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1

Economic Analysis. Volume V. Course Segments 65-79.  

ERIC Educational Resources Information Center

|The fifth volume of the multimedia, individualized course in economic analysis produced for the United States Naval Academy covers segments 65-79 of the course. Included in the volume are discussions of monopoly markets, monopolistic competition, oligopoly markets, and the theory of factor demand and supply. Other segments of the course, the…

Sterling Inst., Washington, DC. Educational Technology Center.

2

Morphological segmentation and partial volume analysis for volumetry of solid pulmonary lesions in thoracic CT scans.  

PubMed

Volumetric growth assessment of pulmonary lesions is crucial to both lung cancer screening and oncological therapy monitoring. While several methods for small pulmonary nodules have previously been presented, the segmentation of larger tumors that appear frequently in oncological patients and are more likely to be complexly interconnected with lung morphology has not yet received much attention. We present a fast, automated segmentation method that is based on morphological processing and is suitable for both small and large lesions. In addition, the proposed approach addresses clinical challenges to volume assessment such as variations in imaging protocol or inspiration state by introducing a method of segmentation-based partial volume analysis (SPVA) that follows on the segmentation procedure. Accuracy and reproducibility studies were performed to evaluate the new algorithms. In vivo interobserver and interscan studies on low-dose data from eight clinical metastasis patients revealed that clinically significant volume change can be detected reliably and with negligible computation time by the presented methods. In addition, phantom studies were conducted. Based on the segmentation performed with the proposed method, the performance of the SPVA volumetry method was compared with the conventional technique on a phantom that was scanned with different dosages and reconstructed with varying parameters. Both systematic and absolute errors were shown to be reduced substantially by the SPVA method. The method was especially successful in accounting for slice thickness and reconstruction kernel variations, where the median error was more than halved in comparison to the conventional approach. PMID:16608058

Kuhnigk, Jan-Martin; Dicken, Volker; Bornemann, Lars; Bakai, Annemarie; Wormanns, Dag; Krass, Stefan; Peitgen, Heinz-Otto

2006-04-01

3

Applicability of segmental bioelectrical impedance analysis for predicting trunk skeletal muscle volume.  

PubMed

This study aimed to investigate the validity of using segmental bioelectrical impedance (BI) analysis for estimating skeletal muscle volume (MV) in the trunk, defined as the body segment from the acromion process to the greater trochanter. Using a magnetic resonance imaging (MRI) method, the trunk MV was determined in 28 men (19 approximately 34 yr), divided into validation (n = 20) and cross-validation (n = 8) groups, and used as a reference (MV(MRI)). For BI measurements of the trunk, the source electrodes were placed at the dorsal surface of the third metacarpal bone of both hands and the dorsal surface of the third metatarsal bone of both feet, and the detector electrodes were placed at the acromion process of both shoulders and the greater trochanter of both femurs. Using this arrangement, the BI values of five parts of the trunk, both sides of the upper region, the middle region, and both sides of the lower region, were obtained and then used to calculate the whole trunk BI value and BI index (BI index(TR)). In the validation group, a simple regression analysis of the relationship between BI index(TR) and MV(MRI) showed a significant correlation between the two variables (r = 0.884, P < 0.05) and produced a prediction equation with a SE of estimation of 1,020.3 cm3 (8.5%). In the validation and cross-validation groups, there were no significant differences between the measured and estimated MV without systematic errors. These findings indicate that the segmental BI analysis employed in the present study can be used to estimate trunk MV. PMID:16210443

Ishiguro, Noriko; Kanehisa, Hiroaki; Miyatani, Masae; Masuo, Yoshihisa; Fukunaga, Tetsuo

2005-10-06

4

Volume analysis of treatment response of head and neck lesions using 3D level set segmentation  

NASA Astrophysics Data System (ADS)

A computerized system for segmenting lesions in head and neck CT scans was developed to assist radiologists in estimation of the response to treatment of malignant lesions. The system performs 3D segmentations based on a level set model and uses as input an approximate bounding box for the lesion of interest. In this preliminary study, CT scans from a pre-treatment exam and a post one-cycle chemotherapy exam of 13 patients containing head and neck neoplasms were used. A radiologist marked 35 temporal pairs of lesions. 13 pairs were primary site cancers and 22 pairs were metastatic lymph nodes. For all lesions, a radiologist outlined a contour on the best slice on both the pre- and post treatment scans. For the 13 primary lesion pairs, full 3D contours were also extracted by a radiologist. The average pre- and post-treatment areas on the best slices for all lesions were 4.5 and 2.1 cm2, respectively. For the 13 primary site pairs the average pre- and post-treatment primary lesions volumes were 15.4 and 6.7 cm3 respectively. The correlation between the automatic and manual estimates for the pre-to-post-treatment change in area for all 35 pairs was r=0.97, while the correlation for the percent change in area was r=0.80. The correlation for the change in volume for the 13 primary site pairs was r=0.89, while the correlation for the percent change in volume was r=0.79. The average signed percent error between the automatic and manual areas for all 70 lesions was 11.0+/-20.6%. The average signed percent error between the automatic and manual volumes for all 26 primary lesions was 37.8+/-42.1%. The preliminary results indicate that the automated segmentation system can reliably estimate tumor size change in response to treatment relative to radiologist's hand segmentation.

Hadjiiski, Lubomir; Street, Ethan; Sahiner, Berkman; Gujar, Sachin; Ibrahim, Mohannad; Chan, Heang-Ping; Mukherji, Suresh K.

2008-04-01

5

Fully Automated Prostate Segmentation on MRI: Comparison With Manual Segmentation Methods and Specimen Volumes.  

PubMed

OBJECTIVE. The objective of our study was to compare calculated prostate volumes derived from tridimensional MR measurements (ellipsoid formula), manual segmentation, and a fully automated segmentation system as validated by actual prostatectomy specimens. MATERIALS AND METHODS. Ninety-eight consecutive patients (median age, 60.6 years; median prostate-specific antigen [PSA] value, 6.85 ng/mL) underwent triplane T2-weighted MRI on a 3-T magnet with an endorectal coil while undergoing diagnostic workup for prostate cancer. Prostate volume estimates were determined using the formula for ellipsoid volume based on tridimensional measurements, manual segmentation of triplane MRI, and automated segmentation based on normalized gradient fields cross-correlation and graph-search refinement. Estimates of prostate volume based on ellipsoid volume, manual segmentation, and automated segmentation were compared with prostatectomy specimen volumes. Prostate volume estimates were compared using the Pearson correlation coefficient and linear regression analysis. The Dice similarity coefficient was used to quantify spatial agreement between manual segmentation and automated segmentation. RESULTS. The Pearson correlation coefficient revealed strong positive correlation between prostatectomy specimen volume and prostate volume estimates derived from manual segmentation (R = 0.89-0.91, p < 0.0001) and automated segmentation (R = 0.88-0.91, p < 0.0001). No difference was observed between manual segmentation and automated segmentation. Mean partial and full Dice similarity coefficients of 0.92 and 0.89, respectively, were achieved for axial automated segmentation. CONCLUSION. Prostate volume estimates obtained with a fully automated 3D segmentation tool based on normalized gradient fields cross-correlation and graph-search refinement can yield highly accurate prostate volume estimates in a clinically relevant time of 10 seconds. This tool will assist in developing a broad range of applications including routine prostate volume estimations, image registration, biopsy guidance, and decision support systems. PMID:24147502

Turkbey, Baris; Fotin, Sergei V; Huang, Robert J; Yin, Yin; Daar, Dagane; Aras, Omer; Bernardo, Marcelino; Garvey, Brian E; Weaver, Juanita; Haldankar, Hrishikesh; Muradyan, Naira; Merino, Maria J; Pinto, Peter A; Periaswamy, Senthil; Choyke, Peter L

2013-11-01

6

Volume analysis of treatment response of head and neck lesions using 3D level set segmentation  

Microsoft Academic Search

A computerized system for segmenting lesions in head and neck CT scans was developed to assist radiologists in estimation of the response to treatment of malignant lesions. The system performs 3D segmentations based on a level set model and uses as input an approximate bounding box for the lesion of interest. In this preliminary study, CT scans from a pre-treatment

Lubomir Hadjiiski; Berkman Sahiner; Sachin Gujar; Mohannad Ibrahim; Heang-Ping Chan; Suresh K. Mukherji

2008-01-01

7

Misclassified Tissue Volumes in Alzheimer Disease Patients With White Matter Hyperintensities Importance of Lesion Segmentation Procedures for Volumetric Analysis  

Microsoft Academic Search

Background and Purpose—MRI-based quantification of gray and white matter volume is common in studies involving elderly patient populations. The aim of the present study was to describe the effects of not accounting for subcortical white matter hyperintensities (WMH) on tissue volumes in Alzheimer Disease patients with varying degrees of WMH (mild: n19, moderate: n22, severe: n18). Methods—An automated tissue segmentation

Naama Levy-Cooperman; Joel Ramirez; Nancy J. Lobaugh; Sandra E. Black

2010-01-01

8

PET functional volume segmentation: a robustness study  

Microsoft Academic Search

Current state of the art algorithms for functional volume segmentation in PET images for diagnosis, patients follow-up or radiotherapy treatment planning consist of adaptive threshold approaches. We have developed an unsupervised Bayesian segmentation algorithm for tumors in PET, namely the FLAB (for Fuzzy Locally Adaptive Bayesian) algorithm, that was previously validated on simulated images and then successfully extended and applied

M. Hatt; P. Bailly; A. Turzo; C. Roux; D. Visvikis

2008-01-01

9

Interactive segmentation of anatomical structures within digital volumes  

Microsoft Academic Search

In this communication, the authors give the first results of a geometrical modelling approach they have developed for representing anatomical structures. First, the authors describe briefly the main features of this approach which combines volumetric analysis and surface modelling. Its first step is an interactive segmentation of digital volumes: the authors introduce an original method to accurately perform this segmentation.

K. Malkani; Bmo Nazarian; Jean Sequeira

1996-01-01

10

Cerebral Blood Volume Analysis in Glioblastomas Using Dynamic Susceptibility Contrast-Enhanced Perfusion MRI: A Comparison of Manual and Semiautomatic Segmentation Methods  

PubMed Central

Purpose To compare the reproducibilities of manual and semiautomatic segmentation method for the measurement of normalized cerebral blood volume (nCBV) using dynamic susceptibility contrast-enhanced (DSC) perfusion MR imaging in glioblastomas. Materials and Methods Twenty-two patients (11 male, 11 female; 27 tumors) with histologically confirmed glioblastoma (WHO grade IV) were examined with conventional MR imaging and DSC imaging at 3T before surgery or biopsy. Then nCBV (means and standard deviations) in each mass was measured using two DSC MR perfusion analysis methods including manual and semiautomatic segmentation method, in which contrast-enhanced (CE)-T1WI and T2WI were used as structural imaging. Intraobserver and interobserver reproducibility were assessed according to each perfusion analysis method or each structural imaging. Interclass correlation coefficient (ICC), Bland-Altman plot, and coefficient of variation (CV) were used to evaluate reproducibility. Results Intraobserver reproducibilities on CE-T1WI and T2WI were ICC of 0.74–0.89 and CV of 20.39–36.83% in manual segmentation method, and ICC of 0.95–0.99 and CV of 8.53–16.19% in semiautomatic segmentation method, repectively. Interobserver reproducibilites on CE-T1WI and T2WI were ICC of 0.86–0.94 and CV of 19.67–35.15% in manual segmentation method, and ICC of 0.74–1.0 and CV of 5.48–49.38% in semiautomatic segmentation method, respectively. Bland-Altman plots showed a good correlation with ICC or CV in each method. The semiautomatic segmentation method showed higher intraobserver and interobserver reproducibilities at CE-T1WI-based study than other methods. Conclusion The best reproducibility was found using the semiautomatic segmentation method based on CE-T1WI for structural imaging in the measurement of the nCBV of glioblastomas.

Jung, Seung Chai; Choi, Seung Hong; Yeom, Jeong A.; Kim, Ji-Hoon; Ryoo, Inseon; Kim, Soo Chin; Shin, Hwaseon; Lee, A. Leum; Yun, Tae Jin; Park, Chul-Kee; Sohn, Chul-Ho; Park, Sung-Hye

2013-01-01

11

Multiple layer segmentation and analysis in three-dimensional spectral-domain optical coherence tomography volume scans.  

PubMed

Spectral-domain optical coherence tomography (SD-OCT) is a three-dimensional imaging technique that allows direct visualization of retinal morphology and architecture. The various retinal layers may be affected differentially by various diseases. An automated graph search algorithm is developed to sequentially segment 11 retinal surfaces in SD-OCT volumes using a three-stage approach. In stage 1, the four most easily discernible and/or distinct surfaces are identified in four-times-downsampled images and are used as a priori information to limit the graph search for the other surfaces in stage 2. Eleven surfaces were then detected in two-times-downsampled images in stage 2, and refined in the original images in stage 3 using the graph search integrating the estimated morphological shape models. Twenty macular SD-OCT volume scans from 20 normal subjects are used in this initial study. The overall mean and absolute mean differences in border positions between the automated and manual segmentation for the 11 surfaces are -0.20 ± 0.53 voxels (-0.76 ± 2.06 ?m) and 0.82 ± 0.64 voxels (3.19 ± 2.46 ?m), respectively. Intensity/reflectivity and thickness properties in various retinal layers are also investigated. This investigation in normal subjects may provide a comparative reference for subsequent adaptations in eyes with diseases. PMID:23843084

Hu, Zhihong; Wu, Xiaodong; Hariri, Amirhossein; Sadda, Srinivas R

2013-07-01

12

Active volume models for medical image segmentation.  

PubMed

In this paper, we propose a novel predictive model, active volume model (AVM), for object boundary extraction. It is a dynamic "object" model whose manifestation includes a deformable curve or surface representing a shape, a volumetric interior carrying appearance statistics, and an embedded classifier that separates object from background based on current feature information. The model focuses on an accurate representation of the foreground object's attributes, and does not explicitly represent the background. As we will show, however, the model is capable of reasoning about the background statistics thus can detect when is change sufficient to invoke a boundary decision. When applied to object segmentation, the model alternates between two basic operations: 1) deforming according to current region of interest (ROI), which is a binary mask representing the object region predicted by the current model, and 2) predicting ROI according to current appearance statistics of the model. To further improve robustness and accuracy when segmenting multiple objects or an object with multiple parts, we also propose multiple-surface active volume model (MSAVM), which consists of several single-surface AVM models subject to high-level geometric spatial constraints. An AVM's deformation is derived from a linear system based on finite element method (FEM). To keep the model's surface triangulation optimized, surface remeshing is derived from another linear system based on Laplacian mesh optimization (LMO). Thus efficient optimization and fast convergence of the model are achieved by solving two linear systems. Segmentation, validation and comparison results are presented from experiments on a variety of 2-D and 3-D medical images. PMID:21118771

Shen, Tian; Li, Hongsheng; Huang, Xiaolei

2010-11-29

13

Effect of volume changes on segmental relaxation in siloxane polymers  

Microsoft Academic Search

From dielectric relaxation and equation-of-state measurements on polymethylphenylsiloxane and polymethyltolylsiloxane, the relative contributions of volume and thermal energy to the temperature dependence of the segmental relaxation times are quantified. In both polymers, volume exerts a substantial effect, being almost as significant as thermal energy. A possible consequence of this prominent role of volume in governing the segmental dynamics is the

M. Paluch; R. Casalini; A. Patkowski; T. Pakula; C. M. Roland

2003-01-01

14

Automatic segmentation of the coronary artery in MSCT volume data  

NASA Astrophysics Data System (ADS)

Extracting coronary artery is one of the vital steps in the analysis process based on the modality of computed tomography angiography (CTA), the aim of which is to recognize coronary artery from 3D volume data, and then provide evidences of analysis and quantitative measurement information for coronary artery computer aided detection. According to the structure features of coronary artery angiography scanned by multiple slices computed tomography (MSCT), an automatic segmentation algorithm is proposed. Firstly, detect and recognize the multiple seed points of the coronary artery in the scale space automatically from the 3D complex cardiac image datasets. Secondly, an improved layer region growing algorithm oriented to 3D tubular structure tissues is proposed to segment the coronary artery. Experiments show that the algorithm can extract coronary artery vessels effectively, which can improve the automation of coronary artery analysis, thus improve physicians' work efficiency.

Wang, Shengjun; Fu, Ling; Yue, Yong; Kang, Yan; Liu, Jiren

2009-10-01

15

Effect of volume changes on segmental relaxation in siloxane polymers.  

PubMed

From dielectric relaxation and equation-of-state measurements on polymethylphenylsiloxane and polymethyltolylsiloxane, the relative contributions of volume and thermal energy to the temperature dependence of the segmental relaxation times are quantified. In both polymers, volume exerts a substantial effect, being almost as significant as thermal energy. A possible consequence of this prominent role of volume in governing the segmental dynamics is the finding that the relaxation times, measured for a series of temperature at various (fixed) pressures, can be expressed as a single function of the volume normalized by the volume at the glass transition temperature. A similar result is found for the (isothermal) relaxation times measured at various pressures. PMID:14524793

Paluch, M; Casalini, R; Patkowski, A; Pakula, T; Roland, C M

2003-09-11

16

Effect of volume changes on segmental relaxation in siloxane polymers  

NASA Astrophysics Data System (ADS)

From dielectric relaxation and equation-of-state measurements on polymethylphenylsiloxane and polymethyltolylsiloxane, the relative contributions of volume and thermal energy to the temperature dependence of the segmental relaxation times are quantified. In both polymers, volume exerts a substantial effect, being almost as significant as thermal energy. A possible consequence of this prominent role of volume in governing the segmental dynamics is the finding that the relaxation times, measured for a series of temperature at various (fixed) pressures, can be expressed as a single function of the volume normalized by the volume at the glass transition temperature. A similar result is found for the (isothermal) relaxation times measured at various pressures.

Paluch, M.; Casalini, R.; Patkowski, A.; Pakula, T.; Roland, C. M.

2003-09-01

17

Interobserver variation in clinical target volume and organs at risk segmentation in post-parotidectomy radiotherapy: can segmentation protocols help?  

PubMed Central

Objective : A study of interobserver variation in the segmentation of the post-operative clinical target volume (CTV) and organs at risk (OARs) for parotid tumours was undertaken. The segmentation exercise was performed as a baseline, and repeated after 3 months using a segmentation protocol to assess whether CTV conformity improved. Methods : Four head and neck oncologists independently segmented CTVs and OARs (contralateral parotid, spinal cord and brain stem) on CT data sets of five patients post parotidectomy. For each CTV or OAR delineation, total volume was calculated. The conformity level (CL) between different clinicians' outlines was measured using a validated outline analysis tool. The data for CTVs were reaanalysed after using the cochlear sparing therapy and conventional radiation segmentation protocol. Results : Significant differences in CTV morphology were observed at baseline, yielding a mean CL of 30% (range 25–39%). The CL improved after using the segmentation protocol with a mean CL of 54% (range 50–65%). For OARs, the mean CL was 60% (range 53–68%) for the contralateral parotid gland, 23% (range 13–27%) for the brain stem and 25% (range 22–31%) for the spinal cord. Conclusions There was low conformity for CTVs and OARs between different clinicians. The CL for CTVs improved with use of a segmentation protocol, but the CLs remained lower than expected. This study supports the need for clear guidelines for segmentation of target and OARs to compare and interpret the results of head and neck cancer radiation studies.

Mukesh, M; Benson, R; Jena, R; Hoole, A; Roques, T; Scrase, C; Martin, C; Whitfield, G A; Gemmill, J; Jefferies, S

2012-01-01

18

Uterine fibroid segmentation and volume measurement on MRI  

NASA Astrophysics Data System (ADS)

Uterine leiomyomas are the most common pelvic tumors in females. The efficacy of medical treatment is gauged by shrinkage of the size of these tumors. In this paper, we present a method to robustly segment the fibroids on MRI and accurately measure the 3D volume. Our method is based on a combination of fast marching level set and Laplacian level set. With a seed point placed inside the fibroid region, a fast marching level set is first employed to obtain a rough segmentation, followed by a Laplacian level set to refine the segmentation. We devised a scheme to automatically determine the parameters for the level set function and the sigmoid function based on pixel statistics around the seed point. The segmentation is conducted on three concurrent views (axial, coronal and sagittal), and a combined volume measurement is computed to obtain a more reliable measurement. We carried out extensive tests on 13 patients, 25 MRI studies and 133 fibroids. The segmentation result was validated against manual segmentation defined by experts. The average segmentation sensitivity (true positive fraction) among all fibroids was 84.6%, and the average segmentation specificity (1-false positive fraction) was 84.3%.

Yao, Jianhua; Chen, David; Lu, Wenzhu; Premkumar, Ahalya

2006-03-01

19

Tumor volume measurement for nasopharyngeal carcinoma using knowledge-based fuzzy clustering MRI segmentation  

NASA Astrophysics Data System (ADS)

A knowledge-based fuzzy clustering (KBFC) MRI segmentation algorithm was proposed to obtain accurate tumor segmentation for tumor volume measurement of nasopharyngeal carcinoma (NPC). An initial segmentation was performed on T1 and contrast enhanced T1 MR images using a semi-supervised fuzzy c-means (SFCM) algorithm. Then, three types of anatomic and space knowledge--symmetry, connectivity and cluster center were used for image analysis which contributed the final tumor segmentation. After the segmentation, tumor volume was obtained by multi-planimetry method. Visual and quantitative validations were performed on phantom model and six data volumes of NPC patients, compared with ground truth (GT) and the results acquired using seeds growing (SG) for tumor segmentation. In visual format, KBFC showed better tumor segmentation image than SG. In quantitative segmentation quality estimation, on phantom model, the matching percent (MP) / correspondence ratio (CR) was 94.1-96.4% / 0.888-0.925 for KBFC and 94.1-96.0% / 0.884-0.918 for SG while on patient data volumes, it was 92.1+/- 2.6% / 0.884+/- 0.014 for KBFC and 87.4+/- 4.3% / 0.843+/- 0.041 for SG. In tumor volume measurement, on phantom model, measurement error was 4.2-5.0% for KBFC and 4.8-6.1% for SG while on patient data volumes, it was 6.6+/- 3.5% for KBFC and 8.8+/- 5.4% for SG. Based on these results, KBFC could provide high quality of MRI tumor segmentation for tumor volume measurement of NPC.

Zhou, Jiayin; Lim, Tuan K.; Chong, Vincent

2002-05-01

20

Normal brain volume measurements using multispectral MRI segmentation  

Microsoft Academic Search

The performance of a supervised k-nearest neighbor (kNN) classifier and a semisupervised fuzzy c-means (SFCM) clustering segmentation method are evaluated for reproducible measurement of the volumes of normal brain tissues and cerebrospinal fluid. The stability of the two segmentation methods is evaluated for (a) operator selection of training data, (b) reproducibility during repeat imaging sessions to determine any variations in

M. Vaidyanathan; L. P. Clarke; C. Heidtman; R. P. Velthuizen; L. O. Hall

1997-01-01

21

Segmental flow injection analysis, a hybrid technique of segmented continuous flow analysis and flow injection analysis  

Microsoft Academic Search

The use of a segmental flow injection analysis (SFIA) system, a hybrid of segmented continuous flow analysis (SCFA) and flow injection analysis (FIA) that integrates the essential favorable merits of FIA and SCFA, can significantly expand the application scope of flow analysis techniques by facilitating determinations with relatively slow reactions and\\/or requiring reaction at elevated temperatures. The higher dispersion with

Zheng-liang Zhi

1998-01-01

22

Video Segmentation Using Acoustic Analysis  

Microsoft Academic Search

Video segmentation is a key step for the long videos recorded from Television channels to be represented in the hierarchical structure. In this paper, a novel approach based on acoustic cues for automatic segmenting television stream into individual programs is proposed. This presented method is composed of the following steps: Several sets of repetitions in the audio track is detected

Shilin Zhang; Mei Gu

2010-01-01

23

Artificial Neural Network-Based System for PET Volume Segmentation  

PubMed Central

Tumour detection, classification, and quantification in positron emission tomography (PET) imaging at early stage of disease are important issues for clinical diagnosis, assessment of response to treatment, and radiotherapy planning. Many techniques have been proposed for segmenting medical imaging data; however, some of the approaches have poor performance, large inaccuracy, and require substantial computation time for analysing large medical volumes. Artificial intelligence (AI) approaches can provide improved accuracy and save decent amount of time. Artificial neural networks (ANNs), as one of the best AI techniques, have the capability to classify and quantify precisely lesions and model the clinical evaluation for a specific problem. This paper presents a novel application of ANNs in the wavelet domain for PET volume segmentation. ANN performance evaluation using different training algorithms in both spatial and wavelet domains with a different number of neurons in the hidden layer is also presented. The best number of neurons in the hidden layer is determined according to the experimental results, which is also stated Levenberg-Marquardt backpropagation training algorithm as the best training approach for the proposed application. The proposed intelligent system results are compared with those obtained using conventional techniques including thresholding and clustering based approaches. Experimental and Monte Carlo simulated PET phantom data sets and clinical PET volumes of nonsmall cell lung cancer patients were utilised to validate the proposed algorithm which has demonstrated promising results.

Sharif, Mhd Saeed; Abbod, Maysam; Amira, Abbes; Zaidi, Habib

2010-01-01

24

Video segmentation by audio analysis  

Microsoft Academic Search

In this paper, a novel approach based on acoustic cues for automatic segmenting television stream into individual programs is proposed. This presented method is composed of the following steps: Several sets of repetitions in the audio track is detected by using silence detection and robust audio hashing; The found repetitions are treated as advertisements if the range of their length

Shilin Zhang; Hui Wang

2010-01-01

25

The evaluation of a highly automated mixture model based technique for PET tumor volume segmentation  

NASA Astrophysics Data System (ADS)

PET-based tumor volume segmentation techniques are under investigation in recent years due to the increased utilization of FDG-PET imaging in radiation therapy. We have taken the approach of using a Gaussian mixture model (GMM) to model the image intensity distribution of a selected 3D region that completely covers the tumor, called the "analysis region". The modeling is performed with a predetermined number of Gaussian classes and results in a classification of every voxel into one of these classes. The classes are then grouped together to obtain the tumor volume. The only user interaction required is the selection of the "analysis region" and then the algorithm proceeds automatically to initialize the parameters of the different classes and finds the maximum likelihood estimate with expectation maximization. We used 13 clinical and 19 phantom cases to evaluate the precision and accuracy of the segmentation. Reproducibility was within 10% of the average tumor volume estimate and accuracy was +/-35% of the true tumor volume and better when compared to two other proposed techniques. The GMM segmentation is extremely user friendly with good precision and accuracy. It has shown great potential to be used in the clinical environment.

Aristophanous, Michalis; Pelizzari, Charles A.

2008-04-01

26

Partial volume segmentation in 3D of lesions and tissues in magnetic resonance images  

NASA Astrophysics Data System (ADS)

An important first step in diagnosis and treatment planning using tomographic imaging is differentiating and quantifying diseased as well as healthy tissue. One of the difficulties encountered in solving this problem to date has been distinguishing the partial volume constituents of each voxel in the image volume. Most proposed solutions to this problem involve analysis of planar images, in sequence, in two dimensions only. We have extended a model-based method of image segmentation which applies the technique of iterated conditional modes in three dimensions. A minimum of user intervention is required to train the algorithm. Partial volume estimates for each voxel in the image are obtained yielding fractional compositions of multiple tissue types for individual voxels. A multispectral approach is applied, where spatially registered data sets are available. The algorithm is simple and has been parallelized using a dataflow programming environment to reduce the computational burden. The algorithm has been used to segment dual echo MRI data sets of multiple sclerosis patients using lesions, gray matter, white matter, and cerebrospinal fluid as the partial volume constituents. The results of the application of the algorithm to these datasets is presented and compared to the manual lesion segmentation of the same data.

Johnston, Brian; Atkins, M. Stella; Booth, Kellogg S.

1994-05-01

27

Fuzzy hidden Markov chains segmentation for volume determination and quantitation in PET  

PubMed Central

Accurate volume of interest (VOI) estimation in PET is crucial in different oncology applications such as response to therapy evaluation and radiotherapy treatment planning. The objective of our study was to evaluate the performance of the proposed algorithm for automatic lesion volume delineation; namely the Fuzzy Hidden Markov Chains (FHMC), with that of current state of the art in clinical practice threshold based techniques. As the classical Hidden Markov Chain (HMC) algorithm, FHMC takes into account noise, voxel’s intensity and spatial correlation, in order to classify a voxel as background or functional VOI. However the novelty of the fuzzy model consists of the inclusion of an estimation of imprecision, which should subsequently lead to a better modelling of the “fuzzy” nature of the object on interest boundaries in emission tomography data. The performance of the algorithms has been assessed on both simulated and acquired datasets of the IEC phantom, covering a large range of spherical lesion sizes (from 10 to 37mm), contrast ratios (4:1 and 8:1) and image noise levels. Both lesion activity recovery and VOI determination tasks were assessed in reconstructed images using two different voxel sizes (8mm3 and 64mm3). In order to account for both the functional volume location and its size, the concept of % classification errors was introduced in the evaluation of volume segmentation using the simulated datasets. Results reveal that FHMC performs substantially better than the threshold based methodology for functional volume determination or activity concentration recovery considering a contrast ratio of 4:1 and lesion sizes of <28mm. Furthermore differences between classification and volume estimation errors evaluated were smaller for the segmented volumes provided by the FHMC algorithm. Finally, the performance of the automatic algorithms was less susceptible to image noise levels in comparison to the threshold based techniques. The analysis of both simulated and acquired datasets led to similar results and conclusions as far as the performance of segmentation algorithms under evaluation is concerned.

Hatt, Mathieu; Lamare, Frederic; Boussion, Nicolas; Roux, Christian; Turzo, Alexandre; Cheze-Lerest, Catherine; Jarritt, Peter; Carson, Kathryn; Salzenstein, Fabien; Collet, Christophe; Visvikis, Dimitris

2007-01-01

28

Semiautomatic regional segmentation to measure orbital fat volumes in thyroid-associated ophthalmopathy. A validation study.  

PubMed

This study was designed to validate a novel semi-automated segmentation method to measure regional intra-orbital fat tissue volume in Graves' ophthalmopathy. Twenty-four orbits from 12 patients with Graves' ophthalmopathy, 24 orbits from 12 controls, ten orbits from five MRI study simulations and two orbits from a digital model were used. Following manual region of interest definition of the orbital volumes performed by two operators with different levels of expertise, an automated procedure calculated intra-orbital fat tissue volumes (global and regional, with automated definition of four quadrants). In patients with Graves' disease, clinical activity score and degree of exophthalmos were measured and correlated with intra-orbital fat volumes. Operator performance was evaluated and statistical analysis of the measurements was performed. Accurate intra-orbital fat volume measurements were obtained with coefficients of variation below 5%. The mean operator difference in total fat volume measurements was 0.56%. Patients had significantly higher intra-orbital fat volumes than controls (p<0.001 using Student's t test). Fat volumes and clinical score were significantly correlated (p<0.001). The semi-automated method described here can provide accurate, reproducible intra-orbital fat measurements with low inter-operator variation and good correlation with clinical data. PMID:24007725

Comerci, M; Elefante, A; Strianese, D; Senese, R; Bonavolontà, P; Alfano, B; Bonavolontà, B; Brunetti, A

2013-08-27

29

Segmented ray casting for data parallel volume rendering  

Microsoft Academic Search

Interactive volume rendering is important for the timely analysis of three-dimensional data, but workstations take seconds to minutes to render data sets of a few megabytes. We have developed a parallel ray-casting technique. called Sepnenred Ray Cnsting, which can render a 128x128~128 data set at 2-3 frames per second on a 4K processor DECmpp 12OOO\\/Sx Model 100. Pixel values in

William M. Hsu

1993-01-01

30

Monocular road segmentation using slow feature analysis  

Microsoft Academic Search

In this paper a novel approach for road detection with a monocular camera is introduced. We propose a two step approach, combining a patch-based segmentation with additional boundary detection. We use Slow Feature Analysis (SFA) which leads to improved appearance descriptors for road and non-road parts on patch level. From the slow features a low order feature set is formed

Tobias Kuhnl; Franz Kummert; Jannik Fritsch

2011-01-01

31

Generic texture analysis applied to newspaper segmentation  

Microsoft Academic Search

This paper deals with the segmentation of grey-scale newspaper images into the distinct regions of text, picture and background. Feature vectors are obtained from the image by analysing localised textual characteristics and textual variation. Analysis is performed in a generic way making few contextual assumptions. The contrast, size, orientation and resolution of the image are accounted for by a combination

Paul Stefan Williams; Mike D. Alder

1996-01-01

32

Theoretical analysis of multispectral image segmentation criteria  

Microsoft Academic Search

Markov random field (MRF) image segmentation algorithms have been extensively studied, and have gained wide acceptance. However, almost all of the work on them has been experimental. This provides a good understanding of the performance of existing algorithms, but not a unified explanation of the significance of each component. To address this issue, we present a theoretical analysis of several

Ian B. Kerfoot; Yoram Bresler

1999-01-01

33

Brain tumor target volume determination for radiation therapy treatment planning through the use of automated MRI segmentation  

NASA Astrophysics Data System (ADS)

Radiation therapy seeks to effectively irradiate the tumor cells while minimizing the dose to adjacent normal cells. Prior research found that the low success rates for treating brain tumors would be improved with higher radiation doses to the tumor area. This is feasible only if the target volume can be precisely identified. However, the definition of tumor volume is still based on time-intensive, highly subjective manual outlining by radiation oncologists. In this study the effectiveness of two automated Magnetic Resonance Imaging (MRI) segmentation methods, k-Nearest Neighbors (kNN) and Knowledge-Guided (KG), in determining the Gross Tumor Volume (GTV) of brain tumors for use in radiation therapy was assessed. Three criteria were applied: accuracy of the contours; quality of the resulting treatment plan in terms of dose to the tumor; and a novel treatment plan evaluation technique based on post-treatment images. The kNN method was able to segment all cases while the KG method was limited to enhancing tumors and gliomas with clear enhancing edges. Various software applications were developed to create a closed smooth contour that encompassed the tumor pixels from the segmentations and to integrate these results into the treatment planning software. A novel, probabilistic measurement of accuracy was introduced to compare the agreement of the segmentation methods with the weighted average physician volume. Both computer methods under-segment the tumor volume when compared with the physicians but performed within the variability of manual contouring (28% +/- 12% for inter-operator variability). Computer segmentations were modified vertically to compensate for their under-segmentation. When comparing radiation treatment plans designed from physician-defined tumor volumes with treatment plans developed from the modified segmentation results, the reference target volume was irradiated within the same level of conformity. Analysis of the plans based on post-treatment MRI showed that the segmentation plans provided similar dose coverage to areas being treated by the original treatment plans. This research demonstrates that computer segmentations provide a feasible route to automatic target volume definition. Because of the lower variability and greater efficiency of the automated techniques, their use could lead to more precise plans and better prognosis for brain tumor patients.

Mazzara, Gloria Patrika

34

Segmentation of histological structures for fractal analysis  

NASA Astrophysics Data System (ADS)

Pathologists examine histology sections to make diagnostic and prognostic assessments regarding cancer based on deviations in cellular and/or glandular structures. However, these assessments are subjective and exhibit some degree of observer variability. Recent studies have shown that fractal dimension (a quantitative measure of structural complexity) has proven useful for characterizing structural deviations and exhibits great potential for automated cancer diagnosis and prognosis. Computing fractal dimension relies on accurate image segmentation to capture the architectural complexity of the histology specimen. For this purpose, previous studies have used techniques such as intensity histogram analysis and edge detection algorithms. However, care must be taken when segmenting pathologically relevant structures since improper edge detection can result in an inaccurate estimation of fractal dimension. In this study, we established a reliable method for segmenting edges from grayscale images. We used a Koch snowflake, an object of known fractal dimension, to investigate the accuracy of various edge detection algorithms and selected the most appropriate algorithm to extract the outline structures. Next, we created validation objects ranging in fractal dimension from 1.3 to 1.9 imitating the size, structural complexity, and spatial pixel intensity distribution of stained histology section images. We applied increasing intensity thresholds to the validation objects to extract the outline structures and observe the effects on the corresponding segmentation and fractal dimension. The intensity threshold yielding the maximum fractal dimension provided the most accurate fractal dimension and segmentation, indicating that this quantitative method could be used in an automated classification system for histology specimens.

