgical interventions such as hemispherectomy. [source] Both Global Gray Matter Volume and Regional Gray Matter Volume Negatively Correlate with Lifetime Alcohol Intake in Non,Alcohol-Dependent Japanese Men: A Volumetric Analysis and a Voxel-Based MorphometryALCOHOLISM, Issue 6 2006Yasuyuki Taki Background: Non,alcohol-dependent heavy drinkers, as well as alcohol-dependent individuals, show brain atrophy. The purpose of this study was to evaluate whether there are correlations between global and regional gray matter volumes and the lifetime alcohol intake using volumetric analysis and voxel-based morphometry (VBM) among Japanese non-alcohol,dependent male individuals. Methods: High-resolution three-dimensional magnetic resonance images were acquired from 405 Japanese non-alcohol,dependent male individuals. The collected images were normalized, segmented for volumetric analysis, and additionally smoothed for VBM. For volumetric analysis, the partial correlation coefficient was estimated between the gray matter ratio, which represents the percentage of gray matter volume in the intracranial volume, and the lifetime alcohol intake adjusted for the age of each subject. Multiple regression analysis was performed among regional gray matter volume, lifetime alcohol intake, and age using VBM. Results: Volumetric analysis revealed that gray matter ratio showed a negative correlation with the lifetime alcohol intake adjusted for age (p=0.059, partial correlation coefficient=,0.091). The VBM revealed that the gray matter volumes of the bilateral middle frontal gyri showed a significant negative correlation with the lifetime alcohol intake adjusted for age and systolic blood pressure (left side, p=0.006, Z=4.77; right side, p=0.023, Z=4.45, and p=0.046, Z=4.27). Conclusions: Our study suggests that non-alcohol,dependent Japanese male individuals show that both global gray matter volume and regional gray matter volume have negative correlations with the lifetime alcohol intake. Our study may contribute to clarifying the mechanism underlying the brain structural changes because of alcohol influence in healthy non-alcohol,dependent individuals. [source] Gender-Related Differences in Coronary Artery Dimensions: A Volumetric AnalysisCLINICAL CARDIOLOGY, Issue 2 2010Jennifer A. Dickerson MD Abstract Background Women consistently have poorer revascularization outcomes and more coronary vascular complications compared to men. This has been attributed to smaller coronary arteries, though limited data exist to support this assumption. Hypothesis By using volumetric data obtained from multidetector cardiovascular computed tomography (CCT), we sought to determine to what extent gender influences coronary artery dimensions and test the hypothesis that women would have smaller coronary dimensions even after normalizing for body surface area and cardiac mass. Methods CCT examinations completed on a 64-slice scanner were identified from a university cardiovascular database. Data sets from 50 women and 44 men without coronary artery disease were selected for analysis. Cross-sectional areas of proximal and distal segments of the left anterior descending (LAD), circumflex (LCx), and right coronary artery (RCA) were measured, blinded to patient gender. Measurements were compared using 2-sample t tests and linear regression analysis techniques accounting for body surface area (BSA) and left ventricular (LV) mass. Results Analysis of cross-sectional coronary artery areas, unadjusted for BSA and LV mass showed smaller coronary artery size in women compared to men in the proximal portion of both the LAD (P = .01) and RCA (P = .002), but no significant difference in the remaining coronary segments. Conclusion Gender significantly impacts proximal LAD and RCA size. Differences in coronary artery dimensions may explain some, but not all excess gender-related risk with coronary artery revascularization, underscoring the importance of considering multiple contributing factors. Copyright © 2010 Wiley Periodicals, Inc. [source] MRI Volumetric Analysis in Rasmussen Encephalitis: A Longitudinal StudyEPILEPSIA, Issue 2 2003Masanori Takeoka Summary: ,Purpose: Rasmussen encephalitis is a progressive inflammatory process with difficult-to-control focal or lateralized seizure activity, leading to hemispheric dysfunction and atrophy in advanced stages. Anatomic changes of atrophy may be subtle in earlier phases of the disease, and progressive changes on serial scans may be difficult to detect. We report a case of early-stage Rasmussen encephalitis with a relatively stable clinical course in whom we performed magnetic resonance imaging (MRI)-based volumetric analysis over an interval of 1 year, to assess for volumetric changes. Methods: Volumetric analysis was performed on two successive MRI scans obtained at age 5 and 6 years, by using the CARDVIEWS program (J Cogn Neurosci, 1996). The images were segmented into gray- and white-matter structures according to signal intensity of their borders semiautomatically, with manual