Dixon, Vanessa; Kouznetsov, Alexei; Tambasco, Mauro

2009-02-01

35

Volume quantization of the mouse cerebellum by semiautomatic 3D segmentation of magnetic resonance images  

NASA Astrophysics Data System (ADS)

The aim of this work is the development of a non-invasive technique for efficient and accurate volume quantization of the cerebellum of mice. This enables an in-vivo study on the development of the cerebellum in order to define possible alterations in cerebellum volume of transgenic mice. We concentrate on a semi-automatic segmentation procedure to extract the cerebellum from 3D magnetic resonance data. The proposed technique uses a 3D variant of Vincent and Soille's immersion based watershed algorithm which is applied to the gradient magnitude of the MR data. The algorithm results in a partitioning of the data in volume primitives. The known drawback of the watershed algorithm, over-segmentation, is strongly reduced by a priori application of an adaptive anisotropic diffusion filter on the gradient magnitude data. In addition, over-segmentation is a posteriori contingently reduced by properly merging volume primitives, based on the minimum description length principle. The outcome of the preceding image processing step is presented to the user for manual segmentation. The first slice which contains the object of interest is quickly segmented by the user through selection of basic image regions. In the sequel, the subsequent slices are automatically segmented. The segmentation results are contingently manually corrected. The technique is tested on phantom objects, where segmentation errors less than 2% were observed. Three-dimensional reconstructions of the segmented data are shown for the mouse cerebellum and the mouse brains in toto.

Sijbers, Jan; van der Linden, Annemie; Scheunders, Paul; van Audekerke, Johan; van Dyck, Dirk; Raman, Erik

1996-04-01

36

Quantitative color analysis for capillaroscopy image segmentation.  

PubMed

This communication introduces a novel approach for quantitatively evaluating the role of color space decomposition in digital nailfold capillaroscopy analysis. It is clinically recognized that any alterations of the capillary pattern, at the periungual skin region, are directly related to dermatologic and rheumatic diseases. The proposed algorithm for the segmentation of digital capillaroscopy images is optimized with respect to the choice of the color space and the contrast variation. Since the color space is a critical factor for segmenting low-contrast images, an exhaustive comparison between different color channels is conducted and a novel color channel combination is presented. Results from images of 15 healthy subjects are compared with annotated data, i.e. selected images approved by clinicians. By comparison, a set of figures of merit, which highlights the algorithm capability to correctly segment capillaries, their shape and their number, is extracted. Experimental tests depict that the optimized procedure for capillaries segmentation, based on a novel color channel combination, presents values of average accuracy higher than 0.8, and extracts capillaries whose shape and granularity are acceptable. The obtained results are particularly encouraging for future developments on the classification of capillary patterns with respect to dermatologic and rheumatic diseases. PMID:22532162

Goffredo, Michela; Schmid, Maurizio; Conforto, Silvia; Amorosi, Beatrice; D'Alessio, Tommaso; Palma, Claudio

2012-04-25

37

A comparison of automated segmentation and manual tracing for quantifying hippocampal and amygdala volumes?  

PubMed Central

Large databases of high-resolution structural MR images are being assembled to quantitatively examine the relationships between brain anatomy, disease progression, treatment regimens, and genetic influences upon brain structure. Quantifying brain structures in such large databases cannot be practically accomplished by expert neuroanatomists using hand-tracing. Rather, this research will depend upon automated methods that reliably and accurately segment and quantify dozens of brain regions. At present, there is little guidance available to help clinical research groups in choosing such tools. Thus, our goal was to compare the performance of two popular and fully automated tools, FSL/FIRST and FreeSurfer, to expert hand tracing in the measurement of the hippocampus and amygdala. Volumes derived from each automated measurement were compared to hand tracing for percent volume overlap, percent volume difference, across-sample correlation, and 3-D group-level shape analysis. In addition, sample size estimates for conducting between-group studies were computed for a range of effect sizes. Compared to hand tracing, hippocampal measurements with FreeSurfer exhibited greater volume overlap, smaller volume difference, and higher correlation than FIRST, and sample size estimates with FreeSurfer were closer to hand tracing. Amygdala measurement with FreeSurfer was also more highly correlated to hand tracing than FIRST, but exhibited a greater volume difference than FIRST. Both techniques had comparable volume overlap and similar sample size estimates. Compared to hand tracing, a 3-D shape analysis of the hippocampus showed FreeSurfer was more accurate than FIRST, particularly in the head and tail. However, FIRST more accurately represented the amygdala shape than FreeSurfer, which inflated its anterior and posterior surfaces.

Morey, Rajendra A.; Petty, Christopher M.; Xu, Yuan; Hayes, Jasmeet Pannu; Wagner, H. Ryan; Lewis, Darrell V.; LaBar, Kevin S.; Styner, Martin; McCarthy, Gregory

2009-01-01

38

3D robust Chan-Vese model for industrial computed tomography volume data segmentation  

NASA Astrophysics Data System (ADS)

Industrial computed tomography (CT) has been widely applied in many areas of non-destructive testing (NDT) and non-destructive evaluation (NDE). In practice, CT volume data to be dealt with may be corrupted by noise. This paper addresses the segmentation of noisy industrial CT volume data. Motivated by the research on the Chan-Vese (CV) model, we present a region-based active contour model that draws upon intensity information in local regions with a controllable scale. In the presence of noise, a local energy is firstly defined according to the intensity difference within a local neighborhood. Then a global energy is defined to integrate local energy with respect to all image points. In a level set formulation, this energy is represented by a variational level set function, where a surface evolution equation is derived for energy minimization. Comparative analysis with the CV model indicates the comparable performance of the 3D robust Chan-Vese (RCV) model. The quantitative evaluation also shows the segmentation accuracy of 3D RCV. In addition, the efficiency of our approach is validated under several types of noise, such as Poisson noise, Gaussian noise, salt-and-pepper noise and speckle noise.

Liu, Linghui; Zeng, Li; Luan, Xiao

2013-11-01

39

AN AUTOMATIC FEATURE BASED MODEL FOR CELL SEGMENTATION FROM CONFOCAL MICROSCOPY VOLUMES  

PubMed Central

We present a model for the automated segmentation of cells from confocal microscopy volumes of biological samples. The segmentation task for these images is exceptionally challenging due to weak boundaries and varying intensity during the imaging process. To tackle this, a two step pruning process based on the Fast Marching Method is first applied to obtain an over-segmented image. This is followed by a merging step based on an effective feature representation. The algorithm is applied on two different datasets: one from the ascidian Ciona and the other from the plant Arabidopsis. The presented 3D segmentation algorithm shows promising results on these datasets.

Delibaltov, Diana; Ghosh, Pratim; Veeman, Michael; Smith, William; Manjunath, B.S.

2012-01-01

40

AN AUTOMATIC FEATURE BASED MODEL FOR CELL SEGMENTATION FROM CONFOCAL MICROSCOPY VOLUMES.  

PubMed

We present a model for the automated segmentation of cells from confocal microscopy volumes of biological samples. The segmentation task for these images is exceptionally challenging due to weak boundaries and varying intensity during the imaging process. To tackle this, a two step pruning process based on the Fast Marching Method is first applied to obtain an over-segmented image. This is followed by a merging step based on an effective feature representation. The algorithm is applied on two different datasets: one from the ascidian Ciona and the other from the plant Arabidopsis. The presented 3D segmentation algorithm shows promising results on these datasets. PMID:23154829

Delibaltov, Diana; Ghosh, Pratim; Veeman, Michael; Smith, William; Manjunath, B S

2011-01-01

41

Weight, Volume, and Center of Mass of Segments of the Human Body.  

National Technical Information Service (NTIS)

This study was designed to supplement existing knowledge of the weight, volume, and center of mass of segments of the human body and to permit their more accurate estimation on the living from anthropometric dimensions. Weight, volume, and center of mass ...

C. E. Clauser J. T. McConville J. W. Young

1969-01-01

42

Scintigraphic method for the assessment of intraluminal volume and motility of isolated intestinal segments. [Dogs  

SciTech Connect

The isolated in vivo intestinal segment is a popular experimental preparation for the investigation of intestinal function, but its value has been limited because no method has been available for measuring changes in intraluminal volume under experimental conditions. We report a scintigraphic technique for measuring intraluminal volume and assessing intestinal motility. Between 30 and 180 ml, the volume of a 75-cm segment of canine jejunum, perfused with Tc-99m-labeled tin colloid, was found to be proportional to the recorded count rate. This method has been used to monitor the effects of the hormone vasopressin on intestinal function.

Mitchell, A.; Macey, D.J.; Collin, J.

1983-07-01

43

Segmentation-free skeletonization of grayscale volumes for shape understanding  

Microsoft Academic Search

Medical imaging has produced a large number of volumetric images capturing biological structures in 3D. Computer-based understanding of these structures can often benefit from the knowledge of shape components, particularly rod-like and plate-like parts, in such volumes. Previously, skeletons have been a common tool for identifying these shape components in a solid object. However, obtaining skeletons of a grayscale volume

Sasakthi S. Abeysinghe; Matthew L. Baker; Wah Chiu; Tao Ju

2008-01-01

44

Magnetic resonance imaging based volume estimation of ovarian tumours: use of a segmentation and 3D reformation software.  

PubMed

The application of a new segmentation software, Anatomatic in the evaluation of volumetric measurements of ovarian tumours and the new Medimag three-dimensional (3D) software in the evaluation of 3D image representation of ovarian tumours with 1.5 T magnetic resonance imaging (MRI) is described. Our goal was to compare MRI based volumetry with operative findings at laparotomy for six consecutive patients with suspected ovarian tumours. Volumetric analysis and three dimensional image reconstructions of the tumours were obtained. At laparotomy, the tumour sizes were measured in situ, and the volumes were calculated. Using Anatomatic, reproducible tumour volumes were achieved with ease and within a reasonably fast time in patients with ovarian tumours without ascites. Medimag helped achieve realistic 3D representations of the tumours. For the four solitary tumours segmentation based volumetry and laparotomy findings agreed in three cases. In one patient with an oval shaped tumour, the segmented volume was double as compared to that estimated at laparotomy. Of the two patients with multiple tumours, both patients had significant ascites, and volumetry misinterpreted the fluid as tumour cyst fluid and markedly overestimated the tumour size. In conclusion, the MRI based segmentation volumetry and 3D image reconstructions are rapid, and reproducible methods of measuring ovarian tumours in patients without significant ascites. PMID:10988325

Dastidar, P; Mäenpää, J; Heinonen, T; Kuoppala, T; Van Meer, M; Punnonen, R; Laasonen, E

2000-11-01

45

Semi-Automatic Segmentation and Volume Determination of Brain Mass-Like Lesion  

Microsoft Academic Search

In this paper, a semi-automatic segmentation technique for brain mass-like lesions in magnetic resonance (MR) image sequences is proposed. With the graphical user interface of ImageJ, the user can interactively determine the lesion volume. The user needs to only provide the tumor contour on one MR slice using LiveWire, after which the system automatically segments and determines the gross lesion

Soontharee Koompairojn; Antoniya Petkova; Kien A. Hua; Pichest Metarugcheep

2008-01-01

46

Comprehensive evaluation of an image segmentation technique for measuring tumor volume from CT images  

NASA Astrophysics Data System (ADS)

Comprehensive quantitative evaluation of tumor segmentation technique on large scale clinical data sets is crucial for routine clinical use of CT based tumor volumetry for cancer diagnosis and treatment response evaluation. In this paper, we present a systematic validation study of a semi-automatic image segmentation technique for measuring tumor volume from CT images. The segmentation algorithm was tested using clinical data of 200 tumors in 107 patients with liver, lung, lymphoma and other types of cancer. The performance was evaluated using both accuracy and reproducibility. The accuracy was assessed using 7 commonly used metrics that can provide complementary information regarding the quality of the segmentation results. The reproducibility was measured by the variation of the volume measurements from 10 independent segmentations. The effect of disease type, lesion size and slice thickness of image data on the accuracy measures were also analyzed. Our results demonstrate that the tumor segmentation algorithm showed good correlation with ground truth for all four lesion types (r = 0.97, 0.99, 0.97, 0.98, p < 0.0001 for liver, lung, lymphoma and other respectively). The segmentation algorithm can produce relatively reproducible volume measurements on all lesion types (coefficient of variation in the range of 10-20%). Our results show that the algorithm is insensitive to lesion size (coefficient of determination close to 0) and slice thickness of image data(p > 0.90). The validation framework used in this study has the potential to facilitate the development of new tumor segmentation algorithms and assist large scale evaluation of segmentation techniques for other clinical applications.

Deng, Xiang; Huang, Haibin; Zhu, Lei; Du, Guangwei; Xu, Xiaodong; Sun, Yiyong; Xu, Chenyang; Jolly, Marie-Pierre; Chen, Jiuhong; Xiao, Jie; Merges, Reto; Suehling, Michael; Rinck, Daniel; Song, Lan; Jin, Zhengyu; Jiang, Zhaoxia; Wu, Bin; Wang, Xiaohong; Zhang, Shuai; Peng, Weijun

2008-04-01

47

Segmentation propagation for the automated quantification of ventricle volume from serial MRI  

NASA Astrophysics Data System (ADS)

Accurate ventricle volume estimates could potentially improve the understanding and diagnosis of communicating hydrocephalus. Postoperative communicating hydrocephalus has been recognized in patients with brain tumors where the changes in ventricle volume can be difficult to identify, particularly over short time intervals. Because of the complex alterations of brain morphology in these patients, the segmentation of brain ventricles is challenging. Our method evaluates ventricle size from serial brain MRI examinations; we (i) combined serial images to increase SNR, (ii) automatically segmented this image to generate a ventricle template using fast marching methods and geodesic active contours, and (iii) propagated the segmentation using deformable registration of the original MRI datasets. By applying this deformation to the ventricle template, serial volume estimates were obtained in a robust manner from routine clinical images (0.93 overlap) and their variation analyzed.

Linguraru, Marius George; Butman, John A.

2009-02-01

48

Three-dimensional analysis tool for segmenting and measuring the structure of telomeres in mammalian nuclei  

Microsoft Academic Search

Quantitative analysis in combination with fluorescence microscopy calls for innovative digital image measurement tools. We have developed a three-dimensional tool for segmenting and analyzing FISH stained telomeres in interphase nuclei. After deconvolution of the images, we segment the individual telomeres and measure a distribution parameter we call rhoT. This parameter describes if the telomeres are distributed in a sphere-like volume

Bart J. Vermolen; Ian T. Young; Alice Chuang; Landon Wark; Tony Chuang; Sabine Mai; Yuval Garini

2005-01-01

49

Comparison of EM-based and level set partial volume segmentations of MR brain images  

NASA Astrophysics Data System (ADS)

EM and level set algorithms are competing methods for segmenting MRI brain images. This paper presents a fair comparison of the two techniques using the Montreal Neurological Institute's software phantom. There are many flavors of level set algorithms for segmentation into multiple regions (multi-phase algorithms, multi-layer algorithms). The specific algorithm evaluated by us is a variant of the multi-layer level set algorithm. It uses a single level set function for segmenting the image into multiple classes and can be run to completion without restarting. The EM-based algorithm is standard. Both algorithms have the capacity to model a variable number of partial volume classes as well as image inhomogeneity (bias field). Our evaluation consists of systematically changing the number of partial volume classes, additive image noise, and regularization parameters. The results suggest that the performances of both algorithms are comparable across noise, number of partial volume classes, and regularization. The segmentation errors of both algorithms are around 5 - 10% for cerebrospinal fluid, gray and white matter. The level set algorithm appears to have a slight advantage for gray matter segmentation. This may be beneficial in studying certain brain diseases (Multiple Sclerosis or Alzheimer's disease) where small changes in gray matter volume are significant.

Tagare, Hemant D.; Chen, Yunmei; Fulbright, Robert K.

2008-04-01

50

Pulmonary airways tree segmentation from CT examinations using adaptive volume of interest  

NASA Astrophysics Data System (ADS)

Airways tree segmentation is an important step in quantitatively assessing the severity of and changes in several lung diseases such as chronic obstructive pulmonary disease (COPD), asthma, and cystic fibrosis. It can also be used in guiding bronchoscopy. The purpose of this study is to develop an automated scheme for segmenting the airways tree structure depicted on chest CT examinations. After lung volume segmentation, the scheme defines the first cylinder-like volume of interest (VOI) using a series of images depicting the trachea. The scheme then iteratively defines and adds subsequent VOIs using a region growing algorithm combined with adaptively determined thresholds in order to trace possible sections of airways located inside the combined VOI in question. The airway tree segmentation process is automatically terminated after the scheme assesses all defined VOIs in the iteratively assembled VOI list. In this preliminary study, ten CT examinations with 1.25mm section thickness and two different CT image reconstruction kernels ("bone" and "standard") were selected and used to test the proposed airways tree segmentation scheme. The experiment results showed that (1) adopting this approach affectively prevented the scheme from infiltrating into the parenchyma, (2) the proposed method reasonably accurately segmented the airways trees with lower false positive identification rate as compared with other previously reported schemes that are based on 2-D image segmentation and data analyses, and (3) the proposed adaptive, iterative threshold selection method for the region growing step in each identified VOI enables the scheme to segment the airways trees reliably to the 4th generation in this limited dataset with successful segmentation up to the 5th generation in a fraction of the airways tree branches.

Park, Sang Cheol; Kim, Won Pil; Zheng, Bin; Leader, Joseph K.; Pu, Jiantao; Tan, Jun; Gur, David

2009-02-01

51

Segmentation of cerebral gyri in the sectioned images by referring to volume model.  

PubMed

Authors had prepared the high-quality sectioned images of a cadaver head. For the delineation of each cerebral gyrus, three-dimensional model of the same brain was required. The purpose of this study was to develop the segmentation protocol of cerebral gyri by referring to the three-dimensional model on the personal computer. From the 114 sectioned images (intervals, 1 mm), a cerebral hemisphere was outlined. On MRIcro software, sectioned images including only the cerebral hemisphere were volume reconstructed. The volume model was rotated to capture the lateral, medial, superior, and inferior views of the cerebral hemisphere. On these four views, areas of 33 cerebral gyri were painted with colors. Derived from the painted views, the cerebral gyri in sectioned images were identified and outlined on the Photoshop to prepare segmented images. The segmented images were used for production of volume and surface models of the selected gyri. The segmentation method developed in this research is expected to be applied to other types of images, such as MRIs. Our results of the sectioned and segmented images of the cadaver brain, acquired in the present study, are hopefully utilized for medical learning tools of neuroanatomy. PMID:21165283

Park, Jin Seo; Chung, Min Suk; Chi, Je-Geun; Park, Hyo Seok; Shin, Dong Sun

2010-11-24

52

Video segmentation based on acoustic analysis  

Microsoft Academic Search

Video segmentation is a key step for the long videos recorded from Television channels to be represented in the hierarchical structure. In this paper, a novel approach based on acoustic cues for automatic segmenting television stream into individual programs is proposed. This presented method is composed of the following steps: Several sets of repetitions in the audio track is detected

Shilin Zhang; Hui Wang

2010-01-01

53

Applying Acoustic Analysis to Video Segmentation  

Microsoft Academic Search

Video segmentation is a key step for the long videos recorded from Television channels to be represented in the hierarchical structure. In this paper, a novel approach based on acoustic cues for automatic segmenting television stream into individual programs is proposed. This presented method is composed of the following steps: Several sets of repetitions in the audio track is detected

Shilin Zhang; Mei Gu

2010-01-01

54

Segmentation of 3D object in volume dataset using active deformable model  

Microsoft Academic Search

The level set approach can be used as powerful tool for volume segmentation of a region-of-interest (ROI), to achieve an accurate estimation of tumor or soft tissue in medical images. A major challenge of such algorithms is required to set the equation parameters, especially in the speed function. In this paper, we introduce a geometric active surface scheme that uses

Jonghyun Park; Wanhyun Cho; Soon-Young Park; Sun-Worl Kim; Soo-Hyung Kim; Gukdong Ahn; Myung-Eun Lee; Gueesang Lee

2010-01-01

55

Precise segmentation of multiple organs in CT volumes using learning-based approach and information theory.  

PubMed

In this paper, we present a novel method by incorporating information theory into the learning-based approach for automatic and accurate pelvic organ segmentation (including the prostate, bladder and rectum). We target 3D CT volumes that are generated using different scanning protocols (e.g., contrast and non-contrast, with and without implant in the prostate, various resolution and position), and the volumes come from largely diverse sources (e.g., diseased in different organs). Three key ingredients are combined to solve this challenging segmentation problem. First, marginal space learning (MSL) is applied to efficiently and effectively localize the multiple organs in the largely diverse CT volumes. Second, learning techniques, steerable features, are applied for robust boundary detection. This enables handling of highly heterogeneous texture pattern. Third, a novel information theoretic scheme is incorporated into the boundary inference process. The incorporation of the Jensen-Shannon divergence further drives the mesh to the best fit of the image, thus improves the segmentation performance. The proposed approach is tested on a challenging dataset containing 188 volumes from diverse sources. Our approach not only produces excellent segmentation accuracy, but also runs about eighty times faster than previous state-of-the-art solutions. The proposed method can be applied to CT images to provide visual guidance to physicians during the computer-aided diagnosis, treatment planning and image-guided radiotherapy to treat cancers in pelvic region. PMID:23286081

Lu, Chao; Zheng, Yefeng; Birkbeck, Neil; Zhang, Jingdan; Kohlberger, Timo; Tietjen, Christian; Boettger, Thomas; Duncan, James S; Zhou, S Kevin

2012-01-01

56

Continuation of Static Tests of Segments of Tunnel Linings. Volume II Data.  

National Technical Information Service (NTIS)

Volume II presents the complete set of laboratory data obtained from a continuation series of 19 quasi-static tests of segments of cylindrical tunnel linings. Test specimens included scale models of a composite-integral structure and a steel structure wit...

H. C. Davis K. B. Morrill J. L. Merritt

1979-01-01

57

Comparative assessment of statistical brain MR image segmentation algorithms and their impact on partial volume correction in PET.  

PubMed

Magnetic resonance imaging (MRI)-guided partial volume effect correction (PVC) in brain positron emission tomography (PET) is now a well-established approach to compensate the large bias in the estimate of regional radioactivity concentration, especially for small structures. The accuracy of the algorithms developed so far is, however, largely dependent on the performance of segmentation methods partitioning MRI brain data into its main classes, namely gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). A comparative evaluation of three brain MRI segmentation algorithms using simulated and clinical brain MR data was performed, and subsequently their impact on PVC in 18F-FDG and 18F-DOPA brain PET imaging was assessed. Two algorithms, the first is bundled in the Statistical Parametric Mapping (SPM2) package while the other is the Expectation Maximization Segmentation (EMS) algorithm, incorporate a priori probability images derived from MR images of a large number of subjects. The third, here referred to as the HBSA algorithm, is a histogram-based segmentation algorithm incorporating an Expectation Maximization approach to model a four-Gaussian mixture for both global and local histograms. Simulated under different combinations of noise and intensity non-uniformity, MR brain phantoms with known true volumes for the different brain classes were generated. The algorithms' performance was checked by calculating the kappa index assessing similarities with the "ground truth" as well as multiclass type I and type II errors including misclassification rates. The impact of image segmentation algorithms on PVC was then quantified using clinical data. The segmented tissues of patients' brain MRI were given as input to the region of interest (RoI)-based geometric transfer matrix (GTM) PVC algorithm, and quantitative comparisons were made. The results of digital MRI phantom studies suggest that the use of HBSA produces the best performance for WM classification. For GM classification, it is suggested to use the EMS. Segmentation performed on clinical MRI data show quite substantial differences, especially when lesions are present. For the particular case of PVC, SPM2 and EMS algorithms show very similar results and may be used interchangeably. The use of HBSA is not recommended for PVC. The partial volume corrected activities in some regions of the brain show quite large relative differences when performing paired analysis on 2 algorithms, implying a careful choice of the segmentation algorithm for GTM-based PVC. PMID:16828315

Zaidi, Habib; Ruest, Torsten; Schoenahl, Frederic; Montandon, Marie-Louise

2006-07-07

58

Topology Adaptive Deformable Surfaces for Medical Image Volume Segmentation  

Microsoft Academic Search

Deformable models, which include deformable con- tours (the popular snakes) and deformable surfaces, are a power- ful model-based medical image analysis technique. We develop a new class of deformable models by formulating deformable sur- faces in terms of an affine cell image decomposition (ACID). Our approach significantly extends standard deformable surfaces, while retaining their interactivity and other desirable properties. In

Tim Mcinerney; Demetri Terzopoulos

1999-01-01

59

Analysis of Prestressed Concrete Wall Segments.  

National Technical Information Service (NTIS)

An iterative numerical technique for analysing the biaxial response of reinforced and prestressed concrete wall segments subject to combinations of prestressing, creep, temperature and live loads is presented. Two concrete constitutive relations are avail...

B. D. P. Koziak D. W. Murray

1979-01-01

60

Simulation and Evaluation of Phonetic Speech Recognition Techniques. Volume II. Segmentation of Continuous Speech into Phonemes.  

National Technical Information Service (NTIS)

The objective of the program is the analysis of design parameters required for the simulation and evaluation of phonetic speech recognition methods. An approach to the segmentation of continuous speech into phonemes is described, and the results of segmen...

K. W. Otten

1964-01-01

61

Design and Analysis of an Efficient Evolutionary Image Segmentation Algorithm  

Microsoft Academic Search

Evolutionary image segmentation algorithms have a number of advantages such as continuous contour, non-oversegmentation, and non-thresholds. However, most of the evolutionary image segmentation algorithms suffer from long computation time because the number of encoding parameters is large. In this paper, design and analysis of an efficient evolutionary image segmentation algorithm EISA are proposed. EISA uses a K-means algorithm to split

Shinn-ying Ho; Kual-zheng Lee

2003-01-01

62

Cell nuclei segmentation for histopathological image analysis  

NASA Astrophysics Data System (ADS)

In this paper, we propose a supervised method for segmenting cell nuclei from background and extra-cellular regions in pathological images. To this end, we segment the cell regions from the other areas by classifying the image pixels into either cell or extra-cellular category. Instead of using pixel color intensities, the color-texture extracted at the local neighborhood of each pixel is utilized as the input to our classification algorithm. The color-texture at each pixel is extracted by local Fourier transform (LFT) from a new color space, the most discriminant color space (MDC). The MDC color space is optimized to be a linear combination of the original RGB color space so that the extracted LFT texture features in the MDC color space can achieve the most discrimination in terms of classification (segmentation) performance. To speed up the texture feature extraction process, we develop an efficient LFT extraction algorithm based on image shifting and image integral. For evaluation, our method is compared with the state-of-the-art segmentation algorithms (Graph-cut, Mean-shift, etc.). Empirical results show that our segmentation method achieves better performance than these popular methods.

Kong, Hui; Belkacem-Boussaid, Kamel; Gurcan, Metin

2011-03-01

63

Learning Taxonomy for Text Segmentation by Formal Concept Analysis  

Microsoft Academic Search

In this paper the problems of deriving a taxonomy from a text and\\u000aconcept-oriented text segmentation are approached. Formal Concept Analysis\\u000a(FCA) method is applied to solve both of these linguistic problems. The\\u000aproposed segmentation method offers a conceptual view for text segmentation,\\u000ausing a context-driven clustering of sentences. The Concept-oriented Clustering\\u000aSegmentation algorithm (COCS) is based on k-means linear

Mihaiela Lupea; Doina Tatar; Zsuzsana Marian

2010-01-01

64

Topic-based document segmentation with probabilistic latent semantic analysis  

Microsoft Academic Search

This paper presents a new method for topic-based document segmentation, i.e., the identification of boundaries between parts of a document that bear on different topics. The method combines the use of the Probabilistic Latent Semantic Analysis (PLSA) model with the method of selecting segmentation points based on the similarity values between pairs of adjacent blocks. The use of PLSA allows

Thorsten Brants; Francine Chen; Ioannis Tsochantaridis

2002-01-01

65

Robust semi-automatic segmentation of single- and multichannel MRI volumes through adaptable class-specific representation  

NASA Astrophysics Data System (ADS)

Segmentation of MRI volumes is complicated by noise, inhomogeneity and partial volume artefacts. Fully or semi-automatic methods often require time consuming or unintuitive initialization. Adaptable Class-Specific Representation (ACSR) is a semi-automatic segmentation framework implemented by the Path Growing Algorithm (PGA), which reduces artefacts near segment boundaries. The user visually defines the desired segment classes through the selection of class templates and the following segmentation process is fully automatic. Good results have previously been achieved with color cryo section segmentation and ACSR has been developed further for the MRI modality. In this paper we present two optimizations for robust ACSR segmentation of MRI volumes. Automatic template creation based on an initial segmentation step using Learning Vector Quantization is applied for higher robustness to noise. Inhomogeneity correction is added as a pre-processing step, comparing the EQ and N3 algorithms. Results based on simulated T1-weighed and multispectral (T1 and T2) MRI data from the BrainWeb database and real data from the Internet Brain Segmentation Repository are presented. We show that ACSR segmentation compares favorably to previously published results on the same volumes and discuss the pros and cons of using quantitative ground truth evaluation compared to qualitative visual assessment.

Nielsen, Casper F.; Passmore, Peter J.

2002-05-01

66

Multi-stage learning for robust lung segmentation in challenging CT volumes.  

PubMed

Simple algorithms for segmenting healthy lung parenchyma in CT are unable to deal with high density tissue common in pulmonary diseases. To overcome this problem, we propose a multi-stage learning-based approach that combines anatomical information to predict an initialization of a statistical shape model of the lungs. The initialization first detects the carina of the trachea, and uses this to detect a set of automatically selected stable landmarks on regions near the lung (e.g., ribs, spine). These landmarks are used to align the shape model, which is then refined through boundary detection to obtain fine-grained segmentation. Robustness is obtained through hierarchical use of discriminative classifiers that are trained on a range of manually annotated data of diseased and healthy lungs. We demonstrate fast detection (35s per volume on average) and segmentation of 2 mm accuracy on challenging data. PMID:22003757

Sofka, Michal; Wetzl, Jens; Birkbeck, Neil; Zhang, Jingdan; Kohlberger, Timo; Kaftan, Jens; Declerck, Jérôme; Zhou, S Kevin

2011-01-01

67

Web ontology segmentation: analysis, classification and use  

Microsoft Academic Search

Ontologies are at the heart of the semantic web. They define the concepts and relationships that make global interoperability possi- ble. However, as these ontologies grow in size they become more and more difficult to create, use, understand, maintain, transform and classify. We present and evaluate several algorithms for extract- ing relevant segments out of large description logic ontologies for

Julian Seidenberg; Alan L. Rector

2006-01-01

68

Dynamic Seismic Analysis of Long Segmented Lifelines.  

National Technical Information Service (NTIS)

The difference in ground motion along a lifeline, the incoherent motion, is an essential component of the input. A long, straight, segmented pipe, with each link attached to the ground via a spring and dashpot is subjected to incoherent ground motion caus...

I. Nelson P. Weidlinger

1978-01-01

69

Microarray Analysis of Focal Segmental Glomerulosclerosis  

Microsoft Academic Search

Background: Focal segmental glomerulosclerosis (FSGS) is a leading cause of chronic renal failure in children. Recent studies have begun to define the molecular pathogenesis of this heterogeneous condition. Here we use oligonucleotide microarrays to obtain a global gene expression profile of kidney biopsy specimens from patients with FSGS in order to better understand the pathogenesis of this disease. Methods: We

Kristopher Schwab; David P. Witte; Bruce J. Aronow; Prasad Devarajan; S. Steven Potter; Larry T. Patterson

2004-01-01

70

Global Positioning System Control/User Segments. Volume III. User Segment Description, Performance, Error Budgets, and RF Link Budgets.  

National Technical Information Service (NTIS)

The User Segment includes navigation hardware necessary to determine position or navigation data of the user in earth-centered coordinates. As such, it accomplishes receiver and computational functions. The User Segment measures pseudorange and range rate...

1974-01-01

71

Coronary Endothelium-Dependent Vasoreactivity and Atheroma Volume in Subjects With Stable, Minimal Angiographic Disease Versus Non-ST-Segment-Elevation Myocardial Infarction: An Intravascular Ultrasound Study.  

PubMed

Background- Epicardial plaque burden and endothelial function are recognized predictors of coronary events. We aimed to investigate mechanistic relationships between atheroma volume and endothelial function in patients with non-ST-segment-elevation myocardial infarction (NSTEMI) using intravascular ultrasound. Methods and Results- In coronary vessels of patients with near-normal or minimal angiographic disease (n=23) and NSTEMI (n=24), intravascular ultrasound-derived measures (percent atheroma volume), arterial remodeling index, and segmental lumen volumes were performed in contiguous 5-mm epicardial segments. Repeat intravascular ultrasound imaging was performed after consecutive 5-minute intracoronary infusions (vehicle solution, 0.30 ?g/min and 0.60 ?g/min intracoronary salbutamol) to measure changes in segmental lumen volume (endothelium-dependent function). Male sex, diabetes mellitus, smoking, higher triglycerides, and lower high-density lipoprotein cholesterol were more prevalent in the NSTEMI group. Patients with NSTEMI demonstrated greater segmental percent atheroma volume (40.4±12 versus 27.5±14%, P<0.001), remodeling index (1.2 [1.0-1.5] versus 1.0 [0.9-1.0], P<0.001), and displayed less endothelium-dependent vasomotion (% change segmental lumen volume: 2.1±0.89 versus 5.1±0.89%, P=0.02) compared to patients with minimal angiographic disease. No significant difference in endothelial function between both groups was observed when controlling for plaque burden. Multivariate analysis for change in segmental lumen volume identified percent atheroma volume (?=-0.18, P=0.0004), high-sensitivity C-reactive protein >2 mg/L (?=-3.1, P=0.03), diabetes mellitus (?=-6.9, P<0.0001), low-density lipoprotein cholesterol levels (?=-0.04, P=0.01), and smoking (?=-3.2, P=0.01) as independent associates. Conclusions- Although coronary endothelial vasoreactivity is blunted in the setting of NSTEMI, this is a reflection of the greater volume of atherosclerosis and cardiovascular risk factors. Thus, the relationship between coronary endothelium-dependent vasomotor reactivity and atheroma volume remains constant irrespective of the nature of the clinical presentation. PMID:23811749

Puri, Rishi; Nicholls, Stephen J; Nissen, Steven E; Brennan, Danielle M; Andrews, Jordan; Liew, Gary Y; Nelson, Adam J; Carbone, Angelo; Copus, Barbara; Tuzcu, E Murat; Beltrame, John F; Worthley, Stephen G; Worthley, Matthew I

2013-06-27

72

Advanced Distributed Simulation Technology Advanced Rotary Wing Aircraft. System/Segment Specification. Volume 3. Visual System Module.  

National Technical Information Service (NTIS)

The ADST ARWA System/Segment Specification establishes the functional requirements for the Advanced Rotary Wing Aircraft (ARWA) Simulator System (SS). Volume III describes the requirements for the Visual System Module (VSM). The VSM component provides fun...

R. Branson R. Anschuetz

1994-01-01

73

Four-chamber heart modeling and automatic segmentation for 3D cardiac CT volumes  

NASA Astrophysics Data System (ADS)

Multi-chamber heart segmentation is a prerequisite for quantification of the cardiac function. In this paper, we propose an automatic heart chamber segmentation system. There are two closely related tasks to develop such a system: heart modeling and automatic model fitting to an unseen volume. The heart is a complicated non-rigid organ with four chambers and several major vessel trunks attached. A flexible and accurate model is necessary to capture the heart chamber shape at an appropriate level of details. In our four-chamber surface mesh model, the following two factors are considered and traded-off: 1) accuracy in anatomy and 2) easiness for both annotation and automatic detection. Important landmarks such as valves and cusp points on the interventricular septum are explicitly represented in our model. These landmarks can be detected reliably to guide the automatic model fitting process. We also propose two mechanisms, the rotation-axis based and parallel-slice based resampling methods, to establish mesh point correspondence, which is necessary to build a statistical shape model to enforce priori shape constraints in the model fitting procedure. Using this model, we develop an efficient and robust approach for automatic heart chamber segmentation in 3D computed tomography (CT) volumes. Our approach is based on recent advances in learning discriminative object models and we exploit a large database of annotated CT volumes. We formulate the segmentation as a two step learning problem: anatomical structure localization and boundary delineation. A novel algorithm, Marginal Space Learning (MSL), is introduced to solve the 9-dimensional similarity transformation search problem for localizing the heart chambers. After determining the pose of the heart chambers, we estimate the 3D shape through learning-based boundary delineation. Extensive experiments demonstrate the efficiency and robustness of the proposed approach, comparing favorably to the state-of-the-art. This is the first study reporting stable results on a large cardiac CT dataset with 323 volumes. In addition, we achieve a speed of less than eight seconds for automatic segmentation of all four chambers.

Zheng, Yefeng; Georgescu, Bogdan; Barbu, Adrian; Scheuering, Michael; Comaniciu, Dorin

2008-04-01

74

AMASS: Algorithm for MSI Analysis by Semi-supervised Segmentation  

PubMed Central

Mass Spectrometric Imaging (MSI) is a molecular imaging technique that allows the generation of 2D ion density maps for a large complement of the active molecules present in cells and sectioned tissues. Automatic segmentation of such maps according to patterns of co-expression of individual molecules can be used for discovery of novel molecular signatures (molecules that are specifically expressed in particular spatial regions). However, current segmentation techniques are biased towards the discovery of higher abundance molecules and large segments; they allow limited opportunity for user interaction and validation is usually performed by similarity to known anatomical features. We describe here a novel method, AMASS (Algorithm for MSI Analysis by Semi-supervised Segmentation). AMASS relies on the discriminating power of a molecular signal instead of its intensity as a key feature, uses an internal consistency measure for validation, and allows significant user interaction and supervision as options. An automated segmentation of entire leech embryo data images resulted in segmentation domains congruent with many known organs, including heart, CNS ganglia, nephridia, nephridiopores, and lateral and ventral regions, each with a distinct molecular signature. Likewise, segmentation of a rat brain MSI slice data set yielded known brain features, and provided interesting examples of co-expression between distinct brain regions. AMASS represents a new approach for the discovery of peptide masses with distinct spatial features of expression.