corrections. The cerebral cortex was further subdivided into smaller parcellation units according to anatomic landmarks identifiable on MRI. Results: Stable left cerebral hemispheric atrophy and progressive atrophy in the left precentral gyrus, left inferior frontal gyrus, and left cerebellar atrophy were detected over the 1-year interval. Conclusions: Volumetric analysis enables early detection and quantification of anatomic changes, identification of focal involvement, and assists in determining the severity of disease and timing for surgical interventions such as hemispherectomy. [source] Volumetric analysis of extraction sockets using cone beam computed tomography: a pilot study on ex vivo jaw boneJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2007Jimoh Olubanwo Agbaje Abstract Aim: The aim of this study was to determine the accuracy of volumetric analysis of extraction sockets using cone beam computed tomography (CBCT). Material and Methods: The volume of 40 dental alveoli in nine dry skull specimens (four mandibles and five maxillae) was determined by measuring the volume of the tooth socket impression using the water displacement technique. This was considered as the gold standard. Then, the tooth socket was scanned with CBCT and data were uploaded in the semi-automated Livewire® segmentation software. The software segments the tooth socket in consecutive 1 mm-thick two-dimensional slices. After segmentation, the total volume of the delineated socket was computed. The statistical difference between direct volumetric measurements and those obtained with CBCT imaging was assessed using the Student paired t -test. Result: The mean socket volume of the skull specimens was 227±91 mm3 when obtained by direct measurement and 225±90 mm3 when obtained by CBCT imaging. Student paired t -test showed no significant differences between both volume measurements (p>0.1). Conclusions: CBCT permits imaging of anatomical structures in three planes and allows for reliable volume estimates. The results should be verified in clinical circumstances and might have potential applicability for evaluation of extraction socket healing under different conditions. [source] Interstudy reproducibility of three-dimensional volume-selective fast spin echo magnetic resonance for quantifying carotid artery wall volumeJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2005Anitha Varghese BSc Abstract Purpose To assess the interstudy reproducibility of a three-dimensional volume-selective, fast spin echo (FSE) magnetic resonance technique for the assessment of carotid artery wall volume, which is a marker for total carotid plaque volume. Materials and Methods Interstudy reproducibility was evaluated in 10 subjects with evidence of carotid artery atherosclerotic disease on carotid Doppler ultrasonography. Subjects were scanned twice with an interscan time of one hour to four days. The carotid artery was imaged in cross-section, and the total carotid arterial wall volume (TWV) was calculated by subtraction of the total carotid lumen volume from the total outer carotid vessel volume. Results The mean carotid TWV for the scans was 741 and 734 mm3, respectively, with no significant difference (mean difference 7 mm3; P = 0.5). The time for each study was approximately 20 minutes. The standard deviation of the differences between the measurements was 33 mm3, yielding an interstudy coefficient of variation of 4.4%. Sample size calculations showed that 16 patients would enable this difference in plaque volume over time to be detected with 80% power at a P value of 0.05. Conclusion Volumetric analysis with CMR of carotid artery plaques using a three-dimensional volume-selective FSE is efficient with good interstudy reproducibility, and is well suited for longitudinal studies of progression of carotid atheroma with reasonable sample sizes. J. Magn. Reson. Imaging 2005;21:187,191. © 2005 Wiley-Liss, Inc. [source] Both Global Gray Matter Volume and Regional Gray Matter Volume Negatively Correlate with Lifetime Alcohol Intake in Non,Alcohol-Dependent Japanese Men: A Volumetric Analysis and a Voxel-Based MorphometryALCOHOLISM, Issue 6 2006Yasuyuki Taki Background: Non,alcohol-dependent heavy drinkers, as well as alcohol-dependent individuals, show brain atrophy. The purpose of this study was to evaluate whether there are correlations between global and regional gray matter volumes and the lifetime alcohol intake using volumetric analysis and voxel-based morphometry (VBM) among Japanese non-alcohol,dependent male individuals. Methods: High-resolution three-dimensional magnetic resonance images were acquired from 405 Japanese non-alcohol,dependent male individuals. The collected images were normalized, segmented for volumetric analysis, and additionally smoothed for VBM. For volumetric analysis, the partial correlation coefficient was estimated between the gray matter ratio, which represents the percentage of gray matter volume in the intracranial volume, and the lifetime alcohol intake adjusted for the age of