Bruand, Jocelyne; Alexandrov, Theodore; Sistla, Srinivas; Wisztorski, Maxence; Meriaux, Celine; Becker, Michael; Salzet, Michel; Fournier, Isabelle; Macagno, Eduardo; Bafna, Vineet

2011-01-01

75

Quantification of left ventricular volume and global function using a fast automated segmentation tool: validation in a clinical setting.  

PubMed

Real-time 3D echocardiography (RT3DE) has already been shown to be an accurate tool for left ventricular (LV) volume assessment. However, LV border detection in RT3DE remains a time-consuming task jeopardizing the application of this modality in routine practice. We have recently developed a 3D automated segmentation framework (BEAS) able to capture the LV morphology in real-time. The goal of this study was to assess the accuracy of this approach in extracting volumetric parameters in a clinical setting. 24 RT3DE exams were acquired in a group of healthy volunteers (# = 5) and diseased patients (# = 19), with LV volume/function within a range typically measured in a clinical setting. End-diastolic and end-systolic volumes (EDV, ESV) were manually contoured by 3 expert sonographers from which the stroke volume and ejection fraction (SV, EF) were calculated. The values extracted with BEAS were compared to the average of the 3 experts measurements using correlation and Bland-Altman statistics. Linear regression analysis showed a strong correlation between the automated algorithm and the reference values (R = 0.963, 0.947, 0.944 and 0.853 for EDV, ESV, SV and EF respectively). Bland-Altman analysis revealed a bias (limits of agreement) of 2.59 (-25.39, 30.57) ml, -2.11 (-24.91, 20.69) ml, 4.70 (12.93, 22.34) ml and 3.45 (-8.96, 15.87) %, for EDV, ESV, SV and EF respectively. Total analysis time using BEAS was 30.7 ± 7.5 s. BEAS allows for a fast and accurate quantification of 3D cardiac volumes and global function with minimal user input. It may therefore contribute to the integration of 3D echocardiography in routine clinical practice. PMID:22850929

Barbosa, Daniel; Heyde, Brecht; Dietenbeck, Thomas; Houle, Helene; Friboulet, Denis; Bernard, Olivier; D'hooge, Jan

2012-08-01

76

A SEGMENTATION ANALYSIS OF U.S. GROCERY STORE SHOPPERS  

Microsoft Academic Search

Cluster analysis was used to conduct a segmentation analysis of U.S. supermarket shoppers. This study is based on the responses of a sample of 1,000 shoppers concerning the importance of 21 store characteristics in selecting their primary grocery store for the Food Marketing Institute's 2000 consumer trends survey. Stores must satisfy the attributes important to all consumers in order to

Sandeep Mangaraj; Benjamin Senauer

2001-01-01

77

A Likelihood and Local Constraint Level Set Model for Liver Tumor Segmentation from CT Volumes.  

PubMed

In computed tomography of liver tumors there is often heterogeneous density, weak boundaries, and the liver tumors are surrounded by other abdominal structures with similar densities. These pose limitations to accurate the hepatic tumor segmentation. We propose a level set model incorporating likelihood energy with the edge energy. The minimization of the likelihood energy approximates the density distribution of the target and the multimodal density distribution of the background that can have multiple regions. In the edge energy formulation, our edge detector preserves the ramp associated with the edges for weak boundaries. We compared our approach to the Chan-Vese and the geodesic level set models and the manual segmentation performed by clinical experts. The Chan-Vese model was not successful in segmenting hepatic tumors and our model outperformed the geodesic level set model. Our results on 18 clinical datasets showed that our algorithm had a Jaccard distance error of 14.4 ± 5.3%, relative volume difference of -8.1 ± 2.1%, average surface distance of 2.4 ± 0.8 mm, RMS surface distance of 2.9 ± 0.7 mm, and the maximum surface distance of 7.2 ± 3.1 mm. PMID:23771304

Li, Changyang; Wang, Xiuying; Eberl, Stefan; Fulham, Michael; Yin, Yong; Chen, Jinhu; Feng, David Dagan

2013-06-10

78

Machine learning based vesselness measurement for coronary artery segmentation in cardiac CT volumes  

NASA Astrophysics Data System (ADS)

Automatic coronary centerline extraction and lumen segmentation facilitate the diagnosis of coronary artery disease (CAD), which is a leading cause of death in developed countries. Various coronary centerline extraction methods have been proposed and most of them are based on shortest path computation given one or two end points on the artery. The major variation of the shortest path based approaches is in the different vesselness measurements used for the path cost. An empirically designed measurement (e.g., the widely used Hessian vesselness) is by no means optimal in the use of image context information. In this paper, a machine learning based vesselness is proposed by exploiting the rich domain specific knowledge embedded in an expert-annotated dataset. For each voxel, we extract a set of geometric and image features. The probabilistic boosting tree (PBT) is then used to train a classifier, which assigns a high score to voxels inside the artery and a low score to those outside. The detection score can be treated as a vesselness measurement in the computation of the shortest path. Since the detection score measures the probability of a voxel to be inside the vessel lumen, it can also be used for the coronary lumen segmentation. To speed up the computation, we perform classification only for voxels around the heart surface, which is achieved by automatically segmenting the whole heart from the 3D volume in a preprocessing step. An efficient voxel-wise classification strategy is used to further improve the speed. Experiments demonstrate that the proposed learning based vesselness outperforms the conventional Hessian vesselness in both speed and accuracy. On average, it only takes approximately 2.3 seconds to process a large volume with a typical size of 512x512x200 voxels.

Zheng, Yefeng; Loziczonek, Maciej; Georgescu, Bogdan; Zhou, S. Kevin; Vega-Higuera, Fernando; Comaniciu, Dorin

2011-03-01

79

Four-chamber heart modeling and automatic segmentation for 3-D cardiac CT volumes using marginal space learning and steerable features.  

PubMed

We propose an automatic four-chamber heart segmentation system for the quantitative functional analysis of the heart from cardiac computed tomography (CT) volumes. Two topics are discussed: heart modeling and automatic model fitting to an unseen volume. Heart modeling is a nontrivial task since the heart is a complex nonrigid organ. The model must be anatomically accurate, allow manual editing, and provide sufficient information to guide automatic detection and segmentation. Unlike previous work, we explicitly represent important landmarks (such as the valves and the ventricular septum cusps) among the control points of the model. The control points can be detected reliably to guide the automatic model fitting process. Using this model, we develop an efficient and robust approach for automatic heart chamber segmentation in 3-D CT volumes. We formulate the segmentation as a two-step learning problem: anatomical structure localization and boundary delineation. In both steps, we exploit the recent advances in learning discriminative models. A novel algorithm, marginal space learning (MSL), is introduced to solve the 9-D similarity transformation search problem for localizing the heart chambers. After determining the pose of the heart chambers, we estimate the 3-D shape through learning-based boundary delineation. The proposed method has been extensively tested on the largest dataset (with 323 volumes from 137 patients) ever reported in the literature. To the best of our knowledge, our system is the fastest with a speed of 4.0 s per volume (on a dual-core 3.2-GHz processor) for the automatic segmentation of all four chambers. PMID:18955181

Zheng, Yefeng; Barbu, Adrian; Georgescu, Bogdan; Scheuering, Michael; Comaniciu, Dorin

2008-11-01

80

4-D segmentation and normalization of 3He MR images for intrasubject assessment of ventilated lung volumes  

NASA Astrophysics Data System (ADS)

Although 3He MRI permits compelling visualization of the pulmonary air spaces, quantitation of absolute ventilation is difficult due to confounds such as field inhomogeneity and relative intensity differences between image acquisition; the latter complicating longitudinal investigations of ventilation variation with respiratory alterations. To address these potential difficulties, we present a 4-D segmentation and normalization approach for intra-subject quantitative analysis of lung hyperpolarized 3He MRI. After normalization, which combines bias correction and relative intensity scaling between longitudinal data, partitioning of the lung volume time series is performed by iterating between modeling of the combined intensity histogram as a Gaussian mixture model and modulating the spatial heterogeneity tissue class assignments through Markov random field modeling. Evaluation of the algorithm was retrospectively applied to a cohort of 10 asthmatics between 19-25 years old in which spirometry and 3He MR ventilation images were acquired both before and after respiratory exacerbation by a bronchoconstricting agent (methacholine). Acquisition was repeated under the same conditions from 7 to 467 days (mean +/- standard deviation: 185 +/- 37.2) later. Several techniques were evaluated for matching intensities between the pre and post-methacholine images with the 95th percentile value histogram matching demonstrating superior correlations with spirometry measures. Subsequent analysis evaluated segmentation parameters for assessing ventilation change in this cohort. Current findings also support previous research that areas of poor ventilation in response to bronchoconstriction are relatively consistent over time.

Contrella, Benjamin; Tustison, Nicholas J.; Altes, Talissa A.; Avants, Brian B.; Mugler, John P., III; de Lange, Eduard E.

2012-02-01

81

Lung image segmentation and registration for quantitative image analysis  

Microsoft Academic Search

Functional images obtained PET and\\/or SPECT become more useful when those images are provided with detail anatomical information obtained by X ray CT or MRI. A series of image processing including image registration and segmentation is presented for quantitative analysis of functional images. A clinical application described in the paper is to evaluate the effect of radiation therapy for lung

Hideaki Haneishi; Hidenori Ue; Noriaki Takita; Hinako Toyama; Tadaaki Miyamoto; Naoyohi Yamamoto; Yutaka Mori

2001-01-01

82

Bscan image segmentation by thresholding using cooccurrence matrix analysis  

Microsoft Academic Search

In this paper we present innovative research for the processing of an uktrasonic image obtained in non-destructive testing (NDT). We also present an algorithm for automatic thresholding segmentation. The image analysis is based on the calculation of cooccurrence matrices. The method we used is the Spatial Grey-Level Dependence Method (SGLDM); it shows the distribution of the intensities of pairs of

Gilles Corneloup; Jospeh Moysan; Isabelle E. Magnin

1996-01-01

83

Body composition: validity of segmental bioelectrical impedance analysis  

Microsoft Academic Search

Bioelectrical impedance analysis (BIA) measures the impedance associated with passage of an alternating cur- rent through the body which is proportional to total body water (TBW) and therefore can provide expedient es- timates of body composition. However, little validity information is available for commercially available bath- room scale type devices which perform whole body estimates from segmental (lower limb) measurements.

Joe LaForgia; Simon M Gunn; Robert T Withers

84

Analysis of recent segmental duplications in the bovine genome  

Technology Transfer Automated Retrieval System (TEKTRAN)

Duplicated sequences are an important source of gene innovation and structural variation within mammalian genomes. We describe the first systematic and genome-wide analysis of segmental duplications in the modern domesticated cattle (Bos taurus). Using two distinct computational analyses, we estimat...

85

Spatiotemporal Analysis of Face Profiles: Detection, Segmentation, and Registration  

Microsoft Academic Search

We use a two-image approach to construct a 3D human facial model for multimedia applications. The images used are those of faces at direct frontal and side views. The selection of the side view from a sequence of facial images is automatically done by applying a spatiotemporal approach to face profile analysis. The extracted side profile is then segmented based

Behzad Dariush; Sing Bang Kang; Keith Waters

1998-01-01

86

Automated target recognition technique for image segmentation and scene analysis  

Microsoft Academic Search

Automated target recognition (ATR) software has been designed to perform image segmentation and scene analysis. Specifically, this software was developed as a package for the Army's Minefield and Reconnaissance and Detector (MIRADOR) program. MIRADOR is an on\\/off road, remote control, multisensor system designed to detect buried and surface- emplaced metallic and nonmetallic antitank mines. The basic requirements for this ATR

Chris W. Baumgart; Christopher A. Ciarcia

1994-01-01

87

ROC analysis of IR segmentation techniques  

NASA Astrophysics Data System (ADS)

Receiver Operating Characteristic (ROC) curves are used to compare the effectiveness of IR image processing techniques. Two non-parametric error estimation techniques (k-Nearest Neighbor and Parzen Window) are used to create estimates of the probability density functions for the data. These pdfs are used in the creation of the ROC curves for both resubstitution and leave-one-out estimates. These estimates generate the upper and lower bounds, respectively, on the ROC curves. The ROC curve analysis is performed on the outputs of various image processing techniques and the resulting ROC curves are used to compare the techniques. Of the image processing techniques used in this thesis, the close minus open (CMO) morphological filter operation produced the best results.

Harrup, Georgia K.

1994-12-01

88

Automatic segmentation of left and right cerebral hemispheres from MRI brain volumes using the graph cuts algorithm  

Microsoft Academic Search

An automated algorithm has been developed to segment stripped (non-brain tissue excluded) T1-weighted MRI brain volumes into left and right cerebral hemispheres and cerebellum+brainstem. The algorithm, which uses the Graph Cuts technique, performs a fully automated segmentation in approximately 30 s following pre-processing. It is robust and accurate and has been tested on datasets from two scanners using different field strengths

Lichen Liang; Kelly Rehm; Roger P. Woods; David A. Rottenberg

2007-01-01

89

Small rural hospitals: an example of market segmentation analysis.  

PubMed

In recent years, market segmentation analysis has shown increased popularity among health care marketers, although marketers tend to focus upon hospitals as sellers. The present analysis suggests that there is merit to viewing hospitals as a market of consumers. Employing a random sample of 741 small rural hospitals, the present investigation sought to determine, through the use of segmentation analysis, the variables associated with hospital success (occupancy). The results of a discriminant analysis yielded a model which classifies hospitals with a high degree of predictive accuracy. Successful hospitals have more beds and employees, and are generally larger and have more resources. However, there was no significant relationship between organizational success and number of services offered by the institution. PMID:10111266

Mainous, A G; Shelby, R L

1991-01-01

90

Four-dimensional image-based treatment planning: Target volume segmentation and dose calculation in the presence of respiratory motion  

SciTech Connect

Purpose: To describe approaches to four-dimensional (4D) treatment planning, including acquisition of 4D-CT scans, target delineation of spatio-temporal image data sets, 4D dose calculations, and their analysis. Methods and Materials: The study included patients with thoracic and hepatocellular tumors. Specialized tools were developed to facilitate visualization, segmentation, and analysis of 4D-CT data: maximum intensity volume to define the extent of lung tumor motion, a 4D browser to examine and dynamically assess the 4D data sets, dose calculations, including respiratory motion, and deformable registration to combine the dose distributions at different points. Results: Four-dimensional CT was used to visualize and quantitatively assess respiratory target motion. The gross target volume contours derived from light breathing scans showed significant differences compared with those extracted from 4D-CT. Evaluation of deformable registration using difference images of original and deformed anatomic maps suggested the algorithm is functionally useful. Thus, calculation of effective dose distributions, including respiratory motion, was implemented. Conclusion: Tools and methods to use 4D-CT data for treatment planning in the presence of respiratory motion have been developed and applied to several case studies. The process of 4D-CT-based treatment planning has been implemented, and technical barriers for its routine use have been identified.

Rietzel, Eike [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States) and Abteilung Biophysik, Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany)]. E-mail: eike@rietzel.net; Chen, George T.Y. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Choi, Noah C. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Willet, Christopher G. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States)

2005-04-01

91

Documented Safety Analysis for the B695 Segment  

SciTech Connect

This Documented Safety Analysis (DSA) was prepared for the Lawrence Livermore National Laboratory (LLNL) Building 695 (B695) Segment of the Decontamination and Waste Treatment Facility (DWTF). The report provides comprehensive information on design and operations, including safety programs and safety structures, systems and components to address the potential process-related hazards, natural phenomena, and external hazards that can affect the public, facility workers, and the environment. Consideration is given to all modes of operation, including the potential for both equipment failure and human error. The facilities known collectively as the DWTF are used by LLNL's Radioactive and Hazardous Waste Management (RHWM) Division to store and treat regulated wastes generated at LLNL. RHWM generally processes low-level radioactive waste with no, or extremely low, concentrations of transuranics (e.g., much less than 100 nCi/g). Wastes processed often contain only depleted uranium and beta- and gamma-emitting nuclides, e.g., {sup 90}Sr, {sup 137}Cs, or {sup 3}H. The mission of the B695 Segment centers on container storage, lab-packing, repacking, overpacking, bulking, sampling, waste transfer, and waste treatment. The B695 Segment is used for storage of radioactive waste (including transuranic and low-level), hazardous, nonhazardous, mixed, and other waste. Storage of hazardous and mixed waste in B695 Segment facilities is in compliance with the Resource Conservation and Recovery Act (RCRA). LLNL is operated by the Lawrence Livermore National Security, LLC, for the Department of Energy (DOE). The B695 Segment is operated by the RHWM Division of LLNL. Many operations in the B695 Segment are performed under a Resource Conservation and Recovery Act (RCRA) operation plan, similar to commercial treatment operations with best demonstrated available technologies. The buildings of the B695 Segment were designed and built considering such operations, using proven building systems, and keeping them as simple as possible while complying with industry standards and institutional requirements. No operations to be performed in the B695 Segment or building system are considered to be complex. No anticipated future change in the facility mission is expected to impact the extent of safety analysis documented in this DSA.

Laycak, D

2008-09-11

92

CLADS analysis deliverables. Volume II. Final report  

SciTech Connect

The functional specification for the Laboratory Technical Information System is contained in Volumes I and II of the CLADS Analysis Deliverables. This specification is the result of applying Structured Analysis and Information Analysis to the Materials Evaluation Laboratory during the analysis phase of this project. Volume I includes 22 data flow diagrams (DFDs), a complete data dictionary containing data elements, data flows, and dialog definitions. Definitions also are included for 77 automated stores or files. These deliverables comprise the user's functional system specification and will be used as input to subsequent project phases, including software design. Volume II of the CLADS Analysis Deliverables covers Data Flow and Element Definitions.

Holland, L.L.; Frede, W.G.; Schleuter, M.E.; Grant, S.E.; Glass, H.H.; Atkinson, K.C.

1985-08-01

93

Survival and Prognostic Analysis of Adjacent Segments after Spinal Fusion  

PubMed Central

Background To examine the survival function and prognostic factors of the adjacent segments based on a second operation after thoracolumbar spinal fusion. Methods This retrospective study reviewed 3,188 patients (3,193 cases) who underwent a thoracolumbar spinal fusion at the author's hospital. Survival analysis was performed on the event of a second operation due to adjacent segment degeneration. The prognostic factors, such as the cause of the disease, surgical procedure, age, gender and number of fusion segments, were examined. Sagittal alignment and the location of the adjacent segment were measured in the second operation cases, and their association with the types of degeneration was investigated. Results One hundred seven patients, 112 cases (3.5%), underwent a second operation due to adjacent segment degeneration. The survival function was 97% and 94% at 5 and 10 years after surgery, respectively, showing a 0.6% linear reduction per year. The significant prognostic factors were old age, degenerative disease, multiple-level fusion and male. Among the second operation cases, the locations of the adjacent segments were the thoracolumbar junctional area and lumbosacral area in 11.6% and 88.4% of cases, respectively. Sagittal alignment was negative or neutral, positive and strongly positive in 47.3%, 38.9%, and 15.7%, respectively. Regarding the type of degeneration, spondylolisthesis or kyphosis, retrolisthesis, and neutral balance in the sagittal view was noted in 13.4%, 36.6%, and 50% of cases, respectively. There was a significant difference according to the location of the adjacent segment (p = 0.000) and sagittal alignment (p = 0.041). Conclusions The survival function of the adjacent segments was 94% at 10 years, which had decreased linearly by 0.6% per a year. The likelihood of a second operation was high in those with old age, degenerative disease, multiple-level fusion and male. There was a tendency for the type of degeneration to be spondylolisthesis or kyphosis in cases of the thoracolumbar junctional area and strongly positive sagittal alignment, but retrolisthesis in cases of the lumbosacral area and neutral or positive sagittal alignment.

Ahn, Dong Ki; Choi, Dae Jung; Kim, Kwan Soo; Yang, Seung Jin

2010-01-01

94

Three-dimensional model-guided segmentation and analysis of medical images  

NASA Astrophysics Data System (ADS)

Automated or semi-automated analysis and labeling of structural brain images, such as magnetic resonance (MR) and computed tomography, is desirable for a number of reasons. Quantification of brain volumes can aid in the study of various diseases and the affect of various drug regimes. A labeled structural image, when registered with a functional image such as positron emission tomography or single photon emission computed tomography, allows the quantification of activity in various brain subvolumes such as the major lobes. Because even low resolution scans (7.5 to 8.0 mm slices) have 15 to 17 slices in order to image the entire head of the subject hand segmentation of these slices is a very laborious process. However, because of the spatial complexity of many of the brain structures notably the ventricles, automatic segmentation is not a simple undertaking. In order to accurately segment a structure such as the ventricles we must have a model of equal complexity to guide the segmentation. Also, we must have a model which can incorporate the variability among different subjects from a pre-specified group. Analysis of MR brain scans is accomplished by utilizing the data from T2 weighted and proton density images to isolate the regions of interest. Identification is then done automatically with the aid of a composite model formed from the operator assisted segmentation of MR scans of subjects from the same group. We describe the construction of the model and demonstrate its use in the segmentation and labeling of the ventricles in the brain.

Arata, Louis K.; Dhawan, Atam P.; Broderick, Joseph; Gaskill-Shipley, Mary

1992-06-01

95

Fractal Segmentation and Clustering Analysis for Seismic Time Slices  

Microsoft Academic Search

Fractal analysis has become part of the standard approach for quantifying texture on gray-tone or colored images. In this research we introduce a multi-stage fractal procedure to segment, classify and measure the clustering patterns on seismic time slices from a 3-D seismic survey. Five fractal classifiers (c1)-(c5) were designed to yield standardized, unbiased and precise measures of the clustering of

G. Ronquillo; K. Oleschko; G. Korvin; R. D. Arizabalo

2002-01-01

96

Automatic segmentation and quantitative analysis of the articular cartilages from magnetic resonance images of the knee.  

PubMed

In this paper, we present a segmentation scheme that automatically and accurately segments all the cartilages from magnetic resonance (MR) images of nonpathological knees. Our scheme involves the automatic segmentation of the bones using a three-dimensional active shape model, the extraction of the expected bone-cartilage interface (BCI), and cartilage segmentation from the BCI using a deformable model that utilizes localization, patient specific tissue estimation and a model of the thickness variation. The accuracy of this scheme was experimentally validated using leave one out experiments on a database of fat suppressed spoiled gradient recall MR images. The scheme was compared to three state of the art approaches, tissue classification, a modified semi-automatic watershed algorithm and nonrigid registration (B-spline based free form deformation). Our scheme obtained an average Dice similarity coefficient (DSC) of (0.83, 0.83, 0.85) for the (patellar, tibial, femoral) cartilages, while (0.82, 0.81, 0.86) was obtained with a tissue classifier and (0.73, 0.79, 0.76) was obtained with nonrigid registration. The average DSC obtained for all the cartilages using a semi-automatic watershed algorithm (0.90) was slightly higher than our approach (0.89), however unlike this approach we segment each cartilage as a separate object. The effectiveness of our approach for quantitative analysis was evaluated using volume and thickness measures with a median volume difference error of (5.92, 4.65, 5.69) and absolute Laplacian thickness difference of (0.13, 0.24, 0.12) mm. PMID:19520633

Fripp, Jurgen; Crozier, Stuart; Warfield, Simon K; Ourselin, Sébastien

2009-06-10

97

Automatic Segmentation and Quantitative Analysis of the Articular Cartilages From Magnetic Resonance Images of the Knee  

PubMed Central

In this paper, we present a segmentation scheme that automatically and accurately segments all the cartilages from magnetic resonance (MR) images of nonpathological knees. Our scheme involves the automatic segmentation of the bones using a three-dimensional active shape model, the extraction of the expected bone-cartilage interface (BCI), and cartilage segmentation from the BCI using a deformable model that utilizes localization, patient specific tissue estimation and a model of the thickness variation. The accuracy of this scheme was experimentally validated using leave one out experiments on a database of fat suppressed spoiled gradient recall MR images. The scheme was compared to three state of the art approaches, tissue classification, a modified semi-automatic watershed algorithm and nonrigid registration (B-spline based free form deformation). Our scheme obtained an average Dice similarity coefficient (DSC) of (0.83, 0.83, 0.85) for the (patellar, tibial, femoral) cartilages, while (0.82, 0.81, 0.86) was obtained with a tissue classifier and (0.73, 0.79, 0.76) was obtained with nonrigid registration. The average DSC obtained for all the cartilages using a semi-automatic watershed algorithm (0.90) was slightly higher than our approach (0.89), however unlike this approach we segment each cartilage as a separate object. The effectiveness of our approach for quantitative analysis was evaluated using volume and thickness measures with a median volume difference error of (5.92, 4.65, 5.69) and absolute Laplacian thickness difference of (0.13, 0.24, 0.12) mm.

Fripp, Jurgen; Crozier, Stuart; Warfield, Simon K.; Ourselin, Sebastien

2010-01-01

98

Analysis of recent segmental duplications in the bovine genome  

PubMed Central

Background Duplicated sequences are an important source of gene innovation and structural variation within mammalian genomes. We performed the first systematic and genome-wide analysis of segmental duplications in the modern domesticated cattle (Bos taurus). Using two distinct computational analyses, we estimated that 3.1% (94.4 Mb) of the bovine genome consists of recently duplicated sequences (? 1 kb in length, ? 90% sequence identity). Similar to other mammalian draft assemblies, almost half (47% of 94.4 Mb) of these sequences have not been assigned to cattle chromosomes. Results In this study, we provide the first experimental validation large duplications and briefly compared their distribution on two independent bovine genome assemblies using fluorescent in situ hybridization (FISH). Our analyses suggest that the (75-90%) of segmental duplications are organized into local tandem duplication clusters. Along with rodents and carnivores, these results now confidently establish tandem duplications as the most likely mammalian archetypical organization, in contrast to humans and great ape species which show a preponderance of interspersed duplications. A cross-species survey of duplicated genes and gene families indicated that duplication, positive selection and gene conversion have shaped primates, rodents, carnivores and ruminants to different degrees for their speciation and adaptation. We identified that bovine segmental duplications corresponding to genes are significantly enriched for specific biological functions such as immunity, digestion, lactation and reproduction. Conclusion Our results suggest that in most mammalian lineages segmental duplications are organized in a tandem configuration. Segmental duplications remain problematic for genome and assembly and we highlight genic regions that require higher quality sequence characterization. This study provides insights into mammalian genome evolution and generates a valuable resource for cattle genomics research.

2009-01-01

99

Analysis of adjacent segment degeneration with laminectomy above a fused lumbar segment.  

PubMed

Although recent data suggests that lumbar fusion with decompression contributes to some marginal acceleration of adjacent segment degeneration (ASD), few studies have evaluated whether it is safe to perform a laminectomy above a fused segment. This study investigates the hypothesis that laminectomy above a fused lumbar segment does not increase the incidence of ASD, and assesses the benefits and risks of performing a laminectomy above a lumbar fusion. A retrospective review of 171 patients who underwent decompression and instrumented fusion of the lumbar spine was performed to analyze the association between ASD and laminectomy above the fused lumbar segment. Patients were divided into two groups - one group with instrumented fusion alone and the other group with instrumented fusion plus laminectomy above the fused segment. Of the 171 patients, 34 underwent additional decompressive laminectomy above the fused segment. There was a significant increase in ASD incidence as well as progression of ASD grade in both groups. There was no significant increase in ASD in patients with decompressive laminectomy above the fused lumbar segment compared to patients with laminectomy limited to the fused segment. This retrospective review of 171 patients who underwent decompression and instrumented fusion with follow-up radiographs demonstrates that laminectomy decompression above a fused segment does not significantly increase radiographic ASD. There is, however, a significant increase in ASD over time, which was observed throughout the entire cohort likely representing a natural progression of lumbar spondylosis above the fusion segment. PMID:23891120

Gard, Andrew P; Klopper, Hendrik B; Doran, Stephen E; Hellbusch, Leslie C

2013-07-25

100

Monotone Signal Segments Analysis as a novel method of breath detection and breath-to-breath interval analysis in rat  

PubMed Central

We applied a novel approach to respiratory waveform analysis - Monotone Signal Segments Analysis (MSSA) on 6-h recordings of respiratory signals in rats. To validate MSSA as a respiratory signal analysis tool we tested it by detecting: breaths and breath-to-breath intervals; by detecting respiratory timing and volume modes; and by detecting changes in respiratory pattern caused by lesions of monoaminergic systems in rats. MSSA differentiated three respiratory timing (tachypneic, eupneic, bradypneic-apneic), and three volume (artifacts, normovolemic, hypervolemic-sighs) modes. Lesion-induced respiratory pattern modulation was visible as shifts in the distributions of monotone signal segment amplitudes, and of breath-to-breath intervals. Specifically, noradrenergic lesion induced an increase in mean volume (p ? 0.03), with no change of the mean breath-to-breath interval duration (p ? 0.06). MSSA of timing modes detected noradrenergic lesion-induced interdependent changes in the balance of eupneic (decrease; p ? 0.02), and tachypneic (an increase; p ? 0.02) breath intervals with respect to control. In terms of breath durations within each timing mode, there was a tendency toward prolongation of the eupneic (p ? 0.08) and bradypneic-apneic (p ? 0.06) intervals. These results demonstrate that MSSA is sensitive to subtle shifts in respiratory rhythmogenesis not detectable by simple respiratory pattern descriptive statistics. MSSA represents a potentially valuable new tool for investigations of respiratory pattern control.

Bojic, Tijana; Saponjic, Jasna; Radulovacki, Miodrag; Carley, David W.; Kalauzi, Aleksandar

2008-01-01

101

CLADS Analysis Deliverables. Volume I. Final report  

SciTech Connect

The functional specification for the Laboratory Technical Information System is contained in Volumes I and II of the CLADS Analysis Deliverables. This specification is the result of applying Structured Analysis and Information Analysis to the Materials Evaluation Laboratory during the analysis phase of this project. Volume I includes 22 data flow diagrams (DFDs), a complete data dictionary containing data elements, data flows, and dialog definitions. Definitions also are included for 77 automated stores or files. These deliverables comprise the user's functional system specification and will be used as input to subsequent project phases, including software design. Volume I of the CLADS Analysis Deliverables contains Physical diagrams, Mini Specs, Automated Files, Manual Stores, and Dialog Definitions.

Holland, L.L.; Frede, W.G.; Schleuter, M.E.; Grant, S.E.; Glass, H.H.; Atkinson, K.C.

1985-08-01

102

Assessment of volume segmentation in radiotherapy of adolescents; a treatment planning study by the Swedish Workgroup for Paediatric Radiotherapy.  

PubMed

Background and purpose. The variability in target delineation for similar cases between centres treating paediatric and adolescent patients, and the apparent differences in interpretation of radiotherapy guidelines in the treatment protocols encouraged us to perform a dummy-run study as a part of our quality assurance work. The aim was to identify and quantify differences in the segmentation of target volumes and organs at risk (OARs) and to analyse the treatment plans and dose distributions. Materials and methods. Four patient cases were selected: Wilm's tumour, Hodgkin's disease, rhabdomyosarcoma of the prostate and chordoma of the skull base. The five participating centres received the same patient-related material. They introduced the cases in their treatment planning system, delineated target volumes and OARs and created treatment plans. Dose-volume histograms were retrieved for relevant structures and volumes and dose metrics were derived and compared, e.g. target volumes and their concordance, dose homogeneity index (HI), treated and irradiated volumes, remaining volume at risk and relevant Vx and Dx values. Results. We found significant differences in target segmentation in the majority of the cases. The planning target volumes (PTVs) varied two- to four-fold and conformity indices were in the range of 0.3-0.6. This resulted in large variations in dose distributions to OARs as well as in treated and irradiated volumes even though the treatment plans showed good conformity to the PTVs. Potential reasons for the differences in target delineation were analysed. Conclusion. Considerations of the growing child and difficulties in interpretation of the radiotherapy information in the treatment protocols were identified as reasons for the variation. As a result, clarified translated detailed radiotherapy guidelines for paediatric/adolescent patients have been recognised as a way to reduce this variation. PMID:23577745

Kristensen, Ingrid; Agrup, Måns; Bergström, Per; Engellau, Jacob; Haugen, Hedda; Martinsson, Ulla; Nilsson, Kristina; Taheri-Kadkhoda, Zahra; Lindh, Jack; Nilsson, Per

2013-04-12

103

Discrete-time event history analysis using segmented hazards.  

PubMed

Event history analysis is a means of explaining variation in the timing of events in individual life histories. This article describes methods for overcoming two difficult problems likely to be encountered in applications of event history analysis to studies of aging and human development. First, in many studies the ages of occurrence of critical life events are recorded in discrete units such as years, but the probability distributions of life events are usually specified in continuous-time form. We show how to estimate models for discrete-time data based on an underlying continuous-time specification. Second, the standard distributions for life events often fail to capture the complex age-dependence seen in actual data. We show how to construct a model using segmented hazards, that is, a composite of different functions for different segments of time. To illustrate these points, we study the age of first intercourse of 11,883 subjects from the National Longitudinal Study of Youth. PMID:1820290

Gardner, W; Meyer, M; Ketterlinus, R

1991-01-01

104

Dextrocardia--value of segmental analysis in its categorisation.  

PubMed Central

Dextrocardia can be defined as a heart in the right chest with the major axis to the right. This definition, however, conveys no information regarding the chamber arrangements and internal anatomy of the heart. Of 40 patients satisfying this definition in the files of the Brompton Hospital, 33 had angiocardiographic data adequate for complete analysis in terms of connections, relations, and morphology of cardiac segments. They form the subject of this report. There were 16 (48%) patients with situs solitus, 11 (33%) with situs inversus, and six (18%) with situs ambiguus. Of the cases of situs ambiguus, four exhibited laevoisomerism and two dextroisomerism. Of the 16 patients with situs solitus, six had two ventricles and 10 had univentricular hearts; two patients had concordant and three discordant ventriculoarterial connections, seven had double outlet ventricle, and four a single outlet heart. Of the 11 patients with situs inversus, nine had two ventricles and two a univentricular heart of right ventricular type; the arterial connection was concordant in two, discordant in two, double outlet in six, and single outlet in one. Of the six patients with situs ambiguus and laevo or dextroisomerism, four had two ventricles, and two univentricular hearts; the arterial connection was concordant in one, double outlet in three, and single outlet in two. Segmental analysis and the use of basic descriptive terms are essential to define the complex anatomy of such hearts. Images

Calcaterra, G; Anderson, R H; Lau, K C; Shinebourne, E A

1979-01-01

105

Automated target recognition technique for image segmentation and scene analysis  

NASA Astrophysics Data System (ADS)

Automated target recognition (ATR) software has been designed to perform image segmentation and scene analysis. Specifically, this software was developed as a package for the Army's Minefield and Reconnaissance and Detector (MIRADOR) program. MIRADOR is an on/off road, remote control, multisensor system designed to detect buried and surface- emplaced metallic and nonmetallic antitank mines. The basic requirements for this ATR software were the following: (1) an ability to separate target objects from the background in low signal-noise conditions; (2) an ability to handle a relatively high dynamic range in imaging light levels; (3) the ability to compensate for or remove light source effects such as shadows; and (4) the ability to identify target objects as mines. The image segmentation and target evaluation was performed using an integrated and parallel processing approach. Three basic techniques (texture analysis, edge enhancement, and contrast enhancement) were used collectively to extract all potential mine target shapes from the basic image. Target evaluation was then performed using a combination of size, geometrical, and fractal characteristics, which resulted in a calculated probability for each target shape. Overall results with this algorithm were quite good, though there is a tradeoff between detection confidence and the number of false alarms. This technology also has applications in the areas of hazardous waste site remediation, archaeology, and law enforcement.

Baumgart, Chris W.; Ciarcia, Christopher A.

1994-03-01

106

Modern Trends in Activation Analysis. Volume 1.  

National Technical Information Service (NTIS)

A conference on Modern Trends in Activation Analysis was held at the National Bureau of Standards, October 7-11, 1968. This volume contains texts of two invited plenary lectures, one on the applications of activation analysis and one on radiochemical sepa...

J. R. DeVoe P. D. LaFleur

1969-01-01

107

Automated image segmentation for breast analysis using infrared images.  

PubMed

In order to realize a fully automated thermogram analysis package for breast cancer detection, it is necessary to identify the region of interest in the thermal image prior to analysis. A nearly fully automated approach is outlined that is able to successfully locate the breast regions in most of the images analyzed. The approach consists of a sequence of Canny edge detectors to determine the body boundaries and to isolate the most likely candidates for the bottom breast boundary. Three different strategies for identifying the bottom breast boundary are investigated: a variation of the Hough transform to identify the curved edges in the image, an algorithm used to detect the longest connected edges that are not part of the body boundary, and a third approach involving the density of detected edges in the breast region. The last two methods show great promise in successfully segmenting the breasts. PMID:17272041

Scales, N; Herry, C; Frize, M

2004-01-01

108

3-D segmentation of retinal blood vessels in spectral-domain OCT volumes of the optic nerve head  

NASA Astrophysics Data System (ADS)

Segmentation of retinal blood vessels can provide important information for detecting and tracking retinal vascular diseases including diabetic retinopathy, arterial hypertension, arteriosclerosis and retinopathy of prematurity (ROP). Many studies on 2-D segmentation of retinal blood vessels from a variety of medical images have been performed. However, 3-D segmentation of retinal blood vessels from spectral-domain optical coherence tomography (OCT) volumes, which is capable of providing geometrically accurate vessel models, to the best of our knowledge, has not been previously studied. The purpose of this study is to develop and evaluate a method that can automatically detect 3-D retinal blood vessels from spectral-domain OCT scans centered on the optic nerve head (ONH). The proposed method utilized a fast multiscale 3-D graph search to segment retinal surfaces as well as a triangular mesh-based 3-D graph search to detect retinal blood vessels. An experiment on 30 ONH-centered OCT scans (15 right eye scans and 15 left eye scans) from 15 subjects was performed, and the mean unsigned error in 3-D of the computer segmentations compared with the independent standard obtained from a retinal specialist was 3.4 +/- 2.5 voxels (0.10 +/- 0.07 mm).

Lee, Kyungmoo; Abràmoff, Michael D.; Niemeijer, Meindert; Garvin, Mona K.; Sonka, Milan

2010-03-01

109

Market segment analysis to target young adult wine drinkers  

Microsoft Academic Search

Consumer segmentation in the wine industry takes on many forms: demographic, geographic, behavioral, and others. In the United States, one of the most promising new demographic segments is the Millennial or Echo Boomer segment, which is being targeted by many consumer industries due to its size and buying power. For the wine industry, this group currently fits the legal drinking

Elizabeth C. Thach; Janeen E. Olsen

2006-01-01

110

Improving the clinical correlation of multiple sclerosis black hole volume change by paired-scan analysis.  

PubMed

The change in T 1-hypointense lesion ("black hole") volume is an important marker of pathological progression in multiple sclerosis (MS). Black hole boundaries often have low contrast and are difficult to determine accurately and most (semi-)automated segmentation methods first compute the T 2-hyperintense lesions, which are a superset of the black holes and are typically more distinct, to form a search space for the T 1w lesions. Two main potential sources of measurement noise in longitudinal black hole volume computation are partial volume and variability in the T 2w lesion segmentation. A paired analysis approach is proposed herein that uses registration to equalize partial volume and lesion mask processing to combine T 2w lesion segmentations across time. The scans of 247 MS patients are used to compare a selected black hole computation method with an enhanced version incorporating paired analysis, using rank correlation to a clinical variable (MS functional composite) as the primary outcome measure. The comparison is done at nine different levels of intensity as a previous study suggests that darker black holes may yield stronger correlations. The results demonstrate that paired analysis can strongly improve longitudinal correlation (from -0.148 to -0.303 in this sample) and may produce segmentations that are more sensitive to clinically relevant changes. PMID:24179734

Tam, Roger C; Traboulsee, Anthony; Riddehough, Andrew; Li, David K B

2012-09-05

111

Improving the clinical correlation of multiple sclerosis black hole volume change by paired-scan analysis?  

PubMed Central

The change in T1-hypointense lesion (“black hole”) volume is an important marker of pathological progression in multiple sclerosis (MS). Black hole boundaries often have low contrast and are difficult to determine accurately and most (semi?)automated segmentation methods first compute the T2-hyperintense lesions, which are a superset of the black holes and are typically more distinct, to form a search space for the T1w lesions. Two main potential sources of measurement noise in longitudinal black hole volume computation are partial volume and variability in the T2w lesion segmentation. A paired analysis approach is proposed herein that uses registration to equalize partial volume and lesion mask processing to combine T2w lesion segmentations across time. The scans of 247 MS patients are used to compare a selected black hole computation method with an enhanced version incorporating paired analysis, using rank correlation to a clinical variable (MS functional composite) as the primary outcome measure. The comparison is done at nine different levels of intensity as a previous study suggests that darker black holes may yield stronger correlations. The results demonstrate that paired analysis can strongly improve longitudinal correlation (from -0.148 to -0.303 in this sample) and may produce segmentations that are more sensitive to clinically relevant changes.

Tam, Roger C.; Traboulsee, Anthony; Riddehough, Andrew; Li, David K.B.

2012-01-01

112

The development and testing of a digital PET phantom for the evaluation of tumor volume segmentation techniques.  

PubMed

Methods for accurate tumor volume segmentation of positron emission tomography (PET) images have been under investigation in recent years partly as a result of the increased use of PET in radiation treatment planning (RTP). None of the developed automated or semiautomated segmentation methods, however, has been shown reliable enough to be regarded as the standard. One reason for this is that there is no source of well characterized and reliable test data for evaluating such techniques. The authors have constructed a digital tumor phantom to address this need. The phantom was created using the Zubal phantom as input to the SimSET software used for PET simulations. Synthetic tumors were placed in the lung of the Zubal phantom to provide the targets for segmentation. The authors concentrated on the lung, since much of the interest to include PET in RTP is for nonsmall cell lung cancer. Several tests were performed on the phantom to ensure its close resemblance to clinical PET scans. The authors measured statistical quantities to compare image intensity distributions from regions-of-interest (ROIs) placed in the liver, the lungs, and tumors in phantom and clinical reconstructions. Using ROIs they also made measurements of autocorrelation functions to ensure the image texture is similar in clinical and phantom data. The authors also compared the intensity profile and appearance of real and simulated uniform activity spheres within uniform background. These measurements, along with visual comparisons of the phantom with clinical scans, indicate that the simulated phantom mimics reality quite well. Finally, they investigate and quantify the relationship between the threshold required to segment a tumor and the inhomogeneity of the tumor's image intensity distribution. The tests and various measurements performed in this study demonstrate how the phantom can offer a reliable way of testing and investigating tumor volume segmentation in PET. PMID:18697557

Aristophanous, Michalis; Penney, Bill C; Pelizzari, Charles A

2008-07-01

113

Markov random field and Gaussian mixture for segmented MRI-based partial volume correction in PET  

NASA Astrophysics Data System (ADS)

In this paper we propose a segmented magnetic resonance imaging (MRI) prior-based maximum penalized likelihood deconvolution technique for positron emission tomography (PET) images. The model assumes the existence of activity classes that behave like a hidden Markov random field (MRF) driven by the segmented MRI. We utilize a mean field approximation to compute the likelihood of the MRF. We tested our method on both simulated and clinical data (brain PET) and compared our results with PET images corrected with the re-blurred Van Cittert (VC) algorithm, the simplified Guven (SG) algorithm and the region-based voxel-wise (RBV) technique. We demonstrated our algorithm outperforms the VC algorithm and outperforms SG and RBV corrections when the segmented MRI is inconsistent (e.g. mis-segmentation, lesions, etc) with the PET image.

Bousse, Alexandre; Pedemonte, Stefano; Thomas, Benjamin A.; Erlandsson, Kjell; Ourselin, Sébastien; Arridge, Simon; Hutton, Brian F.

2012-10-01

114

Markov random field and Gaussian mixture for segmented MRI-based partial volume correction in PET.  

PubMed

In this paper we propose a segmented magnetic resonance imaging (MRI) prior-based maximum penalized likelihood deconvolution technique for positron emission tomography (PET) images. The model assumes the existence of activity classes that behave like a hidden Markov random field (MRF) driven by the segmented MRI. We utilize a mean field approximation to compute the likelihood of the MRF. We tested our method on both simulated and clinical data (brain PET) and compared our results with PET images corrected with the re-blurred Van Cittert (VC) algorithm, the simplified Guven (SG) algorithm and the region-based voxel-wise (RBV) technique. We demonstrated our algorithm outperforms the VC algorithm and outperforms SG and RBV corrections when the segmented MRI is inconsistent (e.g. mis-segmentation, lesions, etc) with the PET image. PMID:23023073

Bousse, Alexandre; Pedemonte, Stefano; Thomas, Benjamin A; Erlandsson, Kjell; Ourselin, Sébastien; Arridge, Simon; Hutton, Brian F

2012-10-01

115

A New Method for Volume Segmentation of PET Images, Based on Possibility Theory  

Microsoft Academic Search

F-fluorodeoxyglucose positron emission tomog- raphy (18FDG PET) has become an essential technique in oncology. Accurate segmentation and uptake quantification are crucial in order to enable objective follow-up, the optimization of radiotherapy planning, and therapeutic evaluation. We have designed and evaluated a new, nearly automatic and operator-in- dependent segmentation approach. This incorporated possibility theory, in order to take into account the

Anne-Sophie Dewalle-Vignion; Nacim Betrouni; Renaud Lopes; Damien Huglo; Simon Stute; Maximilien Vermandel

2011-01-01

116

REACH. Teacher's Guide, Volume III. Task Analysis.  

ERIC Educational Resources Information Center

|Designed for use with individualized instructional units (CE 026 345-347, CE 026 349-351) in the electromechanical cluster, this third volume of the postsecondary teacher's guide presents the task analysis which was used in the development of the REACH (Refrigeration, Electro-Mechanical, Air Conditioning, Heating) curriculum. The major blocks of…

Morris, James Lee; And Others

117

ST-segment re-elevation unrelated to left ventricular ejection fraction or volume after anterior wall acute myocardial infarction treated with successful reperfusion  

Microsoft Academic Search

Ventricular remodeling is a major determinant of the long-term prognosis of patients with acute myocardial infarction (AMI). No previous study examined the relation of ST-segment re-elevation to left ventricular (LV) volume and function in patients with successful reperfusion. We examined the relation of ST-segment re-elevation to LV function and volume indices in 51 patients with anterior wall AMI who underwent

Shigeru Matano; Kohichiro Iwasaki; Shozo Kusachi; Takashi Murakami; Sekiko Kurazono; Hirosuke Yamaji; Hiromi Hamamoto; Toshiyuki Takamura; Kazuyoshi Hina; Takao Tsuji

2002-01-01

118

Image sequence segmentation via heuristic texture analysis and region tracking  

Microsoft Academic Search

We develop a method for automatic segmentation of natural video sequences. The method is based on low-level spatial and temporal analyses. It features three designs to help facilitate good region segmentation while keeping the computational complexity at a reasonable level. Firstly, a preliminary seed-area identification and a final re-segmentation process are performed on each video frame to help region tracking.

Yih-Haw Jan; David W. Lin

2002-01-01

119

Body composition: validity of segmental bioelectrical impedance analysis.  

PubMed

Bioelectrical impedance analysis (BIA) measures the impedance associated with passage of an alternating current through the body which is proportional to total body water (TBW) and therefore can provide expedient estimates of body composition. However, little validity information is available for commercially available bathroom scale type devices which perform whole body estimates from segmental (lower limb) measurements. This study therefore compared body composition estimates between a commercially available segmental BIA device (Tanita BC-532) and four compartment criterion values. Body composition of nine males and nine females (mean +/- SD: 37.7 +/- 18.7 yr; 170.7 +/- 5.3 cm; 68.38 +/- 9.7 kg) was determined via BIA and a four compartment model incorporating measures of body density, TBW and bone mineral mass. While the mean %BF and fat free mass (FFM) values for both methods were not significantly different, considerable intra-individual differences were observed. BIA values varied from the four compartment values by -3.0 to 4.4 %BF and -3.3 to 1.9 kg FFM. The BIA estimates of TBW were significantly different from the criterion measures and intraindividual differences displayed a large range (-0.6 to 3.6 kg). Significant underestimations of TBW via BIA are concerning given that this is the parameter initially established by this method. Furthermore, the BIA data resulted in a FFM hydration value of 68.5% which was significantly (p<0.001) lower than the four compartment value of 72.0%. In conclusion, the BIA device tested displayed poor individual accuracy for the estimation of body composition compared with a four compartment criterion method. PMID:19114394

LaForgia, Joe; Gunn, Simon; Withers, Robert T

2008-01-01

120

A Semi-automatic Image Segmentation Method for Extraction of Brain Volume from In Vivo Mouse Head Magnetic Resonance Imaging using Constraint Level Sets  

PubMed Central

In vivo magnetic resonance imaging (MRI) of mouse brain has been widely used to non-invasively monitor disease progression and/or therapeutic effects in murine models of human neurodegenerative disease. Segmentation of MRI to differentiate brain from non-brain tissue (usually referred to as brain extraction) is required for many MRI data processing and analysis methods, including coregistration, statistical parametric analysis, mapping to brain atlas and histology. This paper presents a semi-automatic brain extraction technique based on a level set method with the incorporation of user-defined constraints. The constraints are derived from the prior knowledge of brain anatomy by defining brain boundary on orthogonal planes of the MRI. Constraints are incorporated in the level set method by spatially varying the weighting factors of the internal and external forces and modifying the image gradient (edge) map. Both two-dimensional multi-slice and three-dimensional versions of the brain extraction technique were developed and applied to MRI data with minimal brain/non-brain contrast T1-weighted (T1-wt) FLASH and maximized contrast T2-weighted (T2-wt) RARE. Results were evaluated by calculating the overlap measure (OM) between the automatically segmented and manually traced brain volumes. Results demonstrate that this technique accurately extracts the brain volume (mean OM = 94 %) and consistently outperformed the region growing method applied to the T2-wt RARE MRI (mean OM = 81 %). This method not only successfully extracts the mouse brain in low and high contrast MRI, but can also be used to segment other organs and tissues.

Uberti, Mariano G.; Boska, Michael D.; Liu, Yutong

2009-01-01

121

Seismic Analysis of Segmental Retaining Walls.?II: Effects of Facing Details  

Microsoft Academic Search

This paper describes a finite-element analysis of two 6-m-high segmental walls, subjected to seismic loading, with special attention to connection performance and permanent deformation of the facing. The first segmental wall uses concrete facing blocks with pins, and the second wall uses the same concrete blocks but without pins. The analysis provides some insight into the behavior of segmental walls,

M. B. Helwany; David McCallen

2001-01-01

122

Fractal Segmentation and Clustering Analysis for Seismic Time Slices  

NASA Astrophysics Data System (ADS)

Fractal analysis has become part of the standard approach for quantifying texture on gray-tone or colored images. In this research we introduce a multi-stage fractal procedure to segment, classify and measure the clustering patterns on seismic time slices from a 3-D seismic survey. Five fractal classifiers (c1)-(c5) were designed to yield standardized, unbiased and precise measures of the clustering of seismic signals. The classifiers were tested on seismic time slices from the AKAL field, Cantarell Oil Complex, Mexico. The generalized lacunarity (c1), fractal signature (c2), heterogeneity (c3), rugosity of boundaries (c4) and continuity resp. tortuosity (c5) of the clusters are shown to be efficient measures of the time-space variability of seismic signals. The Local Fractal Analysis (LFA) of time slices has proved to be a powerful edge detection filter to detect and enhance linear features, like faults or buried meandering rivers. The local fractal dimensions of the time slices were also compared with the self-affinity dimensions of the corresponding parts of porosity-logs. It is speculated that the spectral dimension of the negative-amplitude parts of the time-slice yields a measure of connectivity between the formation's high-porosity zones, and correlates with overall permeability.

Ronquillo, G.; Oleschko, K.; Korvin, G.; Arizabalo, R. D.

2002-05-01

123

Seismic Analysis of Segmental Retaining Walls. I: Model Verification  

Microsoft Academic Search

Block-faced geosynthetic reinforced soil retaining walls, referred to as ''segmental'' retaining walls, have been extensively used in recent years as permanent civil engineering structures. The disjointed concrete facing blocks are held together through interface friction and concrete keys or mechanical connectors. Because of the disjointed nature of the facing blocks, the design of the segmental wall must consider the available

Sam M. B. Helwany; M. Budhu; David McCallen

2001-01-01

124

Neurological complications in segmental spinal instrumentation: analysis of 750 patients  

Microsoft Academic Search

The authors report on neurological damage caused by the use of sublaminar segmental fixation in the correction of vertebral deformities. Three groups were reviewed: 600 patients instrumented with Harrington rods and segmental wiring, 50 patients treated with the Hartshill system and 100 patients instrumented with Luque bars. All of the patients were operated on using sublaminar wiring fixation. We report

S. Cervellati; N. Bettini; T. Bianco; P. Parisini

1996-01-01

125

Evolving Image Segmentations for the Analysis of Video Sequences  

Microsoft Academic Search

A methodology for the segmentation of successive frames of a video sequence is presented. Traditional methods, treating each frame in isolation, are computationally expensive, ignore potentially useful information derived from previous frames, and can lead to instabilities in the segmentation over the sequence. The approach developed here, based on the Region Competition algorithm (Zhu and Yuille, IEEE Trans. PAMI, 1996),

A. A. Clark; Barry T. Thomas

2001-01-01

126

Estimation of body composition in Chinese and British men by ultrasonographic assessment of segmental adipose tissue volume.  

PubMed Central

It has been shown that ultrasonographic measurements can be used to predict body composition in adults. The purpose of this study was to assess the relationship between ultrasonograph and caliper (SKF) measurements of subcutaneous adipose tissue thickness in athletic Caucasian (English, E) and Asian (Chinese, C) men against estimates of body composition determined from hydrodensitometry (HYD). The usefulness of a proposed ultrasonographic method of estimating lean and fat proportions in the upper and lower limbs was also evaluated as a potential method of predicting body composition. Ultrasonography (US) was used to measure adipose and skin thickness at the following sites: biceps, triceps, subscapular, suprailiac, abdominal, pectoral, thigh and calf. Caliper measurements were also made at the above sites. Subcutaneous fat thickness and segmental radius were measured directly from the display screen of the ultrasonic scanner (Aloka 500 SD). By applying the geometry of a cone, the proximal and distal radii of the upper arm and upper leg were used to calculate the proportionate volumes of adipose tissue. The best correlations for US and SKF were obtained at the quadriceps, subscapular and pectoral sites for E (r = 0.96, 0.93 and 0.90, respectively) and at the quadriceps, calf and abdominal sites for C (r = 0.90, 0.81 and 0.75, respectively). The best ultrasonographic predictor of the percentage fat in both groups was the percentage adipose tissue volume in the upper leg (r = 0.83 and 0.79 for C and E, respectively). Stepwise multiple regression analysis indicated that the prediction of percentage fat was improved by the addition of the ultrasonographic abdomen measurement in both groups: Chinese sample: %fat = %fat(leg) (0.491) + US abdomen (0.337) + 0.95 ( R = 0.89, s.e.e. = 1.9%); English sample: %fat = %fat(leg) (0.435) + US abdomen (0.230) - 0.765 ( R = 0.80, s.e.e. = 3.6%). It is concluded that ultrasonographic measurements of subcutaneous adipose tissue and volumetric assessment of percentage adipose tissue in the thigh are useful estimates of body composition in athletic English and Chinese males. Images Figure 1 Figure 2 Figure 3 p13-a

Eston, R; Evans, R; Fu, F

1994-01-01

127

Fusing Markov random fields with anatomical knowledge and shape-based analysis to segment multiple sclerosis white matter lesions in magnetic resonance images of the brain  

NASA Astrophysics Data System (ADS)

This paper proposes an image analysis system to segment multiple sclerosis lesions of magnetic resonance (MR) brain volumes consisting of 3 mm thick slices using three channels (images showing T1-, T2- and PD -weighted contrast). The method uses the statistical model of Markov Random Fields (MRF) both at low and high levels. The neighborhood system used in this MRF is defined in three types: (1) Voxel to voxel: a low-level heterogeneous neighborhood system is used to restore noisy images. (2) Voxel to segment: a fuzzy atlas, which indicates the probability distribution of each tissue type in the brain, is registered elastically with the MRF. It is used by the MRF as a-priori knowledge to correct miss-classified voxels. (3) Segment to segment: Remaining lesion candidates are processed by a feature based classifier that looks at unary and neighborhood information to eliminate more false positives. An expert's manual segmentation was compared with the algorithm.

AlZubi, Stephan; Toennies, Klaus D.; Bodammer, N.; Hinrichs, Herman

2002-05-01

128

Automatic brain tumor segmentation  

NASA Astrophysics Data System (ADS)

A system that automatically segments and labels complete glioblastoma-multiform tumor volumes in magnetic resonance images of the human brain is presented. The magnetic resonance images consist of three feature images (T1- weighted, proton density, T2-weighted) and are processed by a system which integrates knowledge-based techniques with multispectral analysis and is independent of a particular magnetic resonance scanning protocol. Initial segmentation is performed by an unsupervised clustering algorithm. The segmented image, along with cluster centers for each class are provided to a rule-based expert system which extracts the intra-cranial region. Multispectral histogram analysis separates suspected tumor from the rest of the intra-cranial region, with region analysis used in performing the final tumor labeling. This system has been trained on eleven volume data sets and tested on twenty-two unseen volume data sets acquired from a single magnetic resonance imaging system. The knowledge-based tumor segmentation was compared with radiologist-verified `ground truth' tumor volumes and results generated by a supervised fuzzy clustering algorithm. The results of this system generally correspond well to ground truth, both on a per slice basis and more importantly in tracking total tumor volume during treatment over time.

Clark, Matthew C.; Hall, Lawrence O.; Goldgof, Dmitry B.; Velthuizen, Robert P.; Murtaugh, F. R.; Silbiger, Martin L.

1998-06-01

129

Market Segmentation Analysis of Preferences for GM Derived Animal Foods in the UK  

Microsoft Academic Search

This paper undertakes a detailed market segmentation analysis of the demand for GM derived animal foods in the UK with the aim of illustrating how this analysis can provide distinct information that can assists in evaluating the welfare impacts of proposed changes to the EU's GM labelling policy. The specific modelling approach employed was the latent segment (LS) model which

Andreas Kontoleon; Mitsuyasu Yabe

2006-01-01

130

Fuzzy versus hard hidden Markov chains segmentation for volume determination and quantitation in noisy PET images  

Microsoft Academic Search

Accurate volume contouring in PET is crucial for quantitation in numerous oncology applications. The objective of our study was to compare the performance of two algorithms for automatic lesion volume delineation that permit noise modelling and have not previously been applied to PET data; namely the Hidden Markov Chains (HMC) model and a novel version: Fuzzy HMC. Both models take

Mathieu Hatt; Nicolas Boussion; Frederic Lamare; Christophe Collet; Fabien Salzenstein; Christian Roux; Yves Bizais; Catherine Cheze-le Rest; Dimitris Visvikis

2006-01-01

131

Automated detection, 3D segmentation and analysis of high resolution spine MR images using statistical shape models  

NASA Astrophysics Data System (ADS)

Recent advances in high resolution magnetic resonance (MR) imaging of the spine provide a basis for the automated assessment of intervertebral disc (IVD) and vertebral body (VB) anatomy. High resolution three-dimensional (3D) morphological information contained in these images may be useful for early detection and monitoring of common spine disorders, such as disc degeneration. This work proposes an automated approach to extract the 3D segmentations of lumbar and thoracic IVDs and VBs from MR images using statistical shape analysis and registration of grey level intensity profiles. The algorithm was validated on a dataset of volumetric scans of the thoracolumbar spine of asymptomatic volunteers obtained on a 3T scanner using the relatively new 3D T2-weighted SPACE pulse sequence. Manual segmentations and expert radiological findings of early signs of disc degeneration were used in the validation. There was good agreement between manual and automated segmentation of the IVD and VB volumes with the mean Dice scores of 0.89 ± 0.04 and 0.91 ± 0.02 and mean absolute surface distances of 0.55 ± 0.18 mm and 0.67 ± 0.17 mm respectively. The method compares favourably to existing 3D MR segmentation techniques for VBs. This is the first time IVDs have been automatically segmented from 3D volumetric scans and shape parameters obtained were used in preliminary analyses to accurately classify (100% sensitivity, 98.3% specificity) disc abnormalities associated with early degenerative changes.

Neubert, A.; Fripp, J.; Engstrom, C.; Schwarz, R.; Lauer, L.; Salvado, O.; Crozier, S.

2012-12-01

132

Automated detection, 3D segmentation and analysis of high resolution spine MR images using statistical shape models.  

PubMed

Recent advances in high resolution magnetic resonance (MR) imaging of the spine provide a basis for the automated assessment of intervertebral disc (IVD) and vertebral body (VB) anatomy. High resolution three-dimensional (3D) morphological information contained in these images may be useful for early detection and monitoring of common spine disorders, such as disc degeneration. This work proposes an automated approach to extract the 3D segmentations of lumbar and thoracic IVDs and VBs from MR images using statistical shape analysis and registration of grey level intensity profiles. The algorithm was validated on a dataset of volumetric scans of the thoracolumbar spine of asymptomatic volunteers obtained on a 3T scanner using the relatively new 3D T2-weighted SPACE pulse sequence. Manual segmentations and expert radiological findings of early signs of disc degeneration were used in the validation. There was good agreement between manual and automated segmentation of the IVD and VB volumes with the mean Dice scores of 0.89 ± 0.04 and 0.91 ± 0.02 and mean absolute surface distances of 0.55 ± 0.18 mm and 0.67 ± 0.17 mm respectively. The method compares favourably to existing 3D MR segmentation techniques for VBs. This is the first time IVDs have been automatically segmented from 3D volumetric scans and shape parameters obtained were used in preliminary analyses to accurately classify (100% sensitivity, 98.3% specificity) disc abnormalities associated with early degenerative changes. PMID:23201861

Neubert, A; Fripp, J; Engstrom, C; Schwarz, R; Lauer, L; Salvado, O; Crozier, S

2012-11-30

133

Analysis of segmental phosphate absorption in intact rats. A compartmental analysis approach.  

PubMed Central

Available information supports the dominance of the proximal intestine in inorganic phosphate (Pi) absorption. However, there is no strategy for analyzing segmental Pi absorption from a spontaneously propelled meal in an intact animal. We propose a solution using compartmental analysis. After intragastric administration of a 32P-labeled Pi liquid meal containing a nonabsorbable marker, [14C]polyethylene glycol (PEG), rats were killed at 2, 10, 20, 30, 60, 120, and 240 min. The gastrointestinal tract was removed and divided into seven segments, from which 32P and [14C]PEG were recovered. Data was expressed as a percentage of the dose fed, i.e., (32P[in segment] divided by 32P[fed]) and [14C]PEG[in segment] divided by [14C]PEG[fed]), respectively. A compartmental model was constructed and the rate constants for intersegmental transit and segmental absorption were estimated. The "goodness of fit" between the simulated model and the actual data indicates the estimated rate constants reflect in vivo events. The duodenum, with the highest transit and absorption rates, accounted for a third of the total absorption. However, the terminal ileum, with a lower absorption rate but a longer transit time, absorbed an equal amount of Pi. This approach allows the analysis of the mechanism and the regulation of Pi absorption under more authentic in vivo conditions. Images

Kayne, L H; D'Argenio, D Z; Meyer, J H; Hu, M S; Jamgotchian, N; Lee, D B

1993-01-01

134

Infant Word Segmentation and Childhood Vocabulary Development: A Longitudinal Analysis  

PubMed Central

Infants begin to segment novel words from speech by 7.5 months, demonstrating an ability to track, encode and retrieve words in the context of larger units. Although it is presumed that word recognition at this stage is a prerequisite to constructing a vocabulary, the continuity between these stages of development has not yet been empirically demonstrated. The goal of the present study is to investigate whether infant word segmentation skills are indeed related to later lexical development. Two word segmentation tasks, varying in complexity, were administered in infancy and related to childhood outcome measures. Outcome measures consisted of age-normed productive vocabulary percentiles and a measure of cognitive development. Results demonstrated a strong degree of association between infant word segmentation abilities at 7 months and productive vocabulary size at 24 months. In addition, outcome groups, as defined by median vocabulary size and growth trajectories at 24 months, showed distinct word segmentation abilities as infants. These findings provide the first prospective evidence supporting the predictive validity of infant word segmentation tasks and suggest that they are indeed associated with mature word knowledge.

Singh, Leher; Reznick, J. Steven; Xuehua, Liang

2012-01-01

135

Volume and Shape in Feature Space on Adaptive FCM in MRI Segmentation  

Microsoft Academic Search

Intensity non-uniformity (bias field) correction, contextual constraints over spatial intensity distribution and non-spherical\\u000a cluster’s shape in the feature space are incorporated into the fuzzy c-means (FCM) for segmentation of three-dimensional multi-spectral\\u000a MR images. The bias field is modeled by a linear combination of smooth polynomial basis functions for fast computation in\\u000a the clustering iterations. Regularization terms for the neighborhood continuity

Renjie He; Balasrinivasa Rao Sajja; Sushmita Datta; Ponnada A. Narayana

2008-01-01

136

Volume and shape in feature space on adaptive FCM in MRI segmentation  

PubMed Central

Intensity non-uniformity (bias field) correction, contextual constraints over spatial intensity distribution and non-spherical cluster's shape in the feature space are incorporated into the fuzzy c-means (FCM) for segmentation of three-dimensional multi-spectral MR images. The bias field is modeled by a linear combination of smooth polynomial basis functions for fast computation in the clustering iterations. Regularization terms for the neighborhood continuity of either intensity or membership are added into the FCM cost functions. Since the feature space is not isotropic, distance measures, other than the Euclidean distance, are used to account for the shape and volumetric effects of clusters in the feature space. The performance of segmentation is improved by combining the adaptive FCM scheme with the criteria used in Gustafson-Kessel (G-K) and Gath-Geva (G-G) algorithms through the inclusion of the cluster scatter measure. The performance of this integrated approach is quantitatively evaluated on normal MR brain images using the similarity measures. The improvement in the quality of segmentation obtained with our method is also demonstrated by comparing our results with those produced by FSL (FMRIB Software Library), a software package that is commonly used for tissue classification.

He, Renjie; Sajja, Balasrinivasa Rao; Datta, Sushmita; Narayana, Ponnada A.

2009-01-01

137

Atlas-Based Segmentation Improves Consistency and Decreases Time Required for Contouring Postoperative Endometrial Cancer Nodal Volumes  

SciTech Connect

Purpose: Accurate target delineation of the nodal volumes is essential for three-dimensional conformal and intensity-modulated radiotherapy planning for endometrial cancer adjuvant therapy. We hypothesized that atlas-based segmentation ('autocontouring') would lead to time savings and more consistent contours among physicians. Methods and Materials: A reference anatomy atlas was constructed using the data from 15 postoperative endometrial cancer patients by contouring the pelvic nodal clinical target volume on the simulation computed tomography scan according to the Radiation Therapy Oncology Group 0418 trial using commercially available software. On the simulation computed tomography scans from 10 additional endometrial cancer patients, the nodal clinical target volume autocontours were generated. Three radiation oncologists corrected the autocontours and delineated the manual nodal contours under timed conditions while unaware of the other contours. The time difference was determined, and the overlap of the contours was calculated using Dice's coefficient. Results: For all physicians, manual contouring of the pelvic nodal target volumes and editing the autocontours required a mean {+-} standard deviation of 32 {+-} 9 vs. 23 {+-} 7 minutes, respectively (p = .000001), a 26% time savings. For each physician, the time required to delineate the manual contours vs. correcting the autocontours was 30 {+-} 3 vs. 21 {+-} 5 min (p = .003), 39 {+-} 12 vs. 30 {+-} 5 min (p = .055), and 29 {+-} 5 vs. 20 {+-} 5 min (p = .0002). The mean overlap increased from manual contouring (0.77) to correcting the autocontours (0.79; p = .038). Conclusion: The results of our study have shown that autocontouring leads to increased consistency and time savings when contouring the nodal target volumes for adjuvant treatment of endometrial cancer, although the autocontours still required careful editing to ensure that the lymph nodes at risk of recurrence are properly included in the target volume.

Young, Amy V. [Department of Radiation Oncology, Beth Israel Medical Center, New York, NY (Israel); Department of Radiation Oncology, St. Luke's-Roosevelt Hospital, New York, NY (United States); Wortham, Angela [Department of Radiation Oncology, State University of New York Health Science Center of Brooklyn, Brooklyn, NY (United States); Wernick, Iddo; Evans, Andrew [Department of Radiation Oncology, St. Luke's-Roosevelt Hospital, New York, NY (United States); Ennis, Ronald D., E-mail: REnnis@chpnet.or [Department of Radiation Oncology, St. Luke's-Roosevelt Hospital, New York, NY (United States)

2011-03-01

138

Adolescents and alcohol: an explorative audience segmentation analysis  

PubMed Central

Background So far, audience segmentation of adolescents with respect to alcohol has been carried out mainly on the basis of socio-demographic characteristics. In this study we examined whether it is possible to segment adolescents according to their values and attitudes towards alcohol to use as guidance for prevention programmes. Methods A random sample of 7,000 adolescents aged 12 to 18 was drawn from the Municipal Basic Administration (MBA) of 29 Local Authorities in the province North-Brabant in the Netherlands. By means of an online questionnaire data were gathered on values and attitudes towards alcohol, alcohol consumption and socio-demographic characteristics. Results We were able to distinguish a total of five segments on the basis of five attitude factors. Moreover, the five segments also differed in drinking behavior independently of socio-demographic variables. Conclusions Our investigation was a first step in the search for possibilities of segmenting by factors other than socio-demographic characteristics. Further research is necessary in order to understand these results for alcohol prevention policy in concrete terms.

2012-01-01

139

Prioritization of brain MRI volumes using medical image perception model and tumor region segmentation.  

PubMed

The objective of the present study is to explore prioritization methods in diagnostic imaging modalities to automatically determine the contents of medical images. In this paper, we propose an efficient prioritization of brain MRI. First, the visual perception of the radiologists is adapted to identify salient regions. Then this saliency information is used as an automatic label for accurate segmentation of brain lesion to determine the scientific value of that image. The qualitative and quantitative results prove that the rankings generated by the proposed method are closer to the rankings created by radiologists. PMID:24034739

Mehmood, Irfan; Ejaz, Naveed; Sajjad, Muhammad; Baik, Sung Wook

2013-07-10

140

Neurological complications in segmental spinal instrumentation: analysis of 750 patients.  

PubMed

The authors report on neurological damage caused by the use of sublaminar segmental fixation in the correction of vertebral deformities. Three groups were reviewed: 600 patients instrumented with Harrington rods and segmental wiring, 50 patients treated with the Hartshill system and 100 patients instrumented with Luque bars. All of the patients were operated on using sublaminar wiring fixation. We report two transitory neurological complications among the 600 patients with Harrington rod instrumentation and segmental wiring, two permanent neurological deficits among the 50 cases treated with the Hartshill system and none among the 100 patients instrumented using Luque bars. The purpose of this study is to analyse the causes of these neurological complications, which occurred late in all four of the cases described. PMID:8831117

Cervellati, S; Bettini, N; Bianco, T; Parisini, P

1996-01-01

141

Robust Fuzzy C-Mean algorithm for Segmentation and analysis of Cytological images  

Microsoft Academic Search

In this paper, we are proposing a method for segmentation of PAP (Papinocolaou) smear images using Fuzzy C-Mean Algorithm (FCM) and analysis of the segmented images based on shape and size criteria. The traditional FCM algorithm used in the present study is modified by replacing the Euclidean distance metric by Mahalanobis distance metric. Further, the computation of the cluster center

C. K. Nath; Jyotismita Talukdar; P. H. Talukdar

2012-01-01

142

Quantitative Coronary Analysis Medical Image Processing Improved by Combining Wavelet Edge Detection and Segmentation  

Microsoft Academic Search

The quantitative coronary analysis (QCA) is a useful method for physicians to diagnose heart artery stenosis. So the precision of coronary angiography image quality is very definite important. In this study we present a precision 2-D image processing method that combines gradient segmentation and region segmentation approaches with an entropy maximization procedure. This method allows us to utilize all available

Tsair-Fwu Lee; Chang-Yu Lee; Pei-Ju Chao; Chieh Lee; Chang-Yu Wang; Chun-Hsiung Fang

2009-01-01

143

Human body image segmentation based on wavelet analysis and active contour models  

Microsoft Academic Search

GVF Snake model is used widely in computer vision and image segmentation. However, there are problems in convergence processing to boundaries of human body image because of noise. This paper presents a new segmentation algorithm to human body image. First, rough edge is got by multi-scale algorithm of wavelet analysis, and then thinning method based on mathematical morphology is adopted

Jin-Yong Cheng; Yi-Hui Liu

2007-01-01

144

Association of mean platelet volume and pre- and postinterventional flow with infarct-related artery in ST-segment elevation myocardial infarction.  