each subject. Multiple regression analysis was performed among regional gray matter volume, lifetime alcohol intake, and age using VBM. Results: Volumetric analysis revealed that gray matter ratio showed a negative correlation with the lifetime alcohol intake adjusted for age (p=0.059, partial correlation coefficient=,0.091). The VBM revealed that the gray matter volumes of the bilateral middle frontal gyri showed a significant negative correlation with the lifetime alcohol intake adjusted for age and systolic blood pressure (left side, p=0.006, Z=4.77; right side, p=0.023, Z=4.45, and p=0.046, Z=4.27). Conclusions: Our study suggests that non-alcohol,dependent Japanese male individuals show that both global gray matter volume and regional gray matter volume have negative correlations with the lifetime alcohol intake. Our study may contribute to clarifying the mechanism underlying the brain structural changes because of alcohol influence in healthy non-alcohol,dependent individuals. [source] A comprehensive volumetric analysis of the cerebellum in children and adolescents with autism spectrum disorderAUTISM RESEARCH, Issue 5 2009Julia A. Scott Abstract Magnetic resonance imaging (MRI) and postmortem neuropathological studies have implicated the cerebellum in the pathophysiology of autism. Controversy remains, however, concerning the nature and the consistency of cerebellar alterations. MRI studies of the cross-sectional area of the vermis have found both decreases and no difference in autism groups. Volumetric analysis of the vermis, which is less prone to "plane of section artifacts" may provide a more reliable assessment of size differences but few such studies exist in the literature. Here we present the results of a volumetric analysis of the structure of the whole cerebellum and its components in children and adolescents with autism spectrum disorders. Structural MRI's were acquired from 62 male participants (7.5 to 18.5 years-old) who met criteria for the following age-matched diagnostic groups: low functioning autism, high functioning autism (HFA), Asperger syndrome, and typically developing children. When compared to controls, the midsagittal area of the vermis, or of subgroups of lobules, was not reduced in any of the autism groups. However, we did find that total vermis volume was decreased in the combined autism group. When examined separately, the vermis of only the HFA group was significantly reduced compared to typically developing controls. Neither IQ nor age predicted the size of the vermis within the autism groups. There were no differences in the volume of individual vermal lobules or cerebellar hemispheres. These findings are discussed in relation to the pathology of autism and to the fairly common alterations of vermal morphology in various neurodevelopmental disorders. [source] Quantification of red myotomal muscle volume and geometry in the shortfin mako shark (Isurus oxyrinchus) and the salmon shark (Lamna ditropis) using T1 -weighted magnetic resonance imagingJOURNAL OF MORPHOLOGY, Issue 4 2007Cameron N. Perry Abstract T1 -weighted magnetic resonance imaging (MRI) in conjunction with image and segmentation analysis (i.e., the process of digitally partitioning tissues based on specified MR image characteristics) was evaluated as a noninvasive alternative for differentiating muscle fiber types and quantifying the amounts of slow, red aerobic muscle in the shortfin mako shark (Isurus oxyrinchus) and the salmon shark (Lamna ditropis). MRI-determinations of red muscle quantity and position made for the mid-body sections of three mako sharks (73.5,110 cm fork length, FL) are in close agreement (within the 95% confidence intervals) with data obtained for the same sections by the conventional dissection method involving serial cross-sectioning and volumetric analyses, and with previously reported findings for this species. The overall distribution of salmon shark red muscle as a function of body fork length was also found to be consistent with previously acquired serial dissection data for this species; however, MR imaging revealed an anterior shift in peak red muscle cross-sectional area corresponding to an increase in body mass. Moreover, MRI facilitated visualization of the intact and anatomically correct relationship of tendon linking the red muscle and the caudal peduncle. This study thus demonstrates that MRI is effective in acquiring high-resolution three-dimensional digital data with high contrast between different fish tissue types. Relative to serial dissection, MRI allows more precise quantification of the position, volume, and other details about the types of muscle within the fish myotome, while conserving specimen structural integrity. J. Morphol., 2007. © 2007 Wiley-Liss, Inc. [source] MRI Volumetric Analysis in Rasmussen Encephalitis: A Longitudinal StudyEPILEPSIA, Issue 2 2003Masanori Takeoka Summary: ,Purpose: Rasmussen encephalitis is a progressive inflammatory process with difficult-to-control focal or lateralized seizure activity, leading