PubMed

Platelets play a role in the pathogenesis of ST-segment elevation myocardial infarction (STEMI). We assessed the relationship between mean platelet volume (MPV) on admission and pre- and postinterventional flow with the infarct-related artery (IRA) in patients with STEMI. We prospectively included 840 patients with STEMI who underwent primary percutaneous coronary intervention (PCI). The patients were divided into 3 groups according to MPV tertiles. Pre- and post-PCI Thrombolysis In Myocardial Infarction (TIMI) flow grade was determined. Initial TIMI flow grade 3 was accepted as patent IRA. After the primary PCI, normal flow was defined as post-PCI TIMI flow 3. When the MPV was increased, the incidence of pre-PCI patent IRA (P = .004) and post-PCI normal TIMI flow (P < .001) was significantly decreased. Multivariate analysis showed that MPV was independently associated with post-PCI TIMI flow grade. PMID:22887730

Elbasan, Zafer; Gür, Mustafa; Sahin, Durmu? Yildiray; Kuloglu, Osman; Icen, Yahya Kemal; Turkoglu, Caner; Ozkan, Bugra; Uysal, Onur Kadir; Kalkan, Gulhan Yuksel; Cayli, Murat

2012-08-09

145

Three-dimensional visualization of the craniofacial patient: volume segmentation, data integration and animation.  

PubMed

The research goal at the Craniofacial Virtual Reality Laboratory of the School of Dentistry in conjunction with the Integrated Media Systems Center, School of Engineering, University of Southern California, is to develop computer methods to accurately visualize patients in three dimensions using advanced imaging and data acquisition devices such as cone-beam computerized tomography (CT) and mandibular motion capture. Data from these devices were integrated for three-dimensional (3D) patient-specific visualization, modeling and animation. Generic methods are in development that can be used with common CT image format (DICOM), mesh format (STL) and motion data (3D position over time). This paper presents preliminary descriptive studies on: 1) segmentation of the lower and upper jaws with two types of CT data--(a) traditional whole head CT data and (b) the new dental Newtom CT; 2) manual integration of accurate 3D tooth crowns with the segmented lower jaw 3D model; 3) realistic patient-specific 3D animation of the lower jaw. PMID:14606537

Enciso, R; Memon, A; Mah, J

2003-01-01

146

Partial Volume Estimation of Brain Cortex from MRI Using Topology-Corrected Segmentation  

Microsoft Academic Search

In magnetic resonance imaging (MRI), accuracy of brain structures quantification may be affected by the partial volume (PV) effect. PV is due to the limited spatial resolution of MRI compared to the size of anatomical structures. When considering the cortex, measurements can be even more difficult as it spans only a few voxels. In tight sulci areas, where the two

Andrea Rueda; Oscar Acosta; Pierrick Bourgeat; Jurgen Fripp; Erik Bonner; Nicholas Dowson; Michel Couprie; Eduardo Romero; Olivier Salvado

2009-01-01

147

Volumetric analysis of liver segments in 155 living donors  

Microsoft Academic Search

Right-lobe graft has been used most frequently for living donor liver transplantation in adult patients; however, some donors cannot donate their right lobe (according to the Healey and Scroy's terminology) because the remaining residual liver would be too small. A recent study suggested the possibility of right posterior segment graft in these donors. The purpose of this study was to

Surasak Leelaudomlipi; Yasuhiko Sugawara; Junichi Kaneko; Yuichi Matsui; Takao Ohkubo; Masatoshi Makuuchi

2002-01-01

148

Applications of Recursive Segmentation to the Analysis of DNA Sequences  

Microsoft Academic Search

Recursive segmentation is a procedure that partitions a DNA sequence into domains with a homogeneous composition of the four nucleotides A, C, G and T. This procedure can also be applied to any sequence converted from a DNA sequence, such as to a binary strong(G + C)\\/weak(A+ T) sequence, to a binary sequence indicating the presence or absence of the

Wentian Li; Pedro Bernaola-galván; Fatameh Haghighi; Ivo Grosse

2002-01-01

149

Segmentation Analysis of the Volunteering Preferences of University Students  

Microsoft Academic Search

The purpose of this article is to explore how universities can increase volunteering among their students. To accomplish this objective, conjoint anlaysis was undertaken to determine the different underlying needs and preferences that drive the volunteering behavior of students. From this data, four need?based segments are identified and discussed. Strategies are then formulated to meet the needs and preferences of

Michael S. Garver; Richard L. Divine; Samuel A. Spralls

2009-01-01

150

Infant Word Segmentation and Childhood Vocabulary Development: A Longitudinal Analysis  

ERIC Educational Resources Information Center

|Infants begin to segment novel words from speech by 7.5 months, demonstrating an ability to track, encode and retrieve words in the context of larger units. Although it is presumed that word recognition at this stage is a prerequisite to constructing a vocabulary, the continuity between these stages of development has not yet been empirically…

Singh, Leher; Reznick, J. Steven; Xuehua, Liang

2012-01-01

151

Analysis of segmental kinetic energy in cricket bowling  

Microsoft Academic Search

Fast bowling in cricket is an athletic motion requiring the coordination of multiple body segments in order to release a ball at high speed. The application of the kinetic link principle to bowling proposes that the optimal coordination of movement actuation follows a proximal to distal sequence, allowing the systematic and progressive transfer of angular momentum from the larger, heavier

René E. D. Ferdinands

2011-01-01

152

Multilevel segmentation and analysis of facsimile images for document classification  

Microsoft Academic Search

Automatic processing of facsimile images which could classify and sort incoming transmissions and route them accordingly is a necessary component for an office automation system. A multilevel segmentation and classification system is presented. The first level indicates the major `visual' groupings of the information on the page and the second level explicitly identifies the number and type of internal elements.

Sally L. Wood; April Lee; Phillip L. Kelly

1991-01-01

153

A Model for Segmentation and Analysis of Noisy Images  

Microsoft Academic Search

This article proposes a statistical model for image generation that provides automatic segmentation of images into intensity-differentiated regions and facilitates the quantitative assessment of uncertainty associated with identified image features. The model is specified hierarchically within the Bayesian paradigm. At the lowest level in the hierarchy, a Gibbs distribution is used to specify a probability distribution on the space of

Valen E. Johnson

1994-01-01

154

Body volume changes during simulated microgravity: auditory changes, segmental fluid redistribution, and regional hemodynamics.  

PubMed

Space adaptation syndrome (SAS), manifested by cephalad fluid shifts, spacial disorientation, nausea, and vomiting, is of varied expression and uncertain etiology. One theory is that fluid shift to the upper body alters the function of the vestibular apparatus to create an entity similar to Meniere's disease. Since clinical vestibular dysfunction syndromes are mirrored by altered cochlear function, this experiment was undertaken to study the relation between fluid redistribution and the auditory effects of initial antiorthostatic bed rest. Manual and bone audiometry, impedance tympanometry, and brain-stem evoked potentials were used to monitor auditory changes prior to, during, and following short term exposure to -6 degrees head down tilt. Impedance plethysmography was performed to assess the segmental and intracranial fluid redistribution and hemodynamic changes during short-term head down tilt simulated microgravity. Even though significant cephalad fluid shift produced marked intracranial congestion and the subjects exhibited SAS symptoms, no clinically significant changes in the auditory system could be detected. PMID:8214826

Montgomery, L D; Parmet, A J; Booher, C R

155

Multi-rigid image segmentation and registration for the analysis of joint motion from three-dimensional magnetic resonance imaging.  

PubMed

We report an image segmentation and registration method for studying joint morphology and kinematics from in vivo magnetic resonance imaging (MRI) scans and its application to the analysis of foot and ankle joint motion. Using an MRI-compatible positioning device, a foot was scanned in a single neutral and seven other positions ranging from maximum plantar flexion, inversion, and internal rotation to maximum dorsiflexion, eversion, and external rotation. A segmentation method combining graph cuts and level set was developed. In the subsequent registration step, a separate rigid body transformation for each bone was obtained by registering the neutral position dataset to each of the other ones, which produced an accurate description of the motion between them. The segmentation algorithm allowed a user to interactively delineate 14 foot bones in the neutral position volume in less than 30 min total (user and computer processing unit [CPU]) time. Registration to the seven other positions took approximately 10 additional minutes of user time and 5.25 h of CPU time. For validation, our results were compared with those obtained from 3DViewnix, a semiautomatic segmentation program. We achieved excellent agreement, with volume overlap ratios greater than 88% for all bones excluding the intermediate cuneiform and the lesser metatarsals. For the registration of the neutral scan to the seven other positions, the average overlap ratio is 94.25%, while the minimum overlap ratio is 89.49% for the tibia between the neutral position and position 1, which might be due to different fields of view (FOV). To process a single foot in eight positions, our tool requires only minimal user interaction time (less than 30 min total), a level of improvement that has the potential to make joint motion analysis from MRI practical in research and clinical applications. PMID:22070330

Hu, Yangqiu; Ledoux, William R; Fassbind, Michael; Rohr, Eric S; Sangeorzan, Bruce J; Haynor, David

2011-10-01

156

Automated segmentation refinement of small lung nodules in CT scans by local shape analysis.  

PubMed

One of the most important problems in the segmentation of lung nodules in CT imaging arises from possible attachments occurring between nodules and other lung structures, such as vessels or pleura. In this report, we address the problem of vessels attachments by proposing an automated correction method applied to an initial rough segmentation of the lung nodule. The method is based on a local shape analysis of the initial segmentation making use of 3-D geodesic distance map representations. The correction method has the advantage that it locally refines the nodule segmentation along recognized vessel attachments only, without modifying the nodule boundary elsewhere. The method was tested using a simple initial rough segmentation, obtained by a fixed image thresholding. The validation of the complete segmentation algorithm was carried out on small lung nodules, identified in the ITALUNG screening trial and on small nodules of the lung image database consortium (LIDC) dataset. In fully automated mode, 217/256 (84.8%) lung nodules of ITALUNG and 139/157 (88.5%) individual marks of lung nodules of LIDC were correctly outlined and an excellent reproducibility was also observed. By using an additional interactive mode, based on a controlled manual interaction, 233/256 (91.0%) lung nodules of ITALUNG and 144/157 (91.7%) individual marks of lung nodules of LIDC were overall correctly segmented. The proposed correction method could also be usefully applied to any existent nodule segmentation algorithm for improving the segmentation quality of juxta-vascular nodules. PMID:21914567

Diciotti, Stefano; Lombardo, Simone; Falchini, Massimo; Picozzi, Giulia; Mascalchi, Mario

2011-09-12

157

Cost - Benefit Analysis for Inland Navigation Inprovements. Volume 3.  

National Technical Information Service (NTIS)

Research is directed towards improvement in procedures for the estimation of that portion of inland waterway transportation benefits which contribute to national income. The report is in three volumes. In the third volume, an analysis of regulatory policy...

J. P. Stucker L. N. Moses L. V. Lave M. V. Beythe W. B. Allen

1970-01-01

158

Segmentation and Structure Analysis for Real-Time Video Target Tracking.  

National Technical Information Service (NTIS)

Processing techniques for image segmentation and structure analysis were investigated at White Sands Missile Range (WSMR) during the period May through August 1977. An image processing facility was established at WSMR and used to develop and evaluate imag...

K. Fukunaga A. L. Gilbert M. K. Giles O. R. Mitchell R. D. Short

1977-01-01

159

Optimal Sparse Segment Identification with Application in Copy Number Variation Analysis  

PubMed Central

Motivated by DNA copy number variation (CNV) analysis based on high-density single nucleotide polymorphism (SNP) data, we consider the problem of detecting and identifying sparse short segments in a long one-dimensional sequence of data with additive Gaussian white noise, where the number, length and location of the segments are unknown. We present a statistical characterization of the identifiable region of a segment where it is possible to reliably separate the segment from noise. An efficient likelihood ratio selection (LRS) procedure for identifying the segments is developed, and the asymptotic optimality of this method is presented in the sense that the LRS can separate the signal segments from the noise as long as the signal segments are in the identifiable regions. The proposed method is demonstrated with simulations and analysis of a real data set on identification of copy number variants based on high-density SNP data. The results show that the LRS procedure can yield greater gain in power for detecting the true segments than some standard signal identification methods.

Jeng, X. Jessie; Cai, T. Tony; Li, Hongzhe

2012-01-01

160

Segmented regression analysis of interrupted time series studies in medication use research.  

PubMed

Interrupted time series design is the strongest, quasi-experimental approach for evaluating longitudinal effects of interventions. Segmented regression analysis is a powerful statistical method for estimating intervention effects in interrupted time series studies. In this paper, we show how segmented regression analysis can be used to evaluate policy and educational interventions intended to improve the quality of medication use and/or contain costs. PMID:12174032

Wagner, A K; Soumerai, S B; Zhang, F; Ross-Degnan, D

2002-08-01

161

Fire flame detection using color segmentation and space-time analysis  

Microsoft Academic Search

This paper presents a fire flame detection using CCTV cameras based on image processing. The scheme relies on color segmentation and space-time analysis. The segmentation is performed to extract fire-like-color regions in an image. Many methods are benchmarked against each other to find the best for practical CCTV camera. After that, the space-time analysis is used to recognized fire behavior.

Miti Ruchanurucks; Praphin Saengngoen; Theeraphat Sajjawiso

2011-01-01

162

Extended fractal analysis for texture classification and segmentation.  

PubMed

The Hurst parameter for two-dimensional (2-D) fractional Brownian motion (fBm) provides a single number that completely characterizes isotropic textured surfaces whose roughness is scale-invariant. Extended self-similar (ESS) processes were previously introduced in order to provide a generalization of fBm. These new processes are described by a number of multiscale Hurst parameters. In contrast to the single Hurst parameter, the extended parameters are able to characterize a greater variety of natural textures where the roughness of these textures is not necessarily scale-invariant. In this work, we evaluate the effectiveness of multiscale Hurst parameters as features for texture classification and segmentation. For texture classification, the performance of the generalized Hurst features is compared to traditional Hurst and Gabor features. Our experiments show that classification accuracy for the generalized Hurst and Gabor features are comparable even though the generalized Hurst features lower the dimensionality by a factor of five. Next, the segmentation accuracy using generalized and standard Hurst features is evaluated on images of texture mosaics. For these experiments, the performance is evaluated with and without supplemental contrast and average grayscale features. Finally, we investigate the effectiveness of the Hurst features to segment real synthetic aperture radar (SAR) imagery. PMID:18267432

Kaplan, L M

1999-01-01

163

Diffractive imaging analysis of large-aperture segmented telescope based on partial Fourier transform  

NASA Astrophysics Data System (ADS)

Large-aperture segmented primary mirror will be widely used in next-generation space-based and ground-based telescopes. The effects of intersegment gaps, obstructions, position and figure errors of segments, which are all involved in the pupil plane, on the image quality metric should be analyzed using diffractive imaging theory. Traditional Fast Fourier Transform (FFT) method is very time-consuming and costs a lot of memory especially in dealing with large pupil-sampling matrix. A Partial Fourier Transform (PFT) method is first proposed to substantially speed up the computation and reduce memory usage for diffractive imaging analysis. Diffraction effects of a 6-meter segmented mirror including 18 hexagonal segments are simulated and analyzed using PFT method. The influence of intersegment gaps and position errors of segments on Strehl ratio is quantitatively analyzed by computing the Point Spread Function (PSF). By comparing simulation results with theoretical results, the correctness and feasibility of PFT method is confirmed.

Dong, Bing; Qin, Shun; Hu, Xinqi

2013-09-01

164

Proteomic Analysis of the Retina: Removal of RPE Alters Outer Segment Assembly and Retinal Protein Expression  

PubMed Central

The mechanisms that regulate the complex physiologic task of photoreceptor outer segment assembly remain an enigma. One limiting factor in revealing the mechanism(s) by which this process is modulated is that not all of the role players that participate in this process are known. The purpose of this study was to determine some of the retinal proteins that likely play a critical role in regulating photoreceptor outer segment assembly. To do so, we analyzed and compared the proteome map of tadpole Xenopus laevis retinal pigment epithelium (RPE)-supported retinas containing organized outer segments with that of RPE-deprived retinas containing disorganized outer segments. Solubilized proteins were labeled with CyDye fluors followed by multiplexed two-dimensional separation. The intensity of protein spots and comparison of proteome maps was performed using DeCyder software. Identification of differentially regulated proteins was determined using nanoLC-ESI-MS/MS analysis. We found a total of 27 protein spots, 21 of which were unique proteins, which were differentially expressed in retinas with disorganized outer segments. We predict that in the absence of the RPE, oxidative stress initiates an unfolded protein response. Subsequently, downregulation of several candidate Müller glial cell proteins may explain the inability of photoreceptors to properly fold their outer segment membranes. In this study we have used identification and bioinformatics assessment of proteins that are differentially expressed in retinas with disorganized outer segments as a first step in determining probable key molecules involved in regulating photoreceptor outer segment assembly.

Wang, XiaoFei; Nookala, Suba; Narayanan, Chidambarathanu; Giorgianni, Francesco; Beranova-Giorgianni, Sarka; McCollum, Gary; Gerling, Ivan; Penn, John S.; Jablonski, Monica M.

2008-01-01

165

Combined texture feature analysis of segmentation and classification of benign and malignant tumour CT slices.  

PubMed

A computer software system is designed for the segmentation and classification of benign from malignant tumour slices in brain computed tomography (CT) images. This paper presents a method to find and select both the dominant run length and co-occurrence texture features of region of interest (ROI) of the tumour region of each slice to be segmented by Fuzzy c means clustering (FCM) and evaluate the performance of support vector machine (SVM)-based classifiers in classifying benign and malignant tumour slices. Two hundred and six tumour confirmed CT slices are considered in this study. A total of 17 texture features are extracted by a feature extraction procedure, and six features are selected using Principal Component Analysis (PCA). This study constructed the SVM-based classifier with the selected features and by comparing the segmentation results with the experienced radiologist labelled ground truth (target). Quantitative analysis between ground truth and segmented tumour is presented in terms of segmentation accuracy, segmentation error and overlap similarity measures such as the Jaccard index. The classification performance of the SVM-based classifier with the same selected features is also evaluated using a 10-fold cross-validation method. The proposed system provides some newly found texture features have an important contribution in classifying benign and malignant tumour slices efficiently and accurately with less computational time. The experimental results showed that the proposed system is able to achieve the highest segmentation and classification accuracy effectiveness as measured by jaccard index and sensitivity and specificity. PMID:23094909

Padma, A; Sukanesh, R

2012-10-24

166

Comparative Genomic and Transcriptomic Analysis of Tandemly and Segmentally Duplicated Genes in Rice  

PubMed Central

Tandem and segmental duplications significantly contribute to gene family expansion and genome evolution. Genome-wide identification of tandem and segmental genes has been analyzed before in several plant genomes. However, comparative studies in functional bias, expression divergence and their roles in species domestication are still lacking. We have carried out a genome-wide identification and comparative analysis of tandem and segmental genes in the rice genome. A total of 3,646 and 3,633 pairs of tandem and segmental genes, respectively, were identified in the genome. They made up around 30% of total annotated rice genes (excluding transposon-coding genes). Both tandem and segmental duplicates showed different physical locations and exhibited a biased subset of functions. These two types of duplicated genes were also under different functional constrains as shown by nonsynonymous substitutions per site (Ka) and synonymous substitutions per site (Ks) analysis. They are also differently regulated depending on the tissues and abiotic and biotic stresses based on transcriptomics data. The expression divergence might be related to promoter differentiation and DNA methylation status after tandem or segmental duplications. Both tandem and segmental duplications differ in their contribution to genetic novelty but evidence suggests that they play their role in species domestication and genome evolution.

Jiang, Shu-Ye; Gonzalez, Jose M.; Ramachandran, Srinivasan

2013-01-01

167

Segmentation and analysis of emission-computed-tomography images  

Microsoft Academic Search

This paper describes a statistical model for reconstruction of emission computed tomography (ECT) images. A distinguishing feature of this model is that it is parameterized in terms of quantities of direct physiological significance, rather than only in terms of grey-level voxel values. Specifically, parameters representing regions, region means, and region volumes are included in the model formulation and are estimated

Valen E. Johnson; James E. Bowsher; Jiang Qian; Ronald J. Jaszczak

1992-01-01

168

CONSUMER RESPONSE TO GENETICALLY MODIFIED FOODS: MARKET SEGMENT ANALYSIS AND IMPLICATIONS FOR PRODUCERS AND POLICY MAKERS  

Microsoft Academic Search

Conjoint analysis is used to elicit consumer preferences for attributes of genetically modified foods. Market segments are identified based on a cluster analysis of respondents' preferences for brand, price, and GMO content. A logit analysis is used to analyze consumer characteristics associated with the acceptance of GMO foods. Those consumers who were most risk averse, most likely to believe that

Gregory A. Baker; Thomas A. Burnham

2001-01-01

169

Genetic and physical analysis of a single Festuca pratensis chromosome segment substitution in Lolium perenne  

Microsoft Academic Search

Molecular marker analysis and genomic in situ hybridisation (GISH) were used to examine the process of chromosome segment introgression in BC2 diploid hybrids (2n=2x=14) between Lolium perenne and Festuca pratensis. Two genotypes having what appeared to be the same, single, introgressed chromosome segment of F. pratensis in the L. perenne background were crossed with diploid L. perenne to produce a

I. P. Armstead; A. Bollard; W. G. Morgan; J. A. Harper; I. P. King; R. N. Jones; J. W. Forster; M. D. Hayward; H. M. Thomas

2001-01-01

170

An automatic algorithm for the segmentation and morphological analysis of microvessels in immunostained histological tumour sections.  

PubMed

A fully automatic segmentation and morphological analysis algorithm for the analysis of microvessels from CD31 immunostained histological tumour sections is presented. Development of the algorithm exploited the distinctive hues of stained vascular endothelial cells, cell nuclei and background, to provide the seeds for a 'region-growing' method for object segmentation in the 3D hue, saturation, value (HSV) colour model. The segmented objects, identified as microvessels by CD31 immunostaining, were post-processed with three morphological tasks: joining separate objects that were likely to belong to a single vessel, closing objects that had a narrow gap around their periphery, and splitting objects with multiple lumina into individual vessels. The automatic segmentation was validated against a hand-segmented set of 44 images from three different SW1222 human colorectal carcinomas xenografted into mice. 96.3 ± 0.9% of pixels were found to be correctly classified. Automated segmentation was carried out on a further 53 images from three histologically distinct mouse fibrosarcomas (MFs) for morphological comparison with the SW1222 tumours. Four morphometric measurements were calculated for each segmented vessel: vascular area (VA), ratio of lumen area to vascular area (lu/VA), eccentricity (e), and roundness (ro). In addition, the total vascular area relative to tumour tissue area (rVA) was calculated. lu/VA, e and ro were found to be significantly smaller in MF tumours than in SW1222 tumours (p < 0.05; unpaired t-test). The algorithm is available through the website http://www.caiman.org.uk where images can be uploaded, processed and sent back to users. The output from CAIMAN consists of the original image with boundaries of segmented vessels overlaid, the calculated parameters and a Matlab file, which contains the segmentation that the user can use to derive further results. PMID:21118252

Reyes-Aldasoro, C C; Williams, L J; Akerman, S; Kanthou, C; Tozer, G M

2010-11-18

171

Health lifestyles: audience segmentation analysis for public health interventions.  

PubMed

This article is concerned with the application of market segmentation techniques in order to improve the planning and implementation of public health education programs. Seven distinctive patterns of health attitudes, social influences, and behaviors are identified using cluster analytic techniques in a sample drawn from four central California cities, and are subjected to construct and predictive validation: The lifestyle clusters predict behaviors including seatbelt use, vitamin C use, and attention to health information. The clusters also predict self-reported improvements in health behavior as measured in a two-year follow-up survey, e.g., eating less salt and losing weight, and self-reported new moderate and new vigorous exercise. Implications of these lifestyle clusters for public health education and intervention planning, and the larger potential of lifestyle clustering techniques in public health efforts, are discussed. PMID:2055779

Slater, M D; Flora, J A

1991-01-01

172

Segmental Analysis of Carotid Arterial Strain Using Speckle-Tracking  

PubMed Central

Background Increased arterial stiffness has been shown to be associated with aging and cardiovascular risk factors. Speckle-tracking algorithms are being used to measure myocardial strain. We evaluated if speckle-tracking could be used to measure carotid arterial wall strain (CAS) reproducibly in healthy volunteers and then examined if CAS was lesser in individuals with diabetes. Methods Bilateral electrocardiography-gated ultrasound scans of the distal common carotid arteries [D-CCA] (3 cardiac cycles, 14 MHz linear probe, mean 78.7 [Standard deviation (SD) 8.9]) frames per second were performed twice (2–4 days apart) on 10 healthy volunteers to test repeatability. Differences in CAS between healthy (n=20) and diabetic subjects (n=21) were examined. Peak CAS was measured in each of 6 equal segments and averages of all segments (i.e., global average), of the 3 nearest the probe, and of the 3 farthest from the probe (i.e., far wall average) were obtained. Results Global CAS (intraclass correlation coefficient [ICC]=0.40) and far wall average (ICC=0.63) had the greatest test-retest reliability. The global and far wall averaged CAS were lower in diabetics (4.29% [Standard Error (SE) 0.27%]; 4.30% [SE 0.44%], respectively) than in controls (5.48% [SE 0.29%], p=0.001; 5.58% [SE 0.44%], p=0.003, respectively). This difference persisted after adjustment for age, gender, race, and hemodynamic parameters. Conclusions Speckle-tracking for measuring carotid arterial wall strain is feasible and modestly reliable. Diabetic subjects had a lower carotid arterial wall strain obtained with speckle-tracking when compared with healthy controls.

Yang, Eric Y.; Dokainish, Hisham; Virani, Salim S.; Misra, Arunima; Pritchett, Allison M.; Lakkis, Nasser; Brunner, Gerd; Bobek, Jaromir; McCulloch, Marti L.; Hartley, Craig J.; Ballantyne, Christie M.; Nagueh, Sherif F.; Nambi, Vijay

2011-01-01

173

Analysis of wear mechanism and influence factors of drum segment of hot rolling coiler  

NASA Astrophysics Data System (ADS)

Because the work environment of segment is complex, and the wear failures usually happen, the wear mechanism corresponding to the load is a key factor for the solution of this problem. At present, many researchers have investigated the failure of segment, but have not taken into account the compositive influences of matching and coiling process. To investigate the wear failure of the drum segment of the hot rolling coiler, the MMU-5G abrasion tester is applied to simulate the wear behavior under different temperatures, different loads and different stages, and the friction coefficients and wear rates are acquired. Scanning electron microscopy(SEM) is used to observe the micro-morphology of worn surface, X-ray energy dispersive spectroscopy(EDS) is used to analyze the chemical composition of worn surface, finally the wear mechanism of segment in working process is judged and the influence regulars of the environmental factors on the material wear behaviors are found. The test and analysis results show that under certain load, the wear of the segment changes into oxidation wear from abrasive wear step by step with the temperature increases, and the wear degree reduces; under certain temperature, the main wear mechanism of segment changes into spalling wear from abrasive wear with the load increases, and the wear degree slightly increases. The proposed research provides a theoretical foundation and a practical reference for optimizing the wear behavior and extending the working life of segment.

Zhang, Jian; Peng, Yan; Liu, Hongmin; Liu, Yunfei

2013-03-01

174

Design and validation of Segment - freely available software for cardiovascular image analysis  

PubMed Central

Background Commercially available software for cardiovascular image analysis often has limited functionality and frequently lacks the careful validation that is required for clinical studies. We have already implemented a cardiovascular image analysis software package and released it as freeware for the research community. However, it was distributed as a stand-alone application and other researchers could not extend it by writing their own custom image analysis algorithms. We believe that the work required to make a clinically applicable prototype can be reduced by making the software extensible, so that researchers can develop their own modules or improvements. Such an initiative might then serve as a bridge between image analysis research and cardiovascular research. The aim of this article is therefore to present the design and validation of a cardiovascular image analysis software package (Segment) and to announce its release in a source code format. Results Segment can be used for image analysis in magnetic resonance imaging (MRI), computed tomography (CT), single photon emission computed tomography (SPECT) and positron emission tomography (PET). Some of its main features include loading of DICOM images from all major scanner vendors, simultaneous display of multiple image stacks and plane intersections, automated segmentation of the left ventricle, quantification of MRI flow, tools for manual and general object segmentation, quantitative regional wall motion analysis, myocardial viability analysis and image fusion tools. Here we present an overview of the validation results and validation procedures for the functionality of the software. We describe a technique to ensure continued accuracy and validity of the software by implementing and using a test script that tests the functionality of the software and validates the output. The software has been made freely available for research purposes in a source code format on the project home page http://segment.heiberg.se. Conclusions Segment is a well-validated comprehensive software package for cardiovascular image analysis. It is freely available for research purposes provided that relevant original research publications related to the software are cited.

2010-01-01

175

Topology-corrected segmentation and local intensity estimates for improved partial volume classification of brain cortex in MRI.  

PubMed

In magnetic resonance imaging (MRI), accuracy and precision with which brain structures may be quantified are frequently affected by the partial volume (PV) effect. PV is due to the limited spatial resolution of MRI compared to the size of anatomical structures. Accurate classification of mixed voxels and correct estimation of the proportion of each pure tissue (fractional content) may help to increase the precision of cortical thickness estimation in regions where this measure is particularly difficult, such as deep sulci. The contribution of this work is twofold: on the one hand, we propose a new method to label voxels and compute tissue fractional content, integrating a mechanism for detecting sulci with topology preserving operators. On the other hand, we improve the computation of the fractional content of mixed voxels using local estimation of pure tissue intensity means. Accuracy and precision were assessed using simulated and real MR data and comparison with other existing approaches demonstrated the benefits of our method. Significant improvements in gray matter (GM) classification and cortical thickness estimation were brought by the topology correction. The fractional content root mean squared error diminished by 6.3% (p<0.01) on simulated data. The reproducibility error decreased by 8.8% (p<0.001) and the Jaccard similarity measure increased by 3.5% on real data. Furthermore, compared with manually guided expert segmentations, the similarity measure was improved by 12.0% (p<0.001). Thickness estimation with the proposed method showed a higher reproducibility compared with the measure performed after partial volume classification using other methods. PMID:20193712

Rueda, Andrea; Acosta, Oscar; Couprie, Michel; Bourgeat, Pierrick; Fripp, Jurgen; Dowson, Nicholas; Romero, Eduardo; Salvado, Olivier

2010-03-01

176

High-throughput microcoil NMR of compound libraries using zero-dispersion segmented flow analysis.  

PubMed

An automated system for loading samples into a microcoil NMR probe has been developed using segmented flow analysis. This approach enhanced 2-fold the throughput of the published direct injection and flow injection methods, improved sample utilization 3-fold, and was applicable to high-field NMR facilities with long transfer lines between the sample handler and NMR magnet. Sample volumes of 2 microL (10-30 mM, approximately 10 microg) were drawn from a 96-well microtiter plate by a sample handler, then pumped to a 0.5-microL microcoil NMR probe as a queue of closely spaced "plugs" separated by an immiscible fluorocarbon fluid. Individual sample plugs were detected by their NMR signal and automatically positioned for stopped-flow data acquisition. The sample in the NMR coil could be changed within 35 s by advancing the queue. The fluorocarbon liquid wetted the wall of the Teflon transfer line, preventing the DMSO samples from contacting the capillary wall and thus reducing sample losses to below 5% after passage through the 3-m transfer line. With a wash plug of solvent between samples, sample-to-sample carryover was <1%. Significantly, the samples did not disperse into the carrier liquid during loading or during acquisitions of several days for trace analysis. For automated high-throughput analysis using a 16-second acquisition time, spectra were recorded at a rate of 1.5 min/sample and total deuterated solvent consumption was <0.5 mL (1 US dollar) per 96-well plate. PMID:15638474

Kautz, Roger A; Goetzinger, Wolfgang K; Karger, Barry L

177

Automatic segmentation of the colon  

NASA Astrophysics Data System (ADS)

Virtual colonoscopy is a minimally invasive technique that enables detection of colorectal polyps and cancer. Normally, a patient's bowel is prepared with colonic lavage and gas insufflation prior to computed tomography (CT) scanning. An important step for 3D analysis of the image volume is segmentation of the colon. The high-contrast gas/tissue interface that exists in the colon lumen makes segmentation of the majority of the colon relatively easy; however, two factors inhibit automatic segmentation of the entire colon. First, the colon is not the only gas-filled organ in the data volume: lungs, small bowel, and stomach also meet this criteria. User-defined seed points placed in the colon lumen have previously been required to spatially isolate only the colon. Second, portions of the colon lumen may be obstructed by peristalsis, large masses, and/or residual feces. These complicating factors require increased user interaction during the segmentation process to isolate additional colon segments. To automate the segmentation of the colon, we have developed a method to locate seed points and segment the gas-filled lumen with no user supervision. We have also developed an automated approach to improve lumen segmentation by digitally removing residual contrast-enhanced fluid resulting from a new bowel preparation that liquefies and opacifies any residual feces.

Wyatt, Christopher L.; Ge, Yaorong; Vining, David J.

1999-05-01

178

Colour and texture segmentation using wavelet frame analysis, deterministic relaxation, and fast marching algorithms  

Microsoft Academic Search

Luminance, colour, and\\/or texture features may be used, either alone or in combination, for segmentation. In this paper luminance and colour classes are described using the corre- sponding empirical probability distributions. For texture analysis and characterisation a mul- tichannel scale\\/orientation decomposition is performed using wavelet frame analysis. Knowing only the number of the different classes of the image, regions of

Spyros Liapis; Eftychios Sifakis; Georgios Tziritas

2004-01-01

179

Modern Trends in Activation Analysis. Volumes 1 and 2.  

National Technical Information Service (NTIS)

A conference on modern trends in activation analysis was held at the National Bureau of Standards, October 7-11, 1968. These volumes contain the texts of five plenary lectures namely, applications of activation analysis, radiochemical separations, nuclear...

J. R. DeVoe P. D. LaFleur

1969-01-01

180

Automatic segmentation of solitary pulmonary nodules based on local intensity structure analysis and 3D neighborhood features in 3D chest CT images  

NASA Astrophysics Data System (ADS)

This paper presents a solitary pulmonary nodule (SPN) segmentation method based on local intensity structure analysis and neighborhood feature analysis in chest CT images. Automated segmentation of SPNs is desirable for a chest computer-aided detection/diagnosis (CAS) system since a SPN may indicate early stage of lung cancer. Due to the similar intensities of SPNs and other chest structures such as blood vessels, many false positives (FPs) are generated by nodule detection methods. To reduce such FPs, we introduce two features that analyze the relation between each segmented nodule candidate and it neighborhood region. The proposed method utilizes a blob-like structure enhancement (BSE) filter based on Hessian analysis to augment the blob-like structures as initial nodule candidates. Then a fine segmentation is performed to segment much more accurate region of each nodule candidate. FP reduction is mainly addressed by investigating two neighborhood features based on volume ratio and eigenvector of Hessian that are calculates from the neighborhood region of each nodule candidate. We evaluated the proposed method by using 40 chest CT images, include 20 standard-dose CT images that we randomly chosen from a local database and 20 low-dose CT images that were randomly chosen from a public database: LIDC. The experimental results revealed that the average TP rate of proposed method was 93.6% with 12.3 FPs/case.

Chen, Bin; Kitasaka, Takayuki; Honma, Hirotoshi; Takabatake, Hirotsugu; Mori, Masaki; Natori, Hiroshi; Mori, Kensaku

2012-02-01

181

Fire flame detection using color segmentation and space-time analysis  

NASA Astrophysics Data System (ADS)

This paper presents a fire flame detection using CCTV cameras based on image processing. The scheme relies on color segmentation and space-time analysis. The segmentation is performed to extract fire-like-color regions in an image. Many methods are benchmarked against each other to find the best for practical CCTV camera. After that, the space-time analysis is used to recognized fire behavior. A space-time window is generated from contour of the threshold image. Feature extraction is done in Fourier domain of the window. Neural network is used for behavior recognition. The system will be shown to be practical and robust.

Ruchanurucks, Miti; Saengngoen, Praphin; Sajjawiso, Theeraphat

2011-10-01

182

Clinical validation of atlas-based auto-segmentation of pelvic volumes and normal tissue in rectal tumors using auto-segmentation computed system.  

PubMed

Abstract Purpose. To evaluate in two different settings - clinical practice and education/training - the reliability, time efficiency and the ideal sequence of an atlas-based auto-segmentation system in pelvic delineation of locally advanced rectal cancer. Methods. Fourteen consecutive patients were selected between October and December 2011. The images of four were used as an atlas and 10 used for validation. Two independent operators participated: a Delineator to contour and a Reviewer to perform an independent check (IC). The CTV, pelvic subsites and organs at risk were contoured in four different sequences. These included A: manual; B: auto-segmentation; C: auto-segmentation + manual revision; and D: manual + auto-segmentation + manual revision. Contouring was performed by the Delineator using the same planning CT. All of them underwent an IC by a Reviewer. The time required for all the contours were recorded and overlapping evaluation was assessed using a Dice coefficient. Results. In the clinical practice setting there have been 13 minutes time saved between sequences A versus sequences B (from 38 to 25 minutes, p = 0.002), a mean Dice coefficient in favor of sequences A for CTV and all subsites (p = 0.0195). In the educational/training setting there have been 35.2 minutes time saved between sequences C and D 8 (from 73.1 min to 37.9 min, p = 0.002). Conclusion. The preliminary data suggest that the use of an atlas-based auto-contouring system may help improve efficiencies in contouring in the clinical practice setting and could have a tutorial role in the educational/training setting. PMID:23336255

Gambacorta, Maria Antonietta; Valentini, Chiara; Dinapoli, Nicola; Boldrini, Luca; Caria, Nicola; Barba, Maria Cristina; Mattiucci, Gian Carlo; Pasini, Danilo; Minsky, Bruce; Valentini, Vincenzo

2013-01-22

183

24 Hour ST Segment Analysis in Transient Left Ventricular Apical Ballooning  

PubMed Central

Objective The etiologic basis of transient left ventricular apical ballooning, a novel cardiac syndrome, is not clear. Among the proposed pathomechanisms is coronary vasospasm. Long-term ST segment analysis may detect vasospastic episodes but has not been reported. Methods 30 consecutive patients with transient left ventricular apical ballooning, left ventricular dysfunction and normal or near-normal coronary arteries were investigated. A 24-hour Holter ECG was obtained after emergency admission. ST segment analysis was performed automatically in 2 leads and confirmed by visual inspection. Criteria for an ischemic event were: 1. ST elevation or 2. horizontal or down-sloping ST segments ?1 min duration and ?100 µV J+80 point deviation corrected for baseline ST-deviation. Results Patients presented with ST segment elevation (n?=?19) and/or T wave inversion (n?=?20) on admission ECG. Ejection fraction was 50±12%. No transient ST elevations were observed during Holter ECG analysis. In 3 patients, 8 transient episodes of ST depression were recorded. Durations of episodes varied between 75s and 790s (mean 229s). Maximal ST deviation averaged ?191±71 µV. Ischemic burden was ?1 to ?22 mVs (mean ?8 mVs). 27 patients showed no ischemic events. Conclusions ST segment analysis of 24 h Holter recordings revealed minor ischemic events in only 10% of patients with transient left ventricular apical ballooning. Overall, ST segment changes were not indicative of recurrent coronary spasm playing a major role in the genesis of transient left ventricular apical ballooning.

Bode, Frank; Burgdorf, Christof; Schunkert, Heribert; Kurowski, Volkhard

2013-01-01

184

Automated segmentation and tracking for large-scale analysis of focal adhesion dynamics.  

PubMed

Cell adhesion, a process mediated by the formation of discrete structures known as focal adhesions (FAs), is pivotal to many biological events including cell motility. Much is known about the molecular composition of FAs, although our knowledge of the spatio-temporal recruitment and the relative occupancy of the individual components present in the FAs is still incomplete. To fill this gap, an essential prerequisite is a highly reliable procedure for the recognition, segmentation and tracking of FAs. Although manual segmentation and tracking may provide some advantages when done by an expert, its performance is usually hampered by subjective judgement and the long time required in analysing large data sets. Here, we developed a model-based segmentation and tracking algorithm that overcomes these problems. In addition, we developed a dedicated computational approach to correct segmentation errors that may arise from the analysis of poorly defined FAs. Thus, by achieving accurate and consistent FA segmentation and tracking, our work establishes the basis for a comprehensive analysis of FA dynamics under various experimental regimes and the future development of mathematical models that simulate FA behaviour. PMID:21118203

Würflinger, T; Gamper, I; Aach, T; Sechi, A S

2011-01-01

185

Dextrocardia--value of segmental analysis in its categorisation  

Microsoft Academic Search

Dextrocardia can be defined as a heart in the right chest with the major axis to the right. This definition, however, conveys no information regarding the chamber arrangements and internal anatomy of the heart. Of 40 patients satisfying this definition in the files of the Brompton Hospital, 33 had angiocardiographic data adequate for complete analysis in terms of connections, relations,

G Calcaterra; R H Anderson; K C Lau; E A Shinebourne

1979-01-01

186

Toward Real-Time Biopsy Image Analysis and Cell Segmentation  

Microsoft Academic Search

This Digital Signal Processing (DSP) study is aimed at real-time capture and analysis of pathological brain images to improve accuracy and efficiency. Simply analyzing cell density statistics and average cell nucleus diameters of a slide image is shown to be useful to determine the abnormality of brain sample. Numerous biopsy samples of various types obtained around the world daily are

Luis Hernández; Paula Gothreaux; Liwen Shih; Gerald Campbell

2006-01-01

187

Customer decision making in fashion retailing: a segmentation analysis  

Microsoft Academic Search

Research into store image, market positioning and store choice has mainly been carried out in supermarkets or department stores and only a limited amount in speciality retailing. This study uses conjoint analysis to examine the way consumers choose where to purchase menswear fashion clothing, based on their perception and trade-off of four attributes - price, quality, selection and staff -

Grete Birtwistle; Ian Clarke; Paul Freathy

1998-01-01

188

Intelligent approach for PET volume analysis  

Microsoft Academic Search

Tumour classification and quantification in positron emission tomography (PET) imaging at early stage of illness are important for radiotherapy planning, tumour diagnosis, and fast recovery. Analysing large medical volumes using traditional techniques requires a decent amount of time, and in some approaches poor accuracy is achieved. Artificial intelligence (AI) technologies can provide better accuracy and save decent amount of time.

Mhd Saeed Sharif; Abbes Amira; Habib Zaidi

2010-01-01

189

Making Prevention Pay. Appendix Volume II. Selected Analysis Papers.  

National Technical Information Service (NTIS)

These seven selected analysis papers were produced as background material for the Task Force's Draft Final Report, Making Prevention Pay (released 12/18/79). This Volume includes a Table of Contents and seven papers, organized as chapters of this volume. ...

1979-01-01

190

A new CAD mesh segmentation method, based on curvature tensor analysis  

Microsoft Academic Search

This paper presents a new and efficient algorithm for the decomposition of 3D arbitrary triangle meshes and particularly optimized triangulated CAD meshes. The algorithm is based on the curvature tensor field analysis and presents two distinct complementary steps: a region based segmentation, which is an improvement of that presented by Lavoue et al. (Lavoue G, Dupont F, Baskurt A. Constant

Guillaume Lavoué; Florent Dupont; Atilla Baskurt

2005-01-01

191

Segmented chirp Z-transform and multiple deep dip windows for electrical power system harmonic analysis  

Microsoft Academic Search

The combined use of the Segmented Chirp Z-Transform (SCZT) and of the Multiple Deep Dip (MDD) windows is proposed and applied to electrical power system harmonic analysis. The goal of increasing the resolvability of low magnitude non-harmonic tones close in frequency to higher magnitude harmonics and the detectability of very low magnitude high frequency harmonics is pursued. The SCZT allows

P. Daponte; D. Menniti; A. Testa

1996-01-01

192

Analysis of horizontally curved post-tensioned segmental concrete box girder bridges  

Microsoft Academic Search

This report presents the background and details of a numerical procedure developed specifically for the longitudinal analysis of curved segmentally erected prestressed concrete box girder bridges. It is based on a skew ended thin-wall beam element including the modes of warping and distorsion of the cross section. The cross section must consist of a single cell, may have overhangs, and

Rafael Manuel Rojas

1993-01-01

193

Segmental analysis of mercury in hair in 80 women of Nome, Alaska.  

National Technical Information Service (NTIS)

Eighty samples of hair from women of child-bearing age from Nome, Alaska, and seven control samples from women living in the Sequim, Washington, area were analyzed for mercury concentration by segmental analysis in an effort to determine whether seasonal ...

B. K. Lasorsa R. J. Citterman

1991-01-01

194

[Comparative analysis of internal repeating segments in proteins of species from the three kingdoms of life].  

PubMed

In 1970's, Ohno proposed that primordial proteins might evolve from periodic amplification of oligopeptides. Internal repeating segments in proteins may play important roles in functional evolution of proteins. In this study,a new method was designed to extract internal repeating segments from proteomes of 8 modern species belong to eukaryota, bacteria and archaea, respectively. The repeating patterns and the frequencies within proteomes of each kingdom were analyzed by matrix plot. Simple repeat segments were found in eukaryotic proteins with high frequencies,but were much lower in bacteria and none in archaea. Further analysis showed that, the biased usage of amino acids in the internal repeating segments was positively related to the frequencies of individual amino acids in the proteome of a given species. The correlation coefficient was up to 0.95 in prokaryota, with the eukaryota to be lower. The high frequency of simple repeat sequences in eukaryotic proteomes, as well as the disparate relationships of amino acid compositions between the internal repeating segments and their haboring eukaryotic proteomes imply that the fast evolution of simple repeat sequences could be one force that generates the high complexity of eukarytic proteomes. PMID:15931794

Chen, Hao; Zhu, Sheng; Chen, Liang-Biao

2005-03-01

195

Two-dimensional finite-element analysis of tapered segmented structures  

NASA Astrophysics Data System (ADS)

We present the results of the theoretical study and two-dimensional frequency domain finite-element simulation of tapered segmented waveguides. The application that we propose for this device is an adiabatically tapered and chirped PSW transmission, to eliminate higher order modes that can be propagated in a multimode semiconductor waveguide assuring mono mode propagation at 1.55?m. We demonstrate that by reducing the taper functions for the design of a segmented waveguide we can filter higher order modes at pump wavelength in WDM systems and at the same time low coupling losses between the continuous waveguide and the segmented waveguide. We obtained the cutoff wavelength as a function of the duty cycle of the segmented waveguide to show that we can, in fact, guide 1.55?m fundamental mode over a silicon-on-insulator platform using both, silica and SU-8 as substrate material. For the two-dimensional finite element analysis a new module over a commercial platform is proposed. Its contribution is the inclusion of the anisotropic perfectly matched layer that is more suitable for solving periodic segmented structures and other discontinuity problems.

Rubio Noriega, Ruth; Hernandez-Figueroa, Hugo

2013-03-01

196

New Software for Market Segmentation Analysis: A Chi-Square Interaction Detector. AIR 1983 Annual Forum Paper.  

ERIC Educational Resources Information Center

|The advantages and disadvantages of new software for market segmentation analysis are discussed, and the application of this new, chi-square based procedure (CHAID), is illustrated. A comparison is presented of an earlier, binary segmentation technique (THAID) and a multiple discriminant analysis. It is suggested that CHAID is superior to earlier…

Lay, Robert S.

197

Methodology for Flexible and Efficient Analysis of the Performance of Page Segmentation Algorithms  

Microsoft Academic Search

This paper presents part of a new DIA performance analysis framework aimed at Layout Analysis algorithm developers. A new region-representation scheme (an interval-based description of isothetic polygons) and a corresponding comparison approach are introduced. These enable fast and accurate geometric comparison of ground-truth with results of page segmentation, improving on current evaluation methods. Complex layouts are accurately described and Layout

Apostolos Antonacopoulos; A. Brough

1999-01-01

198

Market segmentation for multiple option healthcare delivery systems--an application of cluster analysis.  

PubMed

Healthcare providers of multiple option plans may be confronted with special market segmentation problems. This study demonstrates how cluster analysis may be used for discovering distinct patterns of preference for multiple option plans. The availability of metric, as opposed to categorical or ordinal, data provides the ability to use sophisticated analysis techniques which may be superior to frequency distributions and cross-tabulations in revealing preference patterns. PMID:10105775

Jarboe, G R; Gates, R H; McDaniel, C D

1990-01-01

199

The Multi-Purpose Camera: A New Anterior Eye Segment Analysis System  

Microsoft Academic Search

A new device for the analysis of the anterior eye segment was developed. With this device, a Scheimpflug slit image and a retroiUumination image can be taken separately using a CCD camera. The quality of the images obtained was satisfactory enough for analysis. The data obtained were stored and analyzed on an almost real-time level using an on-line computer. The

Kazuyuki Sasaki; Yasuo Sakamoto; Takashi Shibata; Yasufumi Emori

1990-01-01

200

Segmental increases in force application during colonoscope insertion: quantitative analysis using force monitoring technology  

PubMed Central

Background Colonoscopy is a frequently performed procedure that requires extensive training and a high skill level. Objective Quantification of forces applied to the external portion of the colonoscope insertion tube during the insertion phase of colonoscopy. Design Observational cohort study of 7 expert and 9 trainee endoscopists for analysis of colonic segment force application in 49 patients. Forces were measured by using the colonoscopy force monitor, which is a wireless, handheld device that attaches to the insertion tube of the colonoscope. Setting Academic gastroenterology training programs. Patients Patients undergoing routine screening or diagnostic colonoscopy with complete segment force recordings. Main Outcome Measurements Axial and radial force and examination time. Results Both axial and radial force increased significantly as the colonoscope was advanced from the rectum to the cecum. Analysis of variance demonstrated highly significant operator-independent differences between segments of the colon (zones) in all axial and radial forces except average torque. Expert and trainee endoscopists differed only in the magnitude of counterclockwise force, average push/pull force rate used, and examination time. Limitations Small study, observational design, effect of prototype device on insertion tube manipulation. Conclusion Axial and radial forces used to advance the colonoscope increase through the segments of the colon and are operator independent.

Korman, Louis Y.; Brandt, Lawrence J.; Metz, David C.; Haddad, Nadim G.; Benjamin, Stanley B.; Lazerow, Susan K.; Miller, Hannah L.; Greenwald, David A.; Desale, Sameer; Patel, Milind; Sarvazyan, Armen

2012-01-01

201

Information architecture. Volume 2, Part 1: Baseline analysis summary  

SciTech Connect

The Department of Energy (DOE) Information Architecture, Volume 2, Baseline Analysis, is a collaborative and logical next-step effort in the processes required to produce a Departmentwide information architecture. The baseline analysis serves a diverse audience of program management and technical personnel and provides an organized way to examine the Department`s existing or de facto information architecture. A companion document to Volume 1, The Foundations, it furnishes the rationale for establishing a Departmentwide information architecture. This volume, consisting of the Baseline Analysis Summary (part 1), Baseline Analysis (part 2), and Reference Data (part 3), is of interest to readers who wish to understand how the Department`s current information architecture technologies are employed. The analysis identifies how and where current technologies support business areas, programs, sites, and corporate systems.

NONE

1996-12-01

202

Segmental bioelectrical impedance analysis in children aged 8–12 y: 1. The assessment of whole-body composition  

Microsoft Academic Search

Objectives: To investigate the potential of segmental bioelectrical impedance analysis (BIA) for estimating whole-body composition in children.Design: Strengths of relationships were determined between indices of impedance or specific resistivities of body segments and reference four-component model (4-CM) assessments of body composition.Subjects: Eighteen boys and 19 girls aged 8–12 y.Measurements: Whole-body and segment BIA and anthropometry were used to calculate impedance

NJ Fuller; O Dewit; M Elia; JCK Wells

2002-01-01

203

Computer-aided measurement of liver volumes in CT by means of geodesic active contour segmentation coupled with level-set algorithms  

SciTech Connect

Purpose: Computerized liver extraction from hepatic CT images is challenging because the liver often abuts other organs of a similar density. The purpose of this study was to develop a computer-aided measurement of liver volumes in hepatic CT. Methods: The authors developed a computerized liver extraction scheme based on geodesic active contour segmentation coupled with level-set contour evolution. First, an anisotropic diffusion filter was applied to portal-venous-phase CT images for noise reduction while preserving the liver structure, followed by a scale-specific gradient magnitude filter to enhance the liver boundaries. Then, a nonlinear grayscale converter enhanced the contrast of the liver parenchyma. By using the liver-parenchyma-enhanced image as a speed function, a fast-marching level-set algorithm generated an initial contour that roughly estimated the liver shape. A geodesic active contour segmentation algorithm coupled with level-set contour evolution refined the initial contour to define the liver boundaries more precisely. The liver volume was then calculated using these refined boundaries. Hepatic CT scans of 15 prospective liver donors were obtained under a liver transplant protocol with a multidetector CT system. The liver volumes extracted by the computerized scheme were compared to those traced manually by a radiologist, used as ''gold standard.''Results: The mean liver volume obtained with our scheme was 1504 cc, whereas the mean gold standard manual volume was 1457 cc, resulting in a mean absolute difference of 105 cc (7.2%). The computer-estimated liver volumetrics agreed excellently with the gold-standard manual volumetrics (intraclass correlation coefficient was 0.95) with no statistically significant difference (F=0.77; p(F{<=}f)=0.32). The average accuracy, sensitivity, specificity, and percent volume error were 98.4%, 91.1%, 99.1%, and 7.2%, respectively. Computerized CT liver volumetry would require substantially less completion time (compared to an average of 39 min per case by manual segmentation). Conclusions: The computerized liver extraction scheme provides an efficient and accurate way of measuring liver volumes in CT.

Suzuki, Kenji; Kohlbrenner, Ryan; Epstein, Mark L.; Obajuluwa, Ademola M.; Xu Jianwu; Hori, Masatoshi [Department of Radiology, University of Chicago, 5841 South Maryland Avenue, Chicago, Illinois 60637 (United States)

2010-05-15

204

Recovery of Photoreceptor Outer Segment Length and Analysis of Membrane Assembly Rates in Regenerating Primate Photoreceptor Outer Segments  

Microsoft Academic Search

Purpose. Photoreceptor outer segments are in a dynamic state of membrane addition and disposal. This study was undertaken to determine how a standardized period of retinal detach- ment and varying periods of reattachment affect the renewal process. Methods. To investigate the effects that retinal detachment and reattachment may have on this process, the neural retina from 12 adult rhesus monkeys

Christopher J. Guerin; Geoffrey P. Lewis; Steven K. Fisher; Don H. Anderson

205

Breast volume measurement of 598 women using biostereometric analysis.  

PubMed

A study of the volumes of the right and left breasts of 598 subjects was undertaken using biostereometric analysis. This measurement uses close-range stereophotogrammetry to characterize the shape of the breast, and is noncontact, noninvasive, accurate, and rapid with respect to the subject involvement time. Using chi-square tests, volumes and volumetric differences between breast pairs were compared with handedness, perception of breast size by each subject, age, and menstrual status. No significant relationship was found between the handedness, age, or menstrual status of the subject and the breast volume. Several groups of subjects were accurate in their perception of breast size difference. Analysis did confirm the generally accepted clinical impression of left-breast volume dominance. These results are shown to be consistent with those of a previous study using 248 women. PMID:2729845

Loughry, C W; Sheffer, D B; Price, T E; Einsporn, R L; Bartfai, R G; Morek, W M; Meli, N M

1989-05-01

206

Analysis of the secondary structure of expansion segment 39 in ribosomes from fungi, plants and mammals.  

PubMed

The structure of expansion segment 39, ES39, in eukaryotic 23 S-like ribosomal RNA was analysed using a combination of chemical and enzymic reagents. Ribosomes were isolated from yeast, wheat, mouse, rat and rabbit, five organisms representing three different eukaryotic kingdoms. The isolated ribosomes were treated with structure-sensitive chemical and enzymic reagents and the modification patterns analysed by primer extension and gel electrophoresis on an ABI 377 automated DNA sequencer. The expansion segment was relatively accessible to modification by both enzymic and chemical probes, suggesting that ES39 was exposed on the surface of the ribosomes. The collected modification data were used in secondary structure modelling of the expansion segment. Despite considerable variation in both sequence and length between organisms from different kingdoms, the structure analysis of the expansion segment gave rise to structural fingerprints that allowed identification of homologous structures in ES39 from fungi, plants and mammals. The homologous structures formed an initial helix and an invariant hairpin connected to the initial helix via a long single-stranded loop. The remaining part of the ES39 sequences accounted for most of the length variation seen between the analysed species. This part could form additional, albeit less similar, hairpins. A comparison of ES39 sequences from other fungi, plants and mammals showed that identical structures could be formed in these organisms. PMID:16473366

Nygård, Odd; Alkemar, Gunnar; Larsson, Sofia L

2006-01-30

207

An Improved Level Set for Liver Segmentation and Perfusion Analysis in MRIs.  

PubMed

Determining liver segmentation accurately from MRIs is the primary and crucial step for any automated liver perfusion analysis, which provides important information about the blood supply to the liver. Although implicit contour extraction methods, such as level set methods (LSMs) and active contours, are often used to segment livers, the results are not always satisfactory due to the presence of artifacts and low-gradient response on the liver boundary. In this paper, we propose a multiple-initialization, multiple-step LSM to overcome the leakage and over-segmentation problems. The multiple-initialization curves are first evolved separately using the fast marching methods and LSMs, which are then combined with a convex hull algorithm to obtain a rough liver contour. Finally, the contour is evolved again using global level set smoothing to determine a precise liver boundary. Experimental results on 12 abdominal MRI series showed that the proposed approach obtained better liver segmentation results, so that a refined liver perfusion curve without respiration affection can be obtained by using a modified chamfer matching algorithm and the perfusion curve is evaluated by radiologists. PMID:19129028

Chen, Gang; Gu, Lixu; Qian, Lijun; Xu, Jianrong

2009-01-01

208

Automated segmentation of muscle and adipose tissue on CT images for human body composition analysis  

NASA Astrophysics Data System (ADS)

The ability to compute body composition in cancer patients lends itself to determining the specific clinical outcomes associated with fat and lean tissue stores. For example, a wasting syndrome of advanced disease associates with shortened survival. Moreover, certain tissue compartments represent sites for drug distribution and are likely determinants of chemotherapy efficacy and toxicity. CT images are abundant, but these cannot be fully exploited unless there exist practical and fast approaches for tissue quantification. Here we propose a fully automated method for segmenting muscle, visceral and subcutaneous adipose tissues, taking the approach of shape modeling for the analysis of skeletal muscle. Muscle shape is represented using PCA encoded Free Form Deformations with respect to a mean shape. The shape model is learned from manually segmented images and used in conjunction with a tissue appearance prior. VAT and SAT are segmented based on the final deformed muscle shape. In comparing the automatic and manual methods, coefficients of variation (COV) (1 - 2%), were similar to or smaller than inter- and intra-observer COVs reported for manual segmentation.

Chung, Howard; Cobzas, Dana; Birdsell, Laura; Lieffers, Jessica; Baracos, Vickie

2009-02-01

209

Oscillatory correlation for scene segmentation of hyperspectral imagery for geospatial analysis  

NASA Astrophysics Data System (ADS)

A neurodynamical approach to scene segmentation of hyperspectral imagery is investigated based on oscillatory correlation theory. A network of relaxation oscillators, which is based on the Locally Excitatory Globally Inhibitory Oscillator Network (LEGION), is extended to process multiband data and it is implemented to perform unsupervised scene segmentation using both spatial and spectral information. The nonlinear dynamical network is capable of achieving segmentation of objects in a scene by the synchronization of oscillators that receive local excitatory inputs from a collection of local neighbors and desynchronization between oscillators corresponding to different objects. The original LEGION model was designed for single-band imagery. The proposed multiband version of LEGION is implemented such that the connections in the oscillator network receive the spectral pixel vectors in the hyperspectral data as excitatory inputs. Euclidean distances between spectra in local neighborhoods are used as the measure of closeness in the network. The ability of the proposed approach to perform natural and urban scene segmentation for geospatial analysis is assessed. Our approach is tested on two hyperspectral datasets with notably different sensor properties and scene content.

Rand, Robert S.

2010-08-01

210

Diversion Path Analysis Handbook. Volume I. Methodology.  

National Technical Information Service (NTIS)

Diversion Path Analysis (DPA) is a procedure for analyzing internal controls of a facility in order to identify vulnerabilities to successful diversion of material by an adversary. The internal covert threat is addressed but the results are also applicabl...

M. D. K. Maltese K. E. Goodwin J. C. Schleter

1976-01-01

211

3-D segmentation of the rim and cup in spectral-domain optical coherence tomography volumes of the optic nerve head  

NASA Astrophysics Data System (ADS)

Glaucoma is a group of diseases which can cause vision loss and blindness due to gradual damage to the optic nerve. The ratio of the optic disc cup to the optic disc is an important structural indicator for assessing the presence of glaucoma. The purpose of this study is to develop and evaluate a method which can segment the optic disc cup and neuroretinal rim in spectral-domain OCT scans centered on the optic nerve head. Our method starts by segmenting 3 intraretinal surfaces using a fast multiscale 3-D graph search method. Based on one of the segmented surfaces, the retina of the OCT volume is flattened to have a consistent shape across scans and patients. Selected features derived from OCT voxel intensities and intraretinal surfaces were used to train a k-NN classifier that can determine which A-scans in the OCT volume belong to the background, optic disc cup and neuroretinal rim. Through 3-fold cross validation with a training set of 20 optic nerve head-centered OCT scans (10 right eye scans and 10 left eye scans from 10 glaucoma patients) and a testing set of 10 OCT scans (5 right eye scans and 5 left eye scans from 5 different glaucoma patients), segmentation results of the optic disc cup and rim for all 30 OCT scans were obtained. The average unsigned errors of the optic disc cup and rim were 1.155 +/- 1.391 pixels (0.035 +/- 0.042 mm) and 1.295 +/- 0.816 pixels (0.039 +/- 0.024 mm), respectively.

Lee, Kyungmoo; Niemeijer, Meindert; Garvin, Mona K.; Kwon, Young H.; Sonka, Milan; Abràmoff, Michael D.

2009-02-01

212

An EM framework for segmentation of tissue mixtures from medical images  

Microsoft Academic Search

Image segmentation plays a major role in quantitative image analysis and computer aided detection (CAD) and diagnosis (CADx) for clinical applications. Conventional segmentation assigns a single label to each voxel, neglecting the partial volume (PV) effect. This work presents an EM (expectation maximization) framework for segmentation of tissue mixture in each voxel. Image data and tissue mixture models, EM algorithm

Zhengrong Liang; Xiang Li; Daria Eremina; Lihong Li

2003-01-01

213

Histological analysis of the callogenesis and organogenesis from root segments of Curcuma zedoaria Roscoe  

Microsoft Academic Search

Callus was induced from root segments taken from in vitro grown plants of Curcuma zedoaria Roscoe. The explants were cultured on agar-solidified Murashige and Skoog medium supplemented with 13.4?M of ?-naphthaleneacetic acid and 2.2?M of 6-benzylaminopurine at 25ºC in the dark. Histological analysis revealed that callus was formed from the hypertrophied cortical parenchyma cells of the explant. Some of these

Marcia O. Mello; Murilo Melo; Beatriz Appezzato-da-Glória

2001-01-01

214

Statistical deformable models for cardiac Segmentation and Functional Analysis In Gated-Spect Studies  

Microsoft Academic Search

This chapter describes the use of statistical deformable models for cardiac segmentation and functional analysis in Gated\\u000a Single Positron Emission Computer Tomography (SPECT) perfusion studies. By means of a statistical deformable model, automatic\\u000a delineations of the endo- and epicardial boundaries of the left ventricle (LV) are obtained, in all temporal phases and image\\u000a slices of the dynamic study. Apriori spatio-temporal

Catalina Tobon-Gomez; S. Ordas; A. Frangi; S. Aguade; J. Castell

215

Concept Area One Objectives (Rev), Test Items (Rev), and Instructional Events. Economic Analysis Course. Segments 1 - 16.  

ERIC Educational Resources Information Center

A multimedia course in economic analysis was prepared and used in conjunction with the United States Naval Academy. (See ED 043 790 and ED 043 791 for final reports of the project evaluation and the development model.) This report presents the first concept area--basic principles--in 24 segments, of which eight are "enrichment segments." The…

Sterling Inst., Washington, DC. Educational Technology Center.

216

Sequence analysis of the medium RNA segment of three Simbu serogroup viruses, Akabane, Aino, and Peaton viruses  

Microsoft Academic Search

The sequence analysis was carried out for the medium (M) RNA segment of the Akabane virus (AKAV), Aino virus (AINV), and Peaton virus (PEAV) of the Simbu serogroup of the genus Orthobunyavirus of the family Bunyaviridae. The complementary sequences of the M RNA segments of AKAV, AINV, and PEAV contain a single large open reading frame (ORF), like other orthobunyaviruses.

Tohru Yanase; Kazuo Yoshida; Seiichi Ohashi; Tomoko Kato; Tomoyuki Tsuda

2003-01-01

217

Optimal analysis for segmented mirror capture and alignment in space optics system  

Microsoft Academic Search

A great deal segmented mirror errors consisting of piston and tip-tilt exist when space large aperture segmented optics system deploys. These errors will result in the departure of segmented mirrors images from the view. For that, proper scanning function should be adopted to control actuators rotating the segmented mirror, so that the images of segmented mirror can be put into

Xiaofang Zhang; Xin Yu; Xia Wang; Lei Zhao

2008-01-01

218

Diversion path analysis handbook. Volume I. Methodology  

Microsoft Academic Search

Diversion Path Analysis (DPA) is a procedure for analyzing internal controls of a facility in order to identify vulnerabilities to successful diversion of material by an adversary. The internal covert threat is addressed but the results are also applicable to the external overt threat. The diversion paths are identified. Complexity parameters include records alteration or falsification, multiple removals of sub-threshold

M. D. K. Maltese; K. E. Goodwin; J. C. Schleter

1976-01-01

219

Texture analysis based on the Hermite transform for image classification and segmentation  

NASA Astrophysics Data System (ADS)

Texture analysis has become an important task in image processing because it is used as a preprocessing stage in different research areas including medical image analysis, industrial inspection, segmentation of remote sensed imaginary, multimedia indexing and retrieval. In order to extract visual texture features a texture image analysis technique is presented based on the Hermite transform. Psychovisual evidence suggests that the Gaussian derivatives fit the receptive field profiles of mammalian visual systems. The Hermite transform describes locally basic texture features in terms of Gaussian derivatives. Multiresolution combined with several analysis orders provides detection of patterns that characterizes every texture class. The analysis of the local maximum energy direction and steering of the transformation coefficients increase the method robustness against the texture orientation. This method presents an advantage over classical filter bank design because in the latter a fixed number of orientations for the analysis has to be selected. During the training stage, a subset of the Hermite analysis filters is chosen in order to improve the inter-class separability, reduce dimensionality of the feature vectors and computational cost during the classification stage. We exhaustively evaluated the correct classification rate of real randomly selected training and testing texture subsets using several kinds of common used texture features. A comparison between different distance measurements is also presented. Results of the unsupervised real texture segmentation using this approach and comparison with previous approaches showed the benefits of our proposal.

Estudillo-Romero, Alfonso; Escalante-Ramirez, Boris; Savage-Carmona, Jesus

2012-05-01

220

Multiwell experiment: reservoir modeling analysis, Volume II  

SciTech Connect

This report updates an ongoing analysis by reservoir modelers at the Morgantown Energy Technology Center (METC) of well test data from the Department of Energy's Multiwell Experiment (MWX). Results of previous efforts were presented in a recent METC Technical Note (Horton 1985). Results included in this report pertain to the poststimulation well tests of Zones 3 and 4 of the Paludal Sandstone Interval and the prestimulation well tests of the Red and Yellow Zones of the Coastal Sandstone Interval. The following results were obtained by using a reservoir model and history matching procedures: (1) Post-minifracture analysis indicated that the minifracture stimulation of the Paludal Interval did not produce an induced fracture, and extreme formation damage did occur, since a 65% permeability reduction around the wellbore was estimated. The design for this minifracture was from 200 to 300 feet on each side of the wellbore; (2) Post full-scale stimulation analysis for the Paludal Interval also showed that extreme formation damage occurred during the stimulation as indicated by a 75% permeability reduction 20 feet on each side of the induced fracture. Also, an induced fracture half-length of 100 feet was determined to have occurred, as compared to a designed fracture half-length of 500 to 600 feet; and (3) Analysis of prestimulation well test data from the Coastal Interval agreed with previous well-to-well interference tests that showed extreme permeability anisotropy was not a factor for this zone. This lack of permeability anisotropy was also verified by a nitrogen injection test performed on the Coastal Red and Yellow Zones. 8 refs., 7 figs., 2 tabs.

Horton, A.I.

1985-05-01

221

Segmentation of 3D Objects from MRI Volume Data Using Constrained Elastic Deformations of Flexible Fourier Surface Models  

Microsoft Academic Search

This paper describes a new model-based segmentation techniquecombining desirable properties of physical models (snakes, [2]),shape representation by Fourier parametrization (Fourier snakes, [12]),and modelling of natural shape variability (eigenmodes, [7, 10]). Flexibleshape models are represented by a parameter vector describing the meancontour and by a set of eigenmodes of the parameters characterizing theshape variation with respect to a small set of

Gábor Székely; András Kelemen; Christian Brechbühler; Guido Gerig

1995-01-01

222

Comparative analysis of nonlinear dimensionality reduction techniques for breast MRI segmentation  

SciTech Connect

Purpose: Visualization of anatomical structures using radiological imaging methods is an important tool in medicine to differentiate normal from pathological tissue and can generate large amounts of data for a radiologist to read. Integrating these large data sets is difficult and time-consuming. A new approach uses both supervised and unsupervised advanced machine learning techniques to visualize and segment radiological data. This study describes the application of a novel hybrid scheme, based on combining wavelet transform and nonlinear dimensionality reduction (NLDR) methods, to breast magnetic resonance imaging (MRI) data using three well-established NLDR techniques, namely, ISOMAP, local linear embedding (LLE), and diffusion maps (DfM), to perform a comparative performance analysis. Methods: Twenty-five breast lesion subjects were scanned using a 3T scanner. MRI sequences used were T1-weighted, T2-weighted, diffusion-weighted imaging (DWI), and dynamic contrast-enhanced (DCE) imaging. The hybrid scheme consisted of two steps: preprocessing and postprocessing of the data. The preprocessing step was applied for B{sub 1} inhomogeneity correction, image registration, and wavelet-based image compression to match and denoise the data. In the postprocessing step, MRI parameters were considered data dimensions and the NLDR-based hybrid approach was applied to integrate the MRI parameters into a single image, termed the embedded image. This was achieved by mapping all pixel intensities from the higher dimension to a lower dimensional (embedded) space. For validation, the authors compared the hybrid NLDR with linear methods of principal component analysis (PCA) and multidimensional scaling (MDS) using synthetic data. For the clinical application, the authors used breast MRI data, comparison was performed using the postcontrast DCE MRI image and evaluating the congruence of the segmented lesions. Results: The NLDR-based hybrid approach was able to define and segment both synthetic and clinical data. In the synthetic data, the authors demonstrated the performance of the NLDR method compared with conventional linear DR methods. The NLDR approach enabled successful segmentation of the structures, whereas, in most cases, PCA and MDS failed. The NLDR approach was able to segment different breast tissue types with a high accuracy and the embedded image of the breast MRI data demonstrated fuzzy boundaries between the different types of breast tissue, i.e., fatty, glandular, and tissue with lesions (>86%). Conclusions: The proposed hybrid NLDR methods were able to segment clinical breast data with a high accuracy and construct an embedded image that visualized the contribution of different radiological parameters.

Akhbardeh, Alireza; Jacobs, Michael A. [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 (United States); Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 (United States) and Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 (United States)

2012-04-15

223

Multivariate statistical analysis as a tool for the segmentation of 3D spectral data.  

PubMed

Acquisition of three-dimensional (3D) spectral data is nowadays common using many different microanalytical techniques. In order to proceed to the 3D reconstruction, data processing is necessary not only to deal with noisy acquisitions but also to segment the data in term of chemical composition. In this article, we demonstrate the value of multivariate statistical analysis (MSA) methods for this purpose, allowing fast and reliable results. Using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) coupled with a focused ion beam (FIB), a stack of spectrum images have been acquired on a sample produced by laser welding of a nickel-titanium wire and a stainless steel wire presenting a complex microstructure. These data have been analyzed using principal component analysis (PCA) and factor rotations. PCA allows to significantly improve the overall quality of the data, but produces abstract components. Here it is shown that rotated components can be used without prior knowledge of the sample to help the interpretation of the data, obtaining quickly qualitative mappings representative of elements or compounds found in the material. Such abundance maps can then be used to plot scatter diagrams and interactively identify the different domains in presence by defining clusters of voxels having similar compositions. Identified voxels are advantageously overlaid on secondary electron (SE) images with higher resolution in order to refine the segmentation. The 3D reconstruction can then be performed using available commercial softwares on the basis of the provided segmentation. To asses the quality of the segmentation, the results have been compared to an EDX quantification performed on the same data. PMID:24035679

Lucas, G; Burdet, P; Cantoni, M; Hébert, C

2013-08-31

224

MRI segmentation: Methods and applications  

Microsoft Academic Search

The current literature on MRI segmentation methods is reviewed. Particular emphasis is placed on the relative merits of single image versus multispectral segmentation, and supervised versus unsupervised segmentation methods. Image pre-processing and registration are discussed, as well as methods of validation. The application of MRI segmentation for tumor volume measurements during the course of therapy is presented here as an

L. P. Clarke; R. P. Velthuizen; M. A. Camacho; J. J. Heine; M. Vaidyanathan; L. O. Hall; R. W. Thatcher; M. L. Silbiger

1995-01-01

225

Profiling the different needs and expectations of patients for population-based medicine: a case study using segmentation analysis  

PubMed Central

Background This study illustrates an evidence-based method for the segmentation analysis of patients that could greatly improve the approach to population-based medicine, by filling a gap in the empirical analysis of this topic. Segmentation facilitates individual patient care in the context of the culture, health status, and the health needs of the entire population to which that patient belongs. Because many health systems are engaged in developing better chronic care management initiatives, patient profiles are critical to understanding whether some patients can move toward effective self-management and can play a central role in determining their own care, which fosters a sense of responsibility for their own health. A review of the literature on patient segmentation provided the background for this research. Method First, we conducted a literature review on patient satisfaction and segmentation to build a survey. Then, we performed 3,461 surveys of outpatient services users. The key structures on which the subjects’ perception of outpatient services was based were extrapolated using principal component factor analysis with varimax rotation. After the factor analysis, segmentation was performed through cluster analysis to better analyze the influence of individual attitudes on the results. Results Four segments were identified through factor and cluster analysis: the “unpretentious,” the “informed and supported,” the “experts” and the “advanced” patients. Their policies and managerial implications are outlined. Conclusions With this research, we provide the following: – a method for profiling patients based on common patient satisfaction surveys that is easily replicable in all health systems and contexts; – a proposal for segments based on the results of a broad-based analysis conducted in the Italian National Health System (INHS). Segments represent profiles of patients requiring different strategies for delivering health services. Their knowledge and analysis might support an effort to build an effective population-based medicine approach.