to hemispheric dysfunction and atrophy in advanced stages. Anatomic changes of atrophy may be subtle in earlier phases of the disease, and progressive changes on serial scans may be difficult to detect. We report a case of early-stage Rasmussen encephalitis with a relatively stable clinical course in whom we performed magnetic resonance imaging (MRI)-based volumetric analysis over an interval of 1 year, to assess for volumetric changes. Methods: Volumetric analysis was performed on two successive MRI scans obtained at age 5 and 6 years, by using the CARDVIEWS program (J Cogn Neurosci, 1996). The images were segmented into gray- and white-matter structures according to signal intensity of their borders semiautomatically, with manual corrections. The cerebral cortex was further subdivided into smaller parcellation units according to anatomic landmarks identifiable on MRI. Results: Stable left cerebral hemispheric atrophy and progressive atrophy in the left precentral gyrus, left inferior frontal gyrus, and left cerebellar atrophy were detected over the 1-year interval. Conclusions: Volumetric analysis enables early detection and quantification of anatomic changes, identification of focal involvement, and assists in determining the severity of disease and timing for surgical interventions such as hemispherectomy. [source] Preparation and Certification of High-Grade Gold Ore Reference Materials (GAu 19-22)GEOSTANDARDS & GEOANALYTICAL RESEARCH, Issue 1 2001Tiexin Gu materiau de référence certifié; gisement d 'or,GAu 19-22,IGGE,valeurs certifiées Two types of gold deposit with both good homogeneity and a high-grade of gold were selected to prepare four gold ore reference materials (GAu-19,GAu-20,GAu-21 and GAu-22) by the Institute of Geophysical and Geochemical Exploration (IGGE),China. Seven laboratories participated in the certification programme. Volumetric methods for GAu19-21 and atomic absorption spectrometry for GAu-22 were used for the homogeneity testing,the coefficient of variation being found to be less than 3%. After sample digestion and preconcentration,the samples were analysed by flame atomic absorption spectrometry (AAS),colorimetry,neutron activation analysis (NAA)and volumetric analysis. The certified values for the gold concentration in GAu19-22 are 18.3 ,g g -1, 32.3 ,g g -1, 53.0 ,g g -1 and 5.72 ,g g -1,respectively. Deux types de gisements d'or, présentant à la foisune bonne homogénéité et une teneur élevée en or, ont été sélectionnés par l'Institut d 'Exploration Géophysique et Géochimique de Chine (IGGE)afin de préparer quatre matériaux de référence pour l'or (GAu-19,GAu-20,GAu-21 et Gau-22). Sept laboratoires ont participé au programme de certification. Des méthodes volumétriques (GAu-19-21)et de spectrométrie par absorption atomique (GAu 22)ont été utilisées pour tester l'homogénéité de ces échantillons;les coefficients de variation se sont révélés inférieurs à 3%.Après la mise en solution et la préconcentration des échantillons,ceux-ci ont eté analysés par spectrométrie d 'absorption atomique (AAS), colorimétrie,activation neutronique (NAA)et analyse volumétrique.Les valeurs certifiées pour la concentration en or de GAu19-22 sont respectivement de 18.3 ,g.g -1,32.3 ,g g -1, 53.0 ,g g -1 et 5.72 ,g g -1. [source] Detecting corpus callosum abnormalities in autism subtype using planar conformal mappingINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 2 2010Ye Duan Abstract A number of studies have documented that autism has a neurobiological basis, but the anatomical extent of these neurobiological abnormalities is largely unknown. In this paper, we apply advanced computational techniques to extract 3D models of the corpus callosum (CC) and subsequently analyze local shape variations in a homogeneous group of autistic children. Besides the traditional volumetric analysis, we explore additional phenotypic traits based on the oriented bounding rectangle of the CC. In shape analysis, a new conformal parameterization is applied in our shape analysis work, which maps the surface onto a planar domain. Surface matching among different individual meshes is achieved by aligning the planar domains of individual meshes. Shape differences of the CC between autistic patients and the controls are computed using Hotelling T2 two-sample metric followed by a permutation test. The raw and corrected p -values are shown in the results. Additional visualization of the group difference is provided via mean difference map. Copyright © 2009 John Wiley & Sons, Ltd. [source] Volumetric analysis of extraction sockets using cone beam computed tomography: a pilot study on ex vivo jaw boneJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2007Jimoh Olubanwo Agbaje Abstract Aim: The aim of this study was to determine the accuracy of volumetric analysis of extraction sockets using cone beam computed tomography (CBCT). Material and Methods: The volume of 40 dental alveoli in nine dry skull specimens (four mandibles and five maxillae) was determined by measuring the volume of the tooth socket impression using the water displacement technique. This was considered as the gold standard. Then, the tooth socket was scanned with CBCT and data were uploaded in the semi-automated Livewire® segmentation software. The software segments the tooth socket in consecutive 1 mm-thick two-dimensional slices. After segmentation, the total volume of the delineated socket was computed. The statistical difference between direct volumetric measurements and those obtained with CBCT imaging was assessed using the Student paired t -test. Result: The mean socket volume of the skull specimens was 227±91 mm3 when obtained by direct measurement and 225±90 mm3 when obtained by CBCT imaging. Student paired t -test showed no significant differences between both volume measurements (p>0.1). Conclusions: CBCT permits imaging of anatomical structures in three planes and allows for reliable volume estimates. The results should be verified in clinical circumstances and might have potential applicability for evaluation of extraction socket healing under different conditions. [source] Both Global Gray Matter Volume and Regional Gray Matter Volume Negatively Correlate with Lifetime Alcohol Intake in Non,Alcohol-Dependent Japanese Men: A Volumetric Analysis and a Voxel-Based MorphometryALCOHOLISM, Issue 6 2006Yasuyuki Taki Background: Non,alcohol-dependent heavy drinkers, as well as alcohol-dependent individuals, show brain atrophy. The purpose of this study was to evaluate whether there are correlations between global and regional gray matter volumes and the lifetime alcohol intake using volumetric analysis and voxel-based morphometry (VBM) among Japanese non-alcohol,dependent male individuals. Methods: High-resolution three-dimensional magnetic resonance images were acquired from 405 Japanese non-alcohol,dependent male individuals. The collected images were normalized, segmented for volumetric analysis, and additionally smoothed for VBM. For volumetric analysis, the partial correlation coefficient was estimated between the gray matter ratio, which represents the percentage of gray matter volume in the intracranial volume, and the lifetime alcohol intake adjusted for the age of each subject. Multiple regression analysis was performed among regional gray matter volume, lifetime alcohol intake, and age using VBM. Results: Volumetric analysis revealed that gray matter ratio showed a negative correlation with the lifetime alcohol intake adjusted for age (p=0.059, partial correlation coefficient=,0.091). The VBM revealed that the gray matter volumes of the bilateral middle frontal gyri showed a significant negative correlation with the lifetime alcohol intake adjusted for age and systolic blood pressure (left side, p=0.006, Z=4.77; right side, p=0.023, Z=4.45, and p=0.046, Z=4.27). Conclusions: Our study suggests that non-alcohol,dependent Japanese male individuals show that both global gray matter volume and regional gray matter volume have negative correlations with the lifetime alcohol intake. Our study may contribute to clarifying the mechanism underlying the brain structural changes because of alcohol influence in healthy non-alcohol,dependent individuals. [source] A comprehensive volumetric analysis of the cerebellum in children and adolescents with autism spectrum disorderAUTISM RESEARCH, Issue 5 2009Julia A. Scott Abstract Magnetic resonance imaging (MRI) and postmortem neuropathological studies have implicated the cerebellum in the pathophysiology of autism. Controversy remains, however, concerning the nature and the consistency of cerebellar alterations. MRI studies of the cross-sectional area of the vermis have found both decreases and no difference in autism groups. Volumetric analysis of the vermis, which is less prone to "plane of section artifacts" may provide a more reliable assessment of size differences but few such studies exist in the literature. Here we present the results of a volumetric analysis of the structure of the whole cerebellum and its components in children and adolescents with autism spectrum disorders. Structural MRI's were acquired from 62 male participants (7.5 to 18.5 years-old) who met criteria for the following age-matched diagnostic groups: low functioning autism, high functioning autism (HFA), Asperger syndrome, and typically developing children. When compared to controls, the midsagittal area of the vermis, or of subgroups of lobules, was not reduced in any of the autism groups. However, we did find that total vermis volume was decreased in the combined autism group. When examined separately, the vermis of only the HFA group was significantly reduced compared to typically developing controls. Neither IQ nor age predicted the size of the vermis within the autism groups. There were no differences in the volume of individual vermal lobules or cerebellar hemispheres. These findings are discussed in relation to the pathology of autism and to the fairly common alterations of vermal morphology in various neurodevelopmental disorders. [source] | ||||||||||