2012-01-01

226

Intracranial volume, brain volume, reserve volume and morphological signs of increased intracranial pressure – A post-mortem analysis  

Microsoft Academic Search

In a series of 93 unselected forensic autopsies of adults the following volumes were measured: skull volume by filling a sac of synthetic material with water, placed intracranially, after removal of the brain and brain volume by its water displacement. Objective was to demonstrate if generally is there a relation between reduced difference of skull volume minus cerebral volume (“reserve

H. Maxeiner; M. Behnke

2008-01-01

227

Automatic segmentation and analysis of fibrin networks in 3D confocal microscopy images  

NASA Astrophysics Data System (ADS)

Fibrin networks are a major component of blood clots that provides structural support to the formation of growing clots. Abnormal fibrin networks that are too rigid or too unstable can promote cardiovascular problems and/or bleeding. However, current biological studies of fibrin networks rarely perform quantitative analysis of their structural properties (e.g., the density of branch points) due to the massive branching structures of the networks. In this paper, we present a new approach for segmenting and analyzing fibrin networks in 3D confocal microscopy images. We first identify the target fibrin network by applying the 3D region growing method with global thresholding. We then produce a one-voxel wide centerline for each fiber segment along which the branch points and other structural information of the network can be obtained. Branch points are identified by a novel approach based on the outer medial axis. Cells within the fibrin network are segmented by a new algorithm that combines cluster detection and surface reconstruction based on the ?-shape approach. Our algorithm has been evaluated on computer phantom images of fibrin networks for identifying branch points. Experiments on z-stack images of different types of fibrin networks yielded results that are consistent with biological observations.

Liu, Xiaomin; Mu, Jian; Machlus, Kellie R.; Wolberg, Alisa S.; Rosen, Elliot D.; Xu, Zhiliang; Alber, Mark S.; Chen, Danny Z.

2012-02-01

228

Cost-Volume-Profit Analysis Adjusted for Learning  

Microsoft Academic Search

A model is developed for cost-volume-profit analysis which incorporates a nonlinear cost function to express the effects of employee learning. Sensitivity analysis is applied to the model to assess the impact of estimation errors in the learning rate and steady-state production time on estimated profit and break-even quantities. The paper also examines the effects on the model of (1) alternative

E. V. McIntyre

1977-01-01

229

Feature-driven model-based segmentation  

NASA Astrophysics Data System (ADS)

The accurate delineation of anatomical structures is required in many medical image analysis applications. One example is radiation therapy planning (RTP), where traditional manual delineation is tedious, labor intensive, and can require hours of clinician's valuable time. Majority of automated segmentation methods in RTP belong to either model-based or atlas-based approaches. One substantial limitation of model-based segmentation is that its accuracy may be restricted by the uncertainties in image content, specifically when segmenting low-contrast anatomical structures, e.g. soft tissue organs in computed tomography images. In this paper, we introduce a non-parametric feature enhancement filter which replaces raw intensity image data by a high level probabilistic map which guides the deformable model to reliably segment low-contrast regions. The method is evaluated by segmenting the submandibular and parotid glands in the head and neck region and comparing the results to manual segmentations in terms of the volume overlap. Quantitative results show that we are in overall good agreement with expert segmentations, achieving volume overlap of up to 80%. Qualitatively, we demonstrate that we are able to segment low-contrast regions, which otherwise are difficult to delineate with deformable models relying on distinct object boundaries from the original image data.

Qazi, Arish A.; Kim, John; Jaffray, David A.; Pekar, Vladimir

2011-03-01

230

Automatic Segmentation and Quantitative Analysis of the Articular Cartilages From Magnetic Resonance Images of the Knee  

Microsoft Academic Search

In this paper, we present a segmentation scheme that automatically and accurately segments all the cartilages from magnetic resonance (MR) images of nonpathological knees. Our scheme involves the automatic segmentation of the bones using a three-dimensional active shape model, the extraction of the expected bone-cartilage interface (BCI), and cartilage segmentation from the BCI using a deformable model that utilizes localization,

Jurgen Fripp; Stuart Crozier; Simon K. Warfield; Sébastien Ourselin

2010-01-01

231

SPECT and PET analysis of subthalamic stimulation in Parkinson's disease: analysis using a manual segmentation.  

PubMed

The subthalamic nucleus (STN) has become an effective target of deep-brain stimulation (DBS) in severely disabled patients with advanced Parkinson's disease (PD). Clinical studies have reported DBS-induced adverse effects on cognitive functions, mood, emotion and behavior. STN DBS seems to interfere with the limbic functions of the basal ganglia, but the limbic effects of STN DBS are controversial. We measured prospectively resting regional cerebral metabolism (rCMb) with 18-fluorodeoxyglucose and PET, and resting regional cerebral blood flow (rCBF) with HMPAO and SPECT in six patients with Parkinson's disease. We compared PET and SPECT 1 month before and 3 months after STN DBS. On cerebral MRI, 13 regions of interest (ROI) were manually delineated slice by slice in frontal and limbic lobes. We obtained mean rCBF and rCMb values for each ROI and the whole brain. We normalized rCBF and rCMB values to ones for the whole brain volume, which we compared before and following STN DBS. No significant difference emerged in the SPECT analysis. PET analysis revealed a significant decrease in rCMb following STN DBS in the superior frontal gyri and left and right dorsolateral prefrontal cortex (p < 0.05). A non-significant decrease in rCMb in the left anterior cingulate gyrus appeared following STN DBS (p = 0.075). Our prospective SPECT and PET study revealed significantly decreased glucose metabolism of the two superior frontal gyri without any attendant perfusion changes following STN DBS. These results suggest that STN DBS may change medial prefrontal function and therefore the integration of limbic information, either by disrupting emotional processes within the STN, or by hampering the normal function of a limbic circuit. PMID:19774437

Haegelen, Claire; García-Lorenzo, Daniel; Le Jeune, Florence; Péron, Julie; Gibaud, Bernard; Riffaud, Laurent; Brassier, Gilles; Barillot, Christian; Vérin, Marc; Morandi, Xavier

2009-09-23

232

Segmental ion spray LC-MS-MS analysis of benzodiazepines in hair of psychiatric patients.  

PubMed

The aim of this study was to develop a liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the analysis of benzodiazepines in human hair. The method was tested by analyzing hair samples from forensic and clinical psychiatric patients where benzodiazepines had been prescribed during hospitalization and after care. Hair samples were obtained at discharge from the clinic and then after six months. Two-centimeter segments of the hair samples (10-30 mg) were washed once with isopropanol, three times with phosphate buffer, and again with isopropanol, dried, weighed, and digested with proteinase K before solid-phase extraction with BondElut Certify columns. Diazepam, nordiazepam, oxazepam, alprazolam, OH-alprazolam, nitrazepam, 7-aminonitrazepam, flunitrazepam, 7-aminoflunitrazepam, clonazepam, and 7-aminoclonazepam were quantitated in MRM mode using one transition for each analyte and deuterated internal standard. The calibration range was 0.125-5 ng/mg for diazepam, nordiazepam, and oxazepam and 0.025-1.0 ng/mg for the other compounds. In the hair samples analyzed, diazepam, flunitrazepam, nitrazepam, and clonazepam was detected together with their metabolites. Alprazolam was not detected in any sample. Segmental hair analysis revealed differences in drug deposition in hair before and after release from psychiatric treatment. Both increases and decreases of hair drug concentrations were seen after release even though the prescribed dose was the same. This was taken as an indication of noncompliance during the after-care period. We conclude that the extraction and LC-MS-MS procedures were adequate to detect benzodiazepines in hair and that the results indicated that segmental hair analysis might provide retrospective information about medication intake. PMID:12423003

Kronstrand, Robert; Nyström, Ingrid; Josefsson, Martin; Hodgins, Sheilagh

2002-10-01

233

Automatic 3-D grayscale volume matching and shape analysis.  

PubMed

Recently, shape matching in three dimensions (3-D) has been gaining importance in a wide variety of fields such as computer graphics, computer vision, medicine, and biology, with applications such as object recognition, medical diagnosis, and quantitative morphological analysis of biological operations. Automatic shape matching techniques developed in the field of computer graphics handle object surfaces, but ignore intensities of inner voxels. In biology and medical imaging, voxel intensities obtained by computed tomography (CT), magnetic resonance imagery (MRI), and confocal microscopes are important to determine point correspondences. Nevertheless, most biomedical volume matching techniques require human interactions, and automatic methods assume matched objects to have very similar shapes so as to avoid combinatorial explosions of point. This article is aimed at decreasing the gap between the two fields. The proposed method automatically finds dense point correspondences between two grayscale volumes; i.e., finds a correspondent in the second volume for every voxel in the first volume, based on the voxel intensities. Mutiresolutional pyramids are introduced to reduce computational load and handle highly plastic objects. We calculate the average shape of a set of similar objects and give a measure of plasticity to compare them. Matching results can also be used to generate intermediate volumes for morphing. We use various data to validate the effectiveness of our method: we calculate the average shape and plasticity of a set of fly brain cells, and we also match a human skull and an orangutan skull. PMID:16617625

Guétat, Grégoire; Maitre, Matthieu; Joly, Laurène; Lai, Sen-Lin; Lee, Tzumin; Shinagawa, Yoshihisa

2006-04-01

234

A high-resolution anisotropic finite-volume head model for EEG source analysis.  

PubMed

Solution of the electroencephalogram (EEG) forward problem in a realistic head model is necessary for accurate source analysis. Realistic head models are usually derived from volumetric magnetic resonance images that provide a voxel resolution of about 1 mm3. The availability of an electrical head model with this resolution would therefore be extremely advantageous. Head models with resolution in the millimeter range that incorporate the anisotropic properties of their elements have been formulated with the finite element method (FEM). However, these FEM models are fraught with complications related to irregular grids and meshes, along with the incumbent segmentation problems. Presented here is a finite volume method (FVM) formulation of the realistic head model in cubic elements that can ameliorate some of these problems, can incorporate tissue anisotropy, and is both physically intuitive and simple to implement. PMID:17947096

Cook, Michael J D; Koles, Zoltan J

2006-01-01

235

Old document image segmentation using the autocorrelation function and multiresolution analysis  

NASA Astrophysics Data System (ADS)

Recent progress in the digitization of heterogeneous collections of ancient documents has rekindled new challenges in information retrieval in digital libraries and document layout analysis. Therefore, in order to control the quality of historical document image digitization and to meet the need of a characterization of their content using intermediate level metadata (between image and document structure), we propose a fast automatic layout segmentation of old document images based on five descriptors. Those descriptors, based on the autocorrelation function, are obtained by multiresolution analysis and used afterwards in a specific clustering method. The method proposed in this article has the advantage that it is performed without any hypothesis on the document structure, either about the document model (physical structure), or the typographical parameters (logical structure). It is also parameter-free since it automatically adapts to the image content. In this paper, firstly, we detail our proposal to characterize the content of old documents by extracting the autocorrelation features in the different areas of a page and at several resolutions. Then, we show that is possible to automatically find the homogeneous regions defined by similar indices of autocorrelation without knowledge about the number of clusters using adapted hierarchical ascendant classification and consensus clustering approaches. To assess our method, we apply our algorithm on 316 old document images, which encompass six centuries (1200-1900) of French history, in order to demonstrate the performance of our proposal in terms of segmentation and characterization of heterogeneous corpus content. Moreover, we define a new evaluation metric, the homogeneity measure, which aims at evaluating the segmentation and characterization accuracy of our methodology. We find a 85% of mean homogeneity accuracy. Those results help to represent a document by a hierarchy of layout structure and content, and to define one or more signatures for each page, on the basis of a hierarchical representation of homogeneous blocks and their topology.

Mehri, Maroua; Gomez-Krämer, Petra; Héroux, Pierre; Mullot, Rémy

2013-01-01

236

Quantitative analysis of volume images: electron microscopic tomography of HIV  

NASA Astrophysics Data System (ADS)

Three-dimensional objects should be represented by 3D images. So far, most of the evaluation of images of 3D objects have been done visually, either by looking at slices through the volumes or by looking at 3D graphic representations of the data. In many applications a more quantitative evaluation would be valuable. Our application is the analysis of volume images of the causative agent of the acquired immune deficiency syndrome (AIDS), namely human immunodeficiency virus (HIV), produced by electron microscopic tomography (EMT). A structural analysis of the virus is of importance. The representation of some of the interesting structural features will depend on the orientation and the position of the object relative to the digitization grid. We describe a method of defining orientation and position of objects based on the moment of inertia of the objects in the volume image. In addition to a direct quantification of the 3D object a quantitative description of the convex deficiency may provide valuable information about the geometrical properties. The convex deficiency is the volume object subtracted from its convex hull. We describe an algorithm for creating an enclosing polyhedron approximating the convex hull of an arbitrarily shaped object.

Nystrom, Ingela; Bengtsson, Ewert W.; Nordin, Bo G.; Borgefors, Gunilla

1994-05-01

237

A novel method for the measurement of linear body segment parameters during clinical gait analysis.  

PubMed

Clinical gait analysis is a valuable tool for the understanding of motion disorders and treatment outcomes. Most standard models used in gait analysis rely on predefined sets of body segment parameters that must be measured on each individual. Traditionally, these parameters are measured using calipers and tape measures. The process can be time consuming and is prone to several sources of error. This investigation explored a novel method for rapid recording of linear body segment parameters using magnetic-field based digital calipers commonly used for a different purpose in prosthetics and orthotics. The digital method was found to be comparable to traditional in all linear measures and data capture was significantly faster with the digital method, with mean time savings for 10 measurements of 2.5min. Digital calipers only record linear distances, and were less accurate when diameters were used to approximate limb circumferences. Experience in measuring BSPs is important, as an experienced measurer was significantly faster than a graduate student and showed less difference between methods. Comparing measurement of adults vs. children showed greater differences with adults, and some method-dependence. If the hardware is available, digital caliper measurement of linear BSPs is accurate and rapid. PMID:23602545

Geil, Mark D

2013-04-18

238

Lagged segmented Poincaré plot analysis for risk stratification in patients with dilated cardiomyopathy.  

PubMed

The objectives of this study were to introduce a new type of heart-rate variability analysis improving risk stratification in patients with idiopathic dilated cardiomyopathy (DCM) and to provide additional information about impaired heart beat generation in these patients. Beat-to-beat intervals (BBI) of 30-min ECGs recorded from 91 DCM patients and 21 healthy subjects were analyzed applying the lagged segmented Poincaré plot analysis (LSPPA) method. LSPPA includes the Poincaré plot reconstruction with lags of 1-100, rotating the cloud of points, its normalized segmentation adapted to their standard deviations, and finally, a frequency-dependent clustering. The lags were combined into eight different clusters representing specific frequency bands within 0.012-1.153 Hz. Statistical differences between low- and high-risk DCM could be found within the clusters II-VIII (e.g., cluster IV: 0.033-0.038 Hz; p = 0.0002; sensitivity = 85.7 %; specificity = 71.4 %). The multivariate statistics led to a sensitivity of 92.9 %, specificity of 85.7 % and an area under the curve of 92.1 % discriminating these patient groups. We introduced the LSPPA method to investigate time correlations in BBI time series. We found that LSPPA contributes considerably to risk stratification in DCM and yields the highest discriminant power in the low and very low-frequency bands. PMID:22689265

Voss, Andreas; Fischer, Claudia; Schroeder, Rico; Figulla, Hans R; Goernig, Matthias

2012-06-12

239

Deconvolution Analysis of Cardiac Natriuretic Peptides During Acute Volume Overload  

Microsoft Academic Search

Cardiac natriuretic peptides, especially amino terminal pro-Brain Natriuretic Peptide (NT-proBNP), are emerging as powerful circulating markers of cardiac function. However, the in vivo secretion and elimination (t 1? 2 )o f these peptides during acute volume overload have not been studied. We present the first report of the secretion and elimination of cardiac natriuretic peptides, based on deconvolution analysis of

Chris J. Pemberton; Michael L. Johnson; Tim G. Yandle; Eric A. Espiner

2010-01-01

240

Dealing with Fuzziness in Cost-Volume-Profit Analysis  

Microsoft Academic Search

A major limitation of the traditional cost-volume-profit (CVP) analysis is its inability to account for uncertainty and risk. This deficiency has been resolved by the development of probabilistic and stochastic CVP models which require precise numerical assessment of uncertainties in sales demand. There remains, however, imprecision in the expert's assessment of the sales demand distribution. Sub-optimal decisions may result because

Y. Lilian Chan; Yufei Yuan

1990-01-01

241

Welsh Hotel: Cost-Volume-Profit Analysis and Uncertainty  

Microsoft Academic Search

Hotels tend to have a high level of fixed costs, which means that high losses will result if revenue is significantly reduced below the break-even point. Hence, the traditional cost-volume-profit (CVP) model, which is widely used within the hotel sector to determine break-even analysis, is an important managerial tool. However, is the basic CVP model adequate, bearing in mind that

Paul A. Phillips

1994-01-01

242

Shared genomic segment analysis. Mapping disease predisposition genes in extended pedigrees using SNP genotype assays.  

PubMed

We examine the utility of high density genotype assays for predisposition gene localization using extended pedigrees. Results for the distribution of the number and length of genomic segments shared identical by descent among relatives previously derived in the context of genomic mismatch scanning are reviewed in the context of dense single nucleotide polymorphism maps. We use long runs of loci at which cases share a common allele identically by state to localize hypothesized predisposition genes. The distribution of such runs under the hypothesis of no genetic effect is evaluated by simulation. Methods are illustrated by analysis of an extended prostate cancer pedigree previously reported to show significant linkage to chromosome 1p23. Our analysis establishes that runs of simple single locus statistics can be powerful, tractable and robust for finding DNA shared between relatives, and that extended pedigrees offer powerful designs for gene detection based on these statistics. PMID:18093282

Thomas, A; Camp, N J; Farnham, J M; Allen-Brady, K; Cannon-Albright, L A

2007-12-18

243

Semi-automatic segmentation and modeling of the cervical spinal cord for volume quantification in multiple sclerosis patients from magnetic resonance images  

NASA Astrophysics Data System (ADS)

Spinal cord (SC) tissue loss is known to occur in some patients with multiple sclerosis (MS), resulting in SC atrophy. Currently, no measurement tools exist to determine the magnitude of SC atrophy from Magnetic Resonance Images (MRI). We have developed and implemented a novel semi-automatic method for quantifying the cervical SC volume (CSCV) from Magnetic Resonance Images (MRI) based on level sets. The image dataset consisted of SC MRI exams obtained at 1.5 Tesla from 12 MS patients (10 relapsing-remitting and 2 secondary progressive) and 12 age- and gender-matched healthy volunteers (HVs). 3D high resolution image data were acquired using an IR-FSPGR sequence acquired in the sagittal plane. The mid-sagittal slice (MSS) was automatically located based on the entropy calculation for each of the consecutive sagittal slices. The image data were then pre-processed by 3D anisotropic diffusion filtering for noise reduction and edge enhancement before segmentation with a level set formulation which did not require re-initialization. The developed method was tested against manual segmentation (considered ground truth) and intra-observer and inter-observer variability were evaluated.

Sonkova, Pavlina; Evangelou, Iordanis E.; Gallo, Antonio; Cantor, Fredric K.; Ohayon, Joan; McFarland, Henry F.; Bagnato, Francesca

2008-04-01

244

Incorporation of texture-based features in optimal graph-theoretic approach with application to the 3D segmentation of intraretinal surfaces in SD-OCT volumes  

NASA Astrophysics Data System (ADS)

While efficient graph-theoretic approaches exist for the optimal (with respect to a cost function) and simultaneous segmentation of multiple surfaces within volumetric medical images, the appropriate design of cost functions remains an important challenge. Previously proposed methods have used simple cost functions or optimized a combination of the same, but little has been done to design cost functions using learned features from a training set, in a less biased fashion. Here, we present a method to design cost functions for the simultaneous segmentation of multiple surfaces using the graph-theoretic approach. Classified texture features were used to create probability maps, which were incorporated into the graph-search approach. The efficiency of such an approach was tested on 10 optic nerve head centered optical coherence tomography (OCT) volumes obtained from 10 subjects that presented with glaucoma. The mean unsigned border position error was computed with respect to the average of manual tracings from two independent observers and compared to our previously reported results. A significant improvement was noted in the overall means which reduced from 9.25 +/- 4.03?m to 6.73 +/- 2.45?m (p < 0.01) and is also comparable with the inter-observer variability of 8.85 +/- 3.85?m.

Antony, Bhavna J.; Abràmoff, Michael D.; Sonka, Milan; Kwon, Young H.; Garvin, Mona K.

2012-02-01

245

Phenotypic analysis using very small volumes of blood.  

PubMed

Analysis of cell-surface phenotype of peripheral blood leukocytes is one of the most common applications of flow cytometry. In mouse research, the small size of the animal limits the amount of blood available. Standard staining methods using lysis of erythrocytes or gradient separation followed by repeated washing involve unavoidable losses of cells that generally limit analysis of blood to terminal methods. Time-course studies, therefore, require sacrifice of groups of mice at each time point. Thus, a method is needed that can be used with much smaller volumes of blood. This will allow serial sampling of the same animal over time, decreasing experimental variability and reducing animal use. The method described here is a no-lyse, no-wash method that uses triggering on a fluorescence parameter. The method allows routine analysis of the phenotype of peripheral blood leukocytes using whole-blood volumes of 20 µl per tube. The data are comparable with values from traditional methods requiring much higher volumes of blood. Due to interference by erythrocytes, light-scatter parameters are not usable with this method. This method has been used for time-course studies of peripheral blood populations in mice lasting as long as four weeks. PMID:20938921

Weaver, James L; McKinnon, Katherine; Germolec, Dori R

2010-10-01

246

Visual versus Computerized Analysis of Upsloping ST Segment Depression in the Exercise Electrocardiogram  

Microsoft Academic Search

A slowly upsloping ST segment depression is an abnormal, and a rapidly upsloping ST segment depression is a normal exercise ECG response. We investigated the agreement of expert physicians on the visual classification of the ST segment depression, and compared the (majority) vote with the computer-generated ST slope. A total of 206 exercise ECG leads with an amplitude of the

Markku A. Walamies; Tiit Kööbi; Liisa I. Hämäläinen; Esa A. Ahonen

1999-01-01

247

Limb-Segment Selection in Graphic Movements: Part 1: A Space-Domain Analysis.  

National Technical Information Service (NTIS)

The paper examines how people select specific combinations of limb segments to carry out physical tasks. Four determinants of limb-segment selection are hypothesized. First, it is recognized that the range of motion which a limb segment can achieve delimi...

R. G. J. Meulenbroek D. A. Rosenbaum A. J. W. M. Thomassen L. R. Schomaker

1991-01-01

248

Optical image compression based on segmentation of the Fourier plane: new approaches and critical analysis  

Microsoft Academic Search

We present a new optical image compression approach based on spectral selection and using a segmented filter. In order to identify the method offering the best quality of reconstruction of the optically compressed images, we investigated several spectral segmentation methods. The compression is carried out in the spectral domain and results in a compound spectrum referred to as the segmented

S. Soualmi; A. Alfalou; H. Hamam

2007-01-01

249

An Integrated Segmentation and Classification Approach Applied to Multiple Sclerosis Analysis  

Microsoft Academic Search

We present a novel multiscale approach that combines segmentation with classification to detect abnormal brain structures in medical imagery, and demonstrate its utility in detecting multiple sclerosis lesions in 3D MRI data. Our method uses segmentation to obtain a hierarchical decom- position of a multi-channel, anisotropic MRI scan. It then produces a rich set of features describing the segments in

Ayelet Akselrod-ballin; Meirav Galun; Ronen Basri; Achi Brandt; Moshe John Gomori; Massimo Filippi; Paula Valsasina

2006-01-01

250

Hand Image Segmentation in Video Sequence by GMM: a comparative analysis  

Microsoft Academic Search

This paper describes different approaches of real- time GMM (Gaussian Mixture Method) background subtraction algorithm using video sequences for hand image segmentation. In each captured image, the segmentation takes place where pixels belonging to the hands are separated from the background based on background extraction and skin-color segmentation. A time-adaptive mixture of Gaussians is used to model the distribution of

Hebert Luchetti Ribeiro; Adilson Gonzaga

2006-01-01

251

Fiber composite analysis and design. Volume 2: Structures  

SciTech Connect

Recent years have witnessed a significant increase in the understanding and utilization of fibrous composite materials. There has also been a much larger increase in the amount of published literature in this field. This book builds upon existing literature to present a review of the available capability for composite structural design and analysis. The aim is to provide guidance for one who seeks to become familiar with the tools required for designing with fibrous composites. Thus, the book identifies the key concepts associated with the use of these unique materials. This second volume addresses the design and analysis of structural configurations for the practical and efficient utilization of fiber composite materials.

Rosen, B.W.

1998-09-01

252

Public Segmentation and Government–Public Relationship Building: A Cluster Analysis of Publics in the United States and 19 European Countries  

Microsoft Academic Search

The purposes of this study are (a) to suggest a model of public segmentation and (b) to examine each segment's level of trust in government. By using individuals’ cognitive perceptions of government and participation in social organizations, as well as media use and demographic characteristics, as public segmentation criteria, a cluster analysis of international survey datasets of the United States

Hyehyun Hong; Youngah Lee; Jongmin Park

2012-01-01

253

Facial expression during emotional monologues in unilateral stroke: an analysis of monologue segments.  

PubMed

Emotional monologues of brain-damaged subjects were examined to determine whether interhemispheric or intrahemispheric differences exist for facial emotional expression. A special feature was the comparison of expressions produced during the initial, middle, and last segments of the monologues. Videotaped emotional and non-emotional monologues from the New York Emotion Battery (Borod, Welkowitz, & Obler, 1992) of eight right brain-damaged (RBD), eight left brain-damaged (LBD), and eight normal control (NC) subjects, with matching for demographics and lesion location, were rated. Five raters were trained to evaluate the emotional intensity and category accuracy of the facial expressions produced during these monologues. Results revealed some support for a reversed valence effect, with RBDs showing relatively less accurate performance during positive monologues. Intrahemispheric results revealed that, overall, RBDs with frontal lobe lesions showed the least intense facial expressions. Segment analysis found that individuals produced facial expressions with significantly more emotional intensity during the middle and last thirds of the monologues than during the initial third of the monologues. Findings indicate intrahemispheric as well as interhemispheric differences in facial emotional expression and suggest the utilization of the latter parts of monologues in the evaluation of emotional expression, which has potential clinical implications. PMID:18067419

Kazandjian, Seta; Borod, Joan C; Brickman, Adam M

2007-01-01

254

Evolutionary analysis of the segment from helix 3 through helix 5 in vertebrate progesterone receptors.  

PubMed

The interaction between helix 3 and helix 5 in the human mineralocorticoid receptor [MR], progesterone receptor [PR] and glucocorticoid receptor [GR] influences their response to steroids. For the human PR, mutations at Gly-722 on helix 3 and Met-759 on helix 5 alter responses to progesterone. We analyzed the evolution of these two sites and the rest of a 59 residue segment containing helices 3, 4 and 5 in vertebrate PRs and found that a glycine corresponding to Gly-722 on helix 3 in human PR first appears in platypus, a monotreme. In lamprey, skates, fish, amphibians and birds, cysteine is found at this position in helix 3. This suggests that the cysteine to glycine replacement in helix 3 in the PR was important in the evolution of mammals. Interestingly, our analysis of the rest of the 59 residue segment finds 100% sequence conservation in almost all mammal PRs, substantial conservation in reptile and amphibian PRs and divergence of land vertebrate PR sequences from the fish PR sequences. The differences between fish and land vertebrate PRs may be important in the evolution of different biological progestins in fish and mammalian PR, as well as differences in susceptibility to environmental chemicals that disrupt PR-mediated physiology. PMID:22575083

Baker, Michael E; Uh, Kayla Y

2012-04-30

255

Segmental hair analysis after a single dose of zolpidem: comparison with a previous study.  

PubMed

Hair is a useful aid and sometimes even the only matrix in the analytical strategy in drug-facilitated crime (DFC) investigations. In this novel study, segmental hair analysis was performed after a single 10 mg dose of zolpidem was given to 20 Chinese volunteers. Hair was collected 1 month after administration and was analyzed using ultra-high-pressure liquid chromatography/electrospray ionization tandem mass spectrometry. Zolpidem concentrations were found to be in the range of 135.0-554.6 pg/mg in the proximal 0-2 cm segments. These results were markedly different from those reported by Villain et al., who used volunteers administered equal doses of zolpidem. The analytical method used, as well as the volunteers' hair color, inter-individual variations such as metabolic capacity, hair growth rate, drug incorporation rates, physical state of the hair, age, gender, body weight, etc. and diffusion from sweat or other secretions are all factors that should be considered when interpreting the DFC results. PMID:23657838

Cui, Xiaopei; Xiang, Ping; Zhang, Jingshuo; Shi, Yan; Shen, Baohua; Shen, Min

2013-05-08

256

Life-cycle cost analysis for constant-air-volume and variable-air-volume air-conditioning systems  

Microsoft Academic Search

This study presents a life-cycle cost analysis using detailed load profiles and initial and operating costs to evaluate the economic feasibilities of constant-air-volume (CAV) and variable-air-volume (VAV) air-conditioning systems. The present-worth cost method for life-cycle cost analysis is applied to a sample building located in Adana, Turkey which can be conditioned with CAV or VAV systems. In the analysis, two

Mehmet Azmi Aktacir; Orhan Büyükalaca; Tuncay Y?lmaz

2006-01-01

257

Maintenance of Strategic Models for Arms Control Analysis. Volume I. Summary Final Report.  

National Technical Information Service (NTIS)

The work under this contract is reported in eight volumes, two of which have two parts. Volume 1 discusses the following topics: Methods for arms control analysis; rapid production model (RPM); SIR NEM; peripheral programs; and, support of agency analysis...

H. R. Hesse

1974-01-01

258

Segmentation and volumetric measurement of renal cysts and parenchyma from MR images of polycystic kidneys using multi-spectral analysis method  

NASA Astrophysics Data System (ADS)

For segmentation and volume measurement of renal cysts and parenchyma from kidney MR images in subjects with autosomal dominant polycystic kidney disease (ADPKD), a semi-automated, multi-spectral anaylsis (MSA) method was developed and applied to T1- and T2-weighted MR images. In this method, renal cysts and parenchyma were characterized and segmented for their characteristic T1 and T2 signal intensity differences. The performance of the MSA segmentation method was tested on ADPKD phantoms and patients. Segmented renal cysts and parenchyma volumes were measured and compared with reference standard measurements by fluid displacement method in the phantoms and stereology and region-based thresholding methods in patients, respectively. As results, renal cysts and parenchyma were segmented successfully with the MSA method. The volume measurements obtained with MSA were in good agreement with the measurements by other segmentation methods for both phantoms and subjects. The MSA method, however, was more time-consuming than the other segmentation methods because it required pre-segmentation, image registration and tissue classification-determination steps.

Bae, K. T.; Commean, P. K.; Brunsden, B. S.; Baumgarten, D. A.; King, B. F., Jr.; Wetzel, L. H.; Kenney, P. J.; Chapman, A. B.; Torres, V. E.; Grantham, J. J.; Guay-Woodford, L. M.; Tao, C.; Miller, J. P.; Meyers, C. M.; Bennett, W. M.

2008-04-01

259

Fast segmentation and high-quality three-dimensional volume mesh creation from medical images for diffuse optical tomography  

NASA Astrophysics Data System (ADS)

Multimodal approaches that combine near-infrared (NIR) and conventional imaging modalities have been shown to improve optical parameter estimation dramatically and thus represent a prevailing trend in NIR imaging. These approaches typically involve applying anatomical templates from magnetic resonance imaging/computed tomography/ultrasound images to guide the recovery of optical parameters. However, merging these data sets using current technology requires multiple software packages, substantial expertise, significant time-commitment, and often results in unacceptably poor mesh quality for optical image reconstruction, a reality that represents a significant roadblock for translational research of multimodal NIR imaging. This work addresses these challenges directly by introducing automated digital imaging and communications in medicine image stack segmentation and a new one-click three-dimensional mesh generator optimized for multimodal NIR imaging, and combining these capabilities into a single software package (available for free download) with a streamlined workflow. Image processing time and mesh quality benchmarks were examined for four common multimodal NIR use-cases (breast, brain, pancreas, and small animal) and were compared to a commercial image processing package. Applying these tools resulted in a fivefold decrease in image processing time and 62% improvement in minimum mesh quality, in the absence of extra mesh postprocessing. These capabilities represent a significant step toward enabling translational multimodal NIR research for both expert and nonexpert users in an open-source platform.

Jermyn, Michael; Ghadyani, Hamid; Mastanduno, Michael A.; Turner, Wes; Davis, Scott C.; Dehghani, Hamid; Pogue, Brian W.

2013-08-01

260

A computer program for comprehensive ST-segment depression\\/heart rate analysis of the exercise ECG test  

Microsoft Academic Search

The ST-segment depression\\/heart rate (STHR) analysis has been found to improve the diagnostic accuracy of the exercise ECG test in detecting myocardial ischemia. Recently, three different continuous diagnostic variables based on the STHR analysis have been introduced; the STHR slope, the STHR index and the STHR hysteresis. The latter utilises both the exercise and recovery phases of the exercise ECG

Rami Lehtinen; Henri Vänttinen; Harri Sievänen; Jaakko Malmivuo

1996-01-01

261

Application of Control Volume Analysis to Cerebrospinal Fluid Dynamics  

NASA Astrophysics Data System (ADS)

Hydrocephalus is among the most common birth defects and may not be prevented nor cured. Afflicted individuals face serious issues, which at present are too complicated and not well enough understood to treat via systematic therapies. This talk outlines the framework and application of a control volume methodology to clinical Phase Contrast MRI data. Specifically, integral control volume analysis utilizes a fundamental, fluid dynamics methodology to quantify intracranial dynamics within a precise, direct, and physically meaningful framework. A chronically shunted, hydrocephalic patient in need of a revision procedure was used as an in vivo case study. Magnetic resonance velocity measurements within the patient's aqueduct were obtained in four biomedical state and were analyzed using the methods presented in this dissertation. Pressure force estimates were obtained, showing distinct differences in amplitude, phase, and waveform shape for different intracranial states within the same individual. Thoughts on the physiological and diagnostic research and development implications/opportunities will be presented.

Wei, Timothy; Cohen, Benjamin; Anor, Tomer; Madsen, Joseph

2011-11-01

262

A model-based circular binary segmentation algorithm for the analysis of array CGH data  

PubMed Central

Background Circular Binary Segmentation (CBS) is a permutation-based algorithm for array Comparative Genomic Hybridization (aCGH) data analysis. CBS accurately segments data by detecting change-points using a maximal-t test; but extensive computational burden is involved for evaluating the significance of change-points using permutations. A recent implementation utilizing a hybrid method and early stopping rules (hybrid CBS) to improve the performance in speed was subsequently proposed. However, a time analysis revealed that a major portion of computation time of the hybrid CBS was still spent on permutation. In addition, what the hybrid method provides is an approximation of the significance upper bound or lower bound, not an approximation of the significance of change-points itself. Results We developed a novel model-based algorithm, extreme-value based CBS (eCBS), which limits permutations and provides robust results without loss of accuracy. Thousands of aCGH data under null hypothesis were simulated in advance based on a variety of non-normal assumptions, and the corresponding maximal-t distribution was modeled by the Generalized Extreme Value (GEV) distribution. The modeling results, which associate characteristics of aCGH data to the GEV parameters, constitute lookup tables (eXtreme model). Using the eXtreme model, the significance of change-points could be evaluated in a constant time complexity through a table lookup process. Conclusions A novel algorithm, eCBS, was developed in this study. The current implementation of eCBS consistently outperforms the hybrid CBS 4× to 20× in computation time without loss of accuracy. Source codes, supplementary materials, supplementary figures, and supplementary tables can be found at http://ntumaps.cgm.ntu.edu.tw/eCBSsupplementary.

2011-01-01

263

Improved helicopter aeromechanical stability analysis using segmented constrained layer damping and hybrid optimization  

NASA Astrophysics Data System (ADS)

Aeromechanical stability plays a critical role in helicopter design and lead-lag damping is crucial to this design. In this paper, the use of segmented constrained damping layer (SCL) treatment and composite tailoring is investigated for improved rotor aeromechanical stability using formal optimization technique. The principal load-carrying member in the rotor blade is represented by a composite box beam, of arbitrary thickness, with surface bonded SCLs. A comprehensive theory is used to model the smart box beam. A ground resonance analysis model and an air resonance analysis model are implemented in the rotor blade built around the composite box beam with SCLs. The Pitt-Peters dynamic inflow model is used in air resonance analysis under hover condition. A hybrid optimization technique is used to investigate the optimum design of the composite box beam with surface bonded SCLs for improved damping characteristics. Parameters such as stacking sequence of the composite laminates and placement of SCLs are used as design variables. Detailed numerical studies are presented for aeromechanical stability analysis. It is shown that optimum blade design yields significant increase in rotor lead-lag regressive modal damping compared to the initial system.

Liu, Qiang; Chattopadhyay, Aditi

2000-06-01

264

Ascending Direction: East Segment Code and Milepost: 001010 114.500 0.5 Miles East of Jct I-84B (Hammett) Volumes and Percent of Daily Traffic  

Microsoft Academic Search

Hour Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day Volume % of day 0:00 200 1.4% 142 1.2% 146 1.2% 163 1.3% 168 1.2% 178 1.1% 260 1.7% 155 1.2% 230 1.5%

Sunday Monday

2009-01-01

265

Tanker Avionics/Aircrew Complement Evaluation (TAACE). Phase 0. Analysis and Mockup. Volume III. Mission Scenario.  

National Technical Information Service (NTIS)

This volume contains (1) a 'ribbon-in-the-sky' depiction of the mission scenario used during the mockup exercise, (2) a narrative overview of each mission leg, (3) a mission profile graph depicting climbs and descents during the different mission segments...

G. J. Barbato R. P. Madero G. A. Sexton R. W. Moss W. R. Brandt

1980-01-01

266

Shared genomic segment analysis: the power to find rare disease variants.  

PubMed

Shared genomic segment (SGS) analysis uses dense single nucleotide polymorphism genotyping in high-risk (HR) pedigrees to identify regions of sharing between cases. Here, we illustrate the power of SGS to identify dominant rare risk variants. Using simulated pedigrees, we consider 12 disease models based on disease prevalence, minor allele frequency and penetrance to represent disease loci that explain 0.2-99.8% of total disease risk. Pedigrees were required to contain ? 15 meioses between all cases and to be HR based on significant excess of disease (P < 0.001 or P < 0.00001). Across these scenarios, the power for a single pedigree ranged widely. Nonetheless, fewer than 10 pedigrees were sufficient for excellent power in the majority of models. Power increased with the risk attributable to the disease locus, penetrance and the excess of disease in the pedigree. Sharing allowing for one sporadic case was uniformly more powerful than sharing using all cases. Furthermore, an SGS analysis using a large attenuated familial adenomatous polyposis pedigree identified a 1.96 Mb region containing the known causal APC gene with genome-wide significance. SGS is a powerful method for detecting rare variants and a valuable complement to genome-wide association studies and linkage analysis. PMID:22989048

Knight, Stacey; Abo, Ryan P; Abel, Haley J; Neklason, Deborah W; Tuohy, Therese M; Burt, Randall W; Thomas, Alun; Camp, Nicola J

2012-09-19

267

Automatic cell segmentation and nuclear-to-cytoplasmic ratio analysis for third harmonic generated microscopy medical images.  

PubMed

Traditional biopsy procedures require invasive tissue removal from a living subject, followed by time-consuming and complicated processes, so noninvasive in vivo virtual biopsy, which possesses the ability to obtain exhaustive tissue images without removing tissues, is highly desired. Some sets of in vivo virtual biopsy images provided by healthy volunteers were processed by the proposed cell segmentation approach, which is based on the watershed-based approach and the concept of convergence index filter for automatic cell segmentation. Experimental results suggest that the proposed algorithm not only reveals high accuracy for cell segmentation but also has dramatic potential for noninvasive analysis of cell nuclear-to-cytoplasmic ratio (NC ratio), which is important in identifying or detecting early symptoms of diseases with abnormal NC ratios, such as skin cancers during clinical diagnosis via medical imaging analysis. PMID:23853298

Lee, Gwo Giun; Lin, Huan-Hsiang; Tsai, Ming-Rung; Chou, Sin-Yo; Lee, Wen-Jeng; Liao, Yi-Hua; Sun, Chi-Kuang; Chen, Chun-Fu

2013-04-01

268

Semi-automatic tool for segmentation and volumetric analysis of medical images  

Microsoft Academic Search

Segmentation software is described, developed for medical image processing and run on Windows. The software applies basic\\u000a image processing techniques through a graphical user interface. For particular applications, such as brain lesion segmentation,\\u000a the software enables the combination of different segmentation techniques to improve its efficiency. The program is applied\\u000a for magnetic resonance imaging, computed tomography and optical images of

T. Heinonen; P. Dastidar; P. Kauppinen; J. Malmivuo; H. Eskola

1998-01-01

269

Identifying Like-Minded Audiences for Global Warming Public Engagement Campaigns: An Audience Segmentation Analysis and Tool Development  

PubMed Central

Background Achieving national reductions in greenhouse gas emissions will require public support for climate and energy policies and changes in population behaviors. Audience segmentation – a process of identifying coherent groups within a population – can be used to improve the effectiveness of public engagement campaigns. Methodology/Principal Findings In Fall 2008, we conducted a nationally representative survey of American adults (n?=?2,164) to identify audience segments for global warming public engagement campaigns. By subjecting multiple measures of global warming beliefs, behaviors, policy preferences, and issue engagement to latent class analysis, we identified six distinct segments ranging in size from 7 to 33% of the population. These six segments formed a continuum, from a segment of people who were highly worried, involved and supportive of policy responses (18%), to a segment of people who were completely unconcerned and strongly opposed to policy responses (7%). Three of the segments (totaling 70%) were to varying degrees concerned about global warming and supportive of policy responses, two (totaling 18%) were unsupportive, and one was largely disengaged (12%), having paid little attention to the issue. Certain behaviors and policy preferences varied greatly across these audiences, while others did not. Using discriminant analysis, we subsequently developed 36-item and 15-item instruments that can be used to categorize respondents with 91% and 84% accuracy, respectively. Conclusions/Significance In late 2008, Americans supported a broad range of policies and personal actions to reduce global warming, although there was wide variation among the six identified audiences. To enhance the impact of campaigns, government agencies, non-profit organizations, and businesses seeking to engage the public can selectively target one or more of these audiences rather than address an undifferentiated general population. Our screening instruments are available to assist in that process.

Maibach, Edward W.; Leiserowitz, Anthony; Roser-Renouf, Connie; Mertz, C. K.

2011-01-01

270

Sequence Analysis of the Segmental Duplication Responsible for Paris Sex-Ratio Drive in Drosophila simulans  

PubMed Central

Sex-ratio distorters are X-linked selfish genetic elements that facilitate their own transmission by subverting Mendelian segregation at the expense of the Y chromosome. Naturally occurring cases of sex-linked distorters have been reported in a variety of organisms, including several species of Drosophila; they trigger genetic conflict over the sex ratio, which is an important evolutionary force. However, with a few exceptions, the causal loci are unknown. Here, we molecularly characterize the segmental duplication involved in the Paris sex-ratio system that is still evolving in natural populations of Drosophila simulans. This 37.5 kb tandem duplication spans six genes, from the second intron of the Trf2 gene (TATA box binding protein-related factor 2) to the first intron of the org-1 gene (optomotor-blind-related-gene-1). Sequence analysis showed that the duplication arose through the production of an exact copy on the template chromosome itself. We estimated this event to be less than 500 years old. We also detected specific signatures of the duplication mechanism; these support the Duplication-Dependent Strand Annealing model. The region at the junction between the two duplicated segments contains several copies of an active transposable element, Hosim1, alternating with 687 bp repeats that are noncoding but transcribed. The almost-complete sequence identity between copies made it impossible to complete the sequencing and assembly of this region. These results form the basis for the functional dissection of Paris sex-ratio drive and will be valuable for future studies designed to better understand the dynamics and the evolutionary significance of sex chromosome drive.

Fouvry, Lucie; Ogereau, David; Berger, Anne; Gavory, Frederick; Montchamp-Moreau, Catherine

2011-01-01

271

Analysis of high-identity segmental duplications in the grapevine genome  

PubMed Central

Background Segmental duplications (SDs) are blocks of genomic sequence of 1-200 kb that map to different loci in a genome and share a sequence identity > 90%. SDs show at the sequence level the same characteristics as other regions of the human genome: they contain both high-copy repeats and gene sequences. SDs play an important role in genome plasticity by creating new genes and modeling genome structure. Although data is plentiful for mammals, not much was known about the representation of SDs in plant genomes. In this regard, we performed a genome-wide analysis of high-identity SDs on the sequenced grapevine (Vitis vinifera) genome (PN40024). Results We demonstrate that recent SDs (> 94% identity and >= 10 kb in size) are a relevant component of the grapevine genome (85 Mb, 17% of the genome sequence). We detected mitochondrial and plastid DNA and genes (10% of gene annotation) in segmentally duplicated regions of the nuclear genome. In particular, the nine highest copy number genes have a copy in either or both organelle genomes. Further we showed that several duplicated genes take part in the biosynthesis of compounds involved in plant response to environmental stress. Conclusions These data show the great influence of SDs and organelle DNA transfers in modeling the Vitis vinifera nuclear DNA structure as well as the impact of SDs in contributing to the adaptive capacity of grapevine and the nutritional content of grape products through genome variation. This study represents a step forward in the full characterization of duplicated genes important for grapevine cultural needs and human health.

2011-01-01

272

Optimal analysis for segmented mirror capture and alignment in space optics system  

NASA Astrophysics Data System (ADS)

A great deal segmented mirror errors consisting of piston and tip-tilt exist when space large aperture segmented optics system deploys. These errors will result in the departure of segmented mirrors images from the view. For that, proper scanning function should be adopted to control actuators rotating the segmented mirror, so that the images of segmented mirror can be put into the view and placed in the ideal position. In my paper, the scanning functions such as screw-type, rose-type, and helianthus-type and so on are analyzed and discussed. And the optimal scanning function principle based on capturing images by the fastest velocity is put forward. After capturing, each outer segmented mirror should be brought back into alignment with the central segment. In my paper, the central and outer segments with surface errors have the different figure, a new way to control the alignment accuracy is present, which can decrease the bad effects from mirror surface and position errors effectively. As a sample, a simulation experiment is carried to study the characteristics of different scanning functions and the effects of mirror surface and position errors on alignment accuracy. In simulation experiment, the piston and tip-tilt errors scale and the ideal position of segmented mirror are given, the capture and alignment process is realized by utilizing the improved optics design software ZEMAX, the optimal scanning function and the alignment accuracy is determined.

Zhang, Xiaofang; Yu, Xin; Wang, Xia; Zhao, Lei

2008-08-01

273

Multi-Atlas Multi-Shape Segmentation of Fetal Brain MRI for Volumetric and Morphometric Analysis of Ventriculomegaly  

PubMed Central

The recent development of motion robust super-resolution fetal brain MRI holds out the potential for dramatic new advances in volumetric and morphometric analysis. Volumetric analysis based on volumetric and morphometric biomarkers of the developing fetal brain must include segmentation. Automatic segmentation of fetal brain MRI is challenging, however, due to the highly variable size and shape of the developing brain; possible structural abnormalities; and the relatively poor resolution of fetal MRI scans. To overcome these limitations, we present a novel, constrained, multi-atlas, multi-shape automatic segmentation method that specifically addresses the challenge of segmenting multiple structures with similar intensity values in subjects with strong anatomic variability. Accordingly, we have applied this method to shape segmentation of normal, dilated, or fused lateral ventricles for quantitative analysis of ventriculomegaly (VM), which is a pivotal finding in the earliest stages of fetal brain development, and warrants further investigation. Utilizing these innovative techniques, we introduce novel volumetric and morphometric biomarkers of VM comparing these values to those that are generated by standard methods of VM analysis, i.e., by measuring the ventricular atrial diameter (AD) on manually selected sections of 2D ultrasound or 2D MRI. To this end, we studied 25 normal and abnormal fetuses in the gestation age (GA) range of 19 to 39 weeks (mean=28.26, stdev=6.56). This heterogenous dataset was essentially used to 1) validate our segmentation method for normal and abnormal ventricles; and 2) show that the proposed biomarkers may provide improved detection of VM as compared to the AD measurement.

Gholipour, Ali; Akhondi-Asl, Alireza; Estroff, Judy A.; Warfield, Simon K.

2012-01-01

274

Motion analysis of knee joint using dynamic volume images  

NASA Astrophysics Data System (ADS)

Acquisition and analysis of three-dimensional movement of knee joint is desired in orthopedic surgery. We have developed two methods to obtain dynamic volume images of knee joint. One is a 2D/3D registration method combining a bi-plane dynamic X-ray fluoroscopy and a static three-dimensional CT, the other is a method using so-called 4D-CT that uses a cone-beam and a wide 2D detector. In this paper, we present two analyses of knee joint movement obtained by these methods: (1) transition of the nearest points between femur and tibia (2) principal component analysis (PCA) of six parameters representing the three dimensional movement of knee. As a preprocessing for the analysis, at first the femur and tibia regions are extracted from volume data at each time frame and then the registration of the tibia between different frames by an affine transformation consisting of rotation and translation are performed. The same transformation is applied femur as well. Using those image data, the movement of femur relative to tibia can be analyzed. Six movement parameters of femur consisting of three translation parameters and three rotation parameters are obtained from those images. In the analysis (1), axis of each bone is first found and then the flexion angle of the knee joint is calculated. For each flexion angle, the minimum distance between femur and tibia and the location giving the minimum distance are found in both lateral condyle and medial condyle. As a result, it was observed that the movement of lateral condyle is larger than medial condyle. In the analysis (2), it was found that the movement of the knee can be represented by the first three principal components with precision of 99.58% and those three components seem to strongly relate to three major movements of femur in the knee bend known in orthopedic surgery.

Haneishi, Hideaki; Kohno, Takahiro; Suzuki, Masahiko; Moriya, Hideshige; Mori, Sin-ichiro; Endo, Masahiro

2006-03-01

275

Semisupervised segmentation of MRI stroke studies  

NASA Astrophysics Data System (ADS)

Fast, accurate, and reproducible image segmentation is vital to the diagnosis, treatment, and evaluation of many medical situations. We present development and application of a semi-supervised method for segmenting normal and abnormal brain tissues from magnetic resonance images (MRI) of stroke patients. The method does not require manual drawing of the tissue boundaries. It is therefore faster and more reproducible than conventional methods. The steps of the new method are as follows: (1) T2- and T1-weighted MR images are co-registered using a head and hat approach. (2) Intracranial brain volume is segmented from the skull, scalp, and background using a multi-resolution edge tracking algorithm. (3) Additive noise is suppressed (image is restored) using a non-linear edge-preserving filter which preserves partial volume information on average. (4) Image nonuniformities are corrected using a modified lowpass filtering approach. (5) The resulting images are segmented using a self organizing data analysis technique which is similar in principle to the K-means clustering but includes a set of additional heuristic merging and splitting procedures to generate a meaningful segmentation. (6) Segmented regions are labeled white matter, gray matter, CSF, partial volumes of normal tissues, zones of stroke, or partial volumes between stroke and normal tissues. (7) Previous steps are repeated for each slice of the brain and the volume of each tissue type is estimated from the results. Details and significance of each step are explained. Experimental results using a simulation, a phantom, and selected clinical cases are presented.

Soltanian-Zadeh, Hamid; Windham, Joe P.; Robbins, Linda

1997-04-01

276

A Comparison of the Segmental Analysis of Sodium Reabsorption during Ringer's and Hyperoncotic Albumin Infusion in the Rat  

PubMed Central

Studies were designed to compare the segmental analysis of sodium reabsorption along the nephron during volume expansion with either 10% body weight Ringer's or 0.6% body weight hyperoncotic albumin. Total kidney and nephron glomerular filtration rate increased similarly with both, but urinary sodium excretion (12.7 vs. 4.0 ?eq/min, P < 0.001) and fractional sodium excretion (5.0 vs. 1.6%, P < 0.001) increased to a greater extent with Ringer's. Fractional reabsorption of sodium in the proximal tubule was diminished in both groups but to a significantly greater extent during Ringer's (P < 0.005). Absolute reabsorption was inhibited only in the Ringer's group. Delivery of filtrate out of the proximal tubule was greater in the Ringer's studies, 45 vs. 37 nl/min (P < 0.001). However, both fractional and absolute sodium delivery to the early and late distal tubule were not significantly different in the two groups. Fractional reabsorption in the collecting duct decreased from 96% in hydropenia to 31% during Ringer's but fell only slightly to 80% in the albumin studies. Absolute collecting duct reabsorption was also greater in the albumin studies, 0.55 vs. 0.21 neq/min (P < 0.001), which could totally account for the difference in urinary sodium excretion between the two groups. 22Na recovery in the final urine after end distal microinjections was 71% during Ringer's infusion and 34% during albumin (P < 0.001). From these data we conclude that: (a) Ringer's solution has a greater inhibitory effect on proximal tubular sodium reabsorption, and (b) in spite of this effect, differences in mucosal to serosal collecting duct sodium transport are primarily responsible for the greater natriuresis during Ringer's infusion.

Stein, Jay H.; Osgood, Richard W.; Boonjarern, Sampanta; Ferris, Thomas F.

1973-01-01

277

Segment Optimization and Data-Driven Thresholding for Knowledge-Based Landslide Detection by Object-Based Image Analysis  

Microsoft Academic Search

To detect landslides by object-based image analysis using criteria based on shape, color, texture, and, in particular, contextual information and process knowledge, candidate seg- ments must be delineated properly. This has proved challenging in the past, since segments are mainly created using spectral and size criteria that are not consistent for landslides. This paper presents an approach to select objectively

Tapas Ranjan Martha; Norman Kerle; Cees J. van Westen; Victor Jetten; K. Vinod Kumar

2011-01-01

278

Competitive Analyses between Regional Malls and Big-box Retailers: A Correspondence Analysis for Segmentation and Positioning  

Microsoft Academic Search

† and Soo-Hee Park †† This study compares demographic composition and retail attributes for four competing retailer formats: (a) regional malls, (b) supercenters, (c) category killers, and (d) warehouse clubs. A total of 569 consumers, from four geographically dispersed metropolitan areas, responded to Computer Assisted Telephone Interviews. A correspondence analysis was used to segment consumer groups based upon two demographic

Min-Young Lee; Kelly Green Atkins; Youn-Kyung Kim

279

Automated condition-invariable neurite segmentation and synapse classification using textural analysis-based machine-learning algorithms.  

PubMed

High-resolution live-cell imaging studies of neuronal structure and function are characterized by large variability in image acquisition conditions due to background and sample variations as well as low signal-to-noise ratio. The lack of automated image analysis tools that can be generalized for varying image acquisition conditions represents one of the main challenges in the field of biomedical image analysis. Specifically, segmentation of the axonal/dendritic arborizations in brightfield or fluorescence imaging studies is extremely labor-intensive and still performed mostly manually. Here we describe a fully automated machine-learning approach based on textural analysis algorithms for segmenting neuronal arborizations in high-resolution brightfield images of live cultured neurons. We compare performance of our algorithm to manual segmentation and show that it combines 90% accuracy, with similarly high levels of specificity and sensitivity. Moreover, the algorithm maintains high performance levels under a wide range of image acquisition conditions indicating that it is largely condition-invariable. We further describe an application of this algorithm to fully automated synapse localization and classification in fluorescence imaging studies based on synaptic activity. Textural analysis-based machine-learning approach thus offers a high performance condition-invariable tool for automated neurite segmentation. PMID:23261652

Kandaswamy, Umasankar; Rotman, Ziv; Watt, Dana; Schillebeeckx, Ian; Cavalli, Valeria; Klyachko, Vitaly A

2012-12-20

280

Knowledge-based method for segmentation and analysis of lung boundaries in chest X-ray images  

Microsoft Academic Search

We present a knowledge-based approach to segmentation and analysis of the lung boundaries in chest X-rays. Image edges are matched to an anatomical model of the lung boundary using parametric features. A modular system architecture was developed which incorporates the model, image processing routines, an inference engine and a blackboard. Edges associated with the lung boundary are automatically identified and

Matthew S. Brown; Laurence S. Wilson; Bruce D. Doust; Robert W. Gill; Changming Sun

281

Impact of BAC limit reduction on different population segments: a Poisson fixed effect analysis.  

PubMed

Over the past few decades, several countries enacted the reduction of the legal blood alcohol concentration (BAC) limit, often alongside the administrative license revocation or suspension, to battle drinking-and-driving behavior. Several researchers investigated the effectiveness of these policies by applying different analysis procedures, while assuming population homogeneity in responding to these laws. The present analysis focuses on the evaluation of the impact of BAC limit reduction on different population segments. Poisson regression models, adapted to account for possible observation dependence over time and state specific effects, are estimated to measure the reduction of the number of alcohol-related accidents and fatalities for single-vehicle accidents in 22 U.S. jurisdictions over a period of 15 years starting in 1990. Model estimates demonstrate that, for alcohol-related single-vehicle crashes, (i) BAC laws are more effective in terms of reduction of number of casualties rather than number of accidents, (ii) women and elderly population exhibit higher law compliance with respect to men and to young adult and adult population, respectively, and (iii) the presence of passengers in the vehicle enhances the sense of responsibility of the driver. PMID:17920837

Kaplan, Sigal; Prato, Carlo Giacomo

2007-03-26

282

A comparison between handgrip strength, upper limb fat free mass by segmental bioelectrical impedance analysis (SBIA) and anthropometric measurements in young males  

NASA Astrophysics Data System (ADS)

The mechanical function and size of a muscle may be closely linked. Handgrip strength (HGS) has been used as a predictor of functional performing. Anthropometric measurements have been made to estimate arm muscle area (AMA) and physical muscle mass volume of upper limb (ULMMV). Electrical volume estimation is possible by segmental BIA measurements of fat free mass (SBIA-FFM), mainly muscle-mass. Relationship among these variables is not well established. We aimed to determine if physical and electrical muscle mass estimations relate to each other and to what extent HGS is to be related to its size measured by both methods in normal or overweight young males. Regression analysis was used to determine association between these variables. Subjects showed a decreased HGS (65.5%), FFM, (85.5%) and AMA (74.5%). It was found an acceptable association between SBIA-FFM and AMA (r2 = 0.60) and poorer between physical and electrical volume (r2 = 0.55). However, a paired Student t-test and Bland and Altman plot showed that physical and electrical models were not interchangeable (pt<0.0001). HGS showed a very weak association with anthropometric (r2 = 0.07) and electrical (r2 = 0.192) ULMMV showing that muscle mass quantity does not mean muscle strength. Other factors influencing HGS like physical training or nutrition require more research.

Gonzalez-Correa, C. H.; Caicedo-Eraso, J. C.; Varon-Serna, D. R.

2013-04-01

283

Feature analysis and centromere segmentation of human chromosome images using an iterative fuzzy algorithm  

Microsoft Academic Search

Classification of homologous chromosomes is essential to advanced studies of cancer genetics. Centromere intensities are believed to be an important differentiating feature between homologs. Therefore, segmentation of centromeres is a major step toward the realization of homolog classification. This paper describes an iterative fuzzy algorithm which successfully segments centromeres from images of human chromosomes prepared using fluorescence in-situ hybridization technique.

Parvin Mousavi; Rabab Kreidieh Ward; Sidney S. Fels; Mohammad Sameti; Peter M. Lansdorp

2002-01-01

284

Multi-Feature Analysis and Classification of Human Chromosome Images Using Centromere Segmentation Algorithms  

Microsoft Academic Search

Classification of homologous human chromosomes is essential to advanced studies of cancer genetics. This paper describes novel segmentation and classification algorithms to extract multiple features, from microscopy images of chromosomes, for classification purposes. Multicolour images of metaphase chromosomes prepared by applying PNA probes are used for this purpose. Centromeres are segmented using an iterative fuzzy algorithm as well as a

Parvin Mousavi; Rabab Kreidieh Ward; Peter M. Lansdorp; Sidney Fels

2000-01-01

285

Market Segmentation Analysis Using Attitudes Toward Transportation: Exploring the Differences Between Men and Women  

Microsoft Academic Search

Traveler attitudes and preferences as well as demographic variables are important components of travel behavior. By using travel attitudes, factor and cluster analyses were conducted to segment the sample. Six distinct groups were extracted: transit enthusiasts, anxious status seekers, carless riders, green cruisers, frugal travelers, and obstinate drivers. The segments showed unique combinations of attitudes with distinct travel behaviors and

Gabriela Beirao; Jose Sarsfield Cabral

2008-01-01

286

Functional Analysis of the Noncoding Regions of the Uukuniemi Virus (Bunyaviridae) RNA Segments  

Microsoft Academic Search

The role of the variable portion of the noncoding regions (NCRs) of the three Bunyaviridae RNA segments (L, M, S) in transcription, replication, and packaging was studied using the recently developed plasmid-driven RNA polymerase I minigenome system for Uukuniemi (UUK) virus, genus Phlebovirus (11), as a model. Comparison of the different segments showed that all NCRs were sufficient to mediate

Kirsten Flick; Anna Katz; Anna Overby; Heinz Feldmann; Ralf F. Pettersson; Ramon Flick

2004-01-01

287

A Theoretical Analysis of How Segmentation of Dynamic Visualizations Optimizes Students' Learning  

ERIC Educational Resources Information Center

|This article reviews studies investigating segmentation of dynamic visualizations (i.e., showing dynamic visualizations in pieces with pauses in between) and discusses two not mutually exclusive processes that might underlie the effectiveness of segmentation. First, cognitive activities needed for dealing with the transience of dynamic…

Spanjers, Ingrid A. E.; van Gog, Tamara; van Merrienboer, Jeroen J. G.

2010-01-01

288

A Unified Set of Analysis Tools for Uterine Cervix Image Segmentation  

PubMed Central

Segmentation is a fundamental component of many medical image processing applications, and it has long been recognized as a challenging problem. In this paper, we report our research and development efforts on analyzing and extracting clinically meaningful regions from uterine cervix images in a large database created for the study of cervical cancer. In addition to proposing new algorithms, we also focus on developing open source tools which are in synchrony with the research objectives. These efforts have resulted in three Web-accessible tools which address three important and interrelated sub-topics in medical image segmentation, respectively: the BMT (Boundary Marking Tool), CST (Cervigram Segmentation Tool), and MOSES (Multi-Observer Segmentation Evaluation System). The BMT is for manual segmentation, typically to collect “ground truth” image regions from medical experts. The CST is for automatic segmentation, and MOSES is for segmentation evaluation. These tools are designed to be a unified set in which data can be conveniently exchanged. They have value not only for improving the reliability and accuracy of algorithms of uterine cervix image segmentation, but also promoting collaboration between biomedical experts and engineers which are crucial to medical image processing applications. Although the CST is designed for the unique characteristics of cervigrams, the BMT and MOSES are very general and extensible, and can be easily adapted to other biomedical image collections.

Xue, Zhiyun; Long, Rodney; Antani, Sameer; Neve, Leif; Zhu, Yaoyao; Thoma, George

2010-01-01

289

White blood cell segmentation using morphological operators and scale-space analysis  

Microsoft Academic Search

Abstract Cell segmentation is a challenging problem due to both the complex nature of the cells and the uncertainty present in video microscopy. Manual methods for this purpose are onerous, imprecise and highly subjective, thus requiring automated methods that perform this task in an objective and efficient way. In this paper, we propose a novel method to segment nucleus and

Leyza Baldo Dorini; Rodrigo Minetto; Neucimar Jerônimo Leite

2007-01-01

290

Sequence determination and phylogenetic analysis of the Akabane bunyavirus S RNA genome segment  

Microsoft Academic Search

The nucleotide sequence of the small (S) RNA segment of Akabane (AKA) bunyavirus was de- termined. The segment is 858 nucleotides long and contains two overlapping open reading frames (ORFs), which encode the nucleocapsid (N) and nonstructural (NSs) proteins, consistent with other bunyaviruses. Comparisons with the Aino virus S RNA sequence indicated that there is 73-5% ident- ity in nucleotide

Hiroomi Akashi; Yoshihiro Kaku; Xiang-Gang Kong; Hai Pang

1997-01-01

291

Model-based segmentation and motion analysis of the thoracic aorta from 4D ECG-gated CTA images.  

PubMed

Pathologies of the thoracic aorta can alter the shape and motion pattern of the aorta throughout the cardiac cycle. For diagnosis and therapy planning, determination of the aortic shape and motion is important. We introduce a new approach for segmentation and motion analysis of the thoracic aorta from 4D ECG-CTA images, which combines spatial and temporal tracking, motion determination by intensity-based matching, and 3D fitting of vessel models. The approach has been successfully applied to 30 clinically relevant 4D CTA image sequences. We have also performed a quantitative evaluation of the segmentation accuracy. PMID:22003666

Biesdorf, Andreas; Wörz, Stefan; Müller, Tobias; Weber, Tim Frederik; Heye, Tobias; Hosch, Waldemar; von Tengg-Kobligk, Hendrik; Rohr, Karl

2011-01-01

292

Interactive 3D segmentation of the prostate in magnetic resonance images using shape and local appearance similarity analysis  

NASA Astrophysics Data System (ADS)

3D segmentation of the prostate in medical images is useful to prostate cancer diagnosis and therapy guidance, but is time-consuming to perform manually. Clinical translation of computer-assisted segmentation algorithms for this purpose requires a comprehensive and complementary set of evaluation metrics that are informative to the clinical end user. We have developed an interactive 3D prostate segmentation method for 1.5T and 3.0T T2-weighted magnetic resonance imaging (T2W MRI) acquired using an endorectal coil. We evaluated our method against manual segmentations of 36 3D images using complementary boundary-based (mean absolute distance; MAD), regional overlap (Dice similarity coefficient; DSC) and volume difference (?V) metrics. Our technique is based on inter-subject prostate shape and local boundary appearance similarity. In the training phase, we calculated a point distribution model (PDM) and a set of local mean intensity patches centered on the prostate border to capture shape and appearance variability. To segment an unseen image, we defined a set of rays - one corresponding to each of the mean intensity patches computed in training - emanating from the prostate centre. We used a radial-based search strategy and translated each mean intensity patch along its corresponding ray, selecting as a candidate the boundary point with the highest normalized cross correlation along each ray. These boundary points were then regularized using the PDM. For the whole gland, we measured a mean+/-std MAD of 2.5+/-0.7 mm, DSC of 80+/-4%, and ?V of 1.1+/-8.8 cc. We also provided an anatomic breakdown of these metrics within the prostatic base, mid-gland, and apex.

Shahedi, Maysam; Fenster, Aaron; Cool, Derek W.; Romagnoli, Cesare; Ward, Aaron D.

2013-03-01

293

Automated segmentation and fractal analysis of high-resolution non-invasive capillary perfusion maps of the human retina.  

PubMed

The retina provides a window to study the pathophysiology of cerebrovascular diseases. Pathological retinal microvascular changes may reflect microangiopathic processes in the brain. Recent advances in optical imaging techniques have enabled the imaging of the retinal microvasculature at the capillary level, and the generation of high-resolution, non-invasive capillary perfusion maps (nCPMs) with the Retinal Function Imager (RFI). However, the lack of quantitative analyses of the nCPMs may limit the wider application of the method in clinical research. The goal of this project was to demonstrate the feasibility of automated segmentation and fractal analysis of nCPMs. We took two nCPMs of each subject in a group of 6 healthy volunteers and used our segmentation algorithm to do the automated segmentation for monofractal and multifractal analyses. The monofractal dimension was 1.885±0.020, and the multifractal dimension was 1.876±0.010 (P=0.108). The coefficient of repeatability was 0.070 for monofractal analysis and 0.026 for multifractal analysis. This study demonstrated that the automatic segmentation of nCPMs is feasible for fractal analyses. Both monofractal and multifractal analyses yielded similar results. The quantitative analyses of microvasculature at the capillary level may open up a new era for studying microvascular diseases such as cerebral small vessel disease. PMID:23806780

Jiang, Hong; Debuc, Delia Cabrera; Rundek, Tatjana; Lam, Byron L; Wright, Clinton B; Shen, Meixiao; Tao, Aizhu; Wang, Jianhua

2013-06-24

294

Three-dimensional volume analysis of vasculature in engineered tissues  

NASA Astrophysics Data System (ADS)

Three-dimensional textural and volumetric image analysis holds great potential in understanding the image data produced by multi-photon microscopy. In this paper, an algorithm that quantitatively analyzes the texture and the morphology of vasculature in engineered tissues is proposed. The investigated 3D artificial tissues consist of Human Umbilical Vein Endothelial Cells (HUVEC) embedded in collagen exposed to two regimes of ultrasound standing wave fields under different pressure conditions. Textural features were evaluated using the normalized Gray-Scale Cooccurrence Matrix (GLCM) combined with Gray-Level Run Length Matrix (GLRLM) analysis. To minimize error resulting from any possible volume rotation and to provide a comprehensive textural analysis, an averaged version of nine GLCM and GLRLM orientations is used. To evaluate volumetric features, an automatic threshold using the gray level mean value is utilized. Results show that our analysis is able to differentiate among the exposed samples, due to morphological changes induced by the standing wave fields. Furthermore, we demonstrate that providing more textural parameters than what is currently being reported in the literature, enhances the quantitative understanding of the heterogeneity of artificial tissues.

YousefHussien, Mohammed; Garvin, Kelley; Dalecki, Diane; Saber, Eli; Helguera, María.

2013-01-01

295

Structural and Functional Analysis of Transmembrane Segment IV of the Salt Tolerance Protein Sod2.  

PubMed

Sod2 is the plasma membrane Na(+)/H(+) exchanger of the fission yeast Schizosaccharomyces pombe. It provides salt tolerance by removing excess intracellular sodium (or lithium) in exchange for protons. We examined the role of amino acid residues of transmembrane segment IV (TM IV) ((126)FPQINFLGSLLIAGCITSTDPVLSALI(152)) in activity by using alanine scanning mutagenesis and examining salt tolerance in sod2-deficient S. pombe. Two amino acids were critical for function. Mutations T144A and V147A resulted in defective proteins that did not confer salt tolerance when reintroduced into S. pombe. Sod2 protein with other alanine mutations in TM IV had little or no effect. T144D and T144K mutant proteins were inactive; however, a T144S protein was functional and provided lithium, but not sodium, tolerance and transport. Analysis of sensitivity to trypsin indicated that the mutations caused a conformational change in the Sod2 protein. We expressed and purified TM IV (amino acids 125-154). NMR analysis yielded a model with two helical regions (amino acids 128-142 and 147-154) separated by an unwound region (amino acids 143-146). Molecular modeling of the entire Sod2 protein suggested that TM IV has a structure similar to that deduced by NMR analysis and an overall structure similar to that of Escherichia coli NhaA. TM IV of Sod2 has similarities to TM V of the Zygosaccharomyces rouxii Na(+)/H(+) exchanger and TM VI of isoform 1 of mammalian Na(+)/H(+) exchanger. TM IV of Sod2 is critical to transport and may be involved in cation binding or conformational changes of the protein. PMID:23836910

Ullah, Asad; Kemp, Grant; Lee, Brian; Alves, Claudia; Young, Howard; Sykes, Brian D; Fliegel, Larry

2013-07-08

296

Combined Market Structure and Segmentation Analysis Based on Brand Choice Data: Overcoming the Limitations of Conventional Techniques with Topologically Ordered Feature Maps  

Microsoft Academic Search

: The objective and related issues of simultaneously performing competitive marketstructure (CMS) and market segmentation analysis is well-documented in the marketingliterature. In this paper, an artificial neural network based approach of Kohonen (1982) for theformation of topological ordered feature maps is introduced into the context of brand choicedata based combined CMS\\/segmentation analysis. Selected aspects of the methodologicalbasis are discussed and

Thomas Reutterer

1998-01-01

297

Magnetic field analysis of Lorentz motors using a novel segmented magnetic equivalent circuit method.  

PubMed

A simple and accurate method based on the magnetic equivalent circuit (MEC) model is proposed in this paper to predict magnetic flux density (MFD) distribution of the air-gap in a Lorentz motor (LM). In conventional MEC methods, the permanent magnet (PM) is treated as one common source and all branches of MEC are coupled together to become a MEC network. In our proposed method, every PM flux source is divided into three sub-sections (the outer, the middle and the inner). Thus, the MEC of LM is divided correspondingly into three independent sub-loops. As the size of the middle sub-MEC is small enough, it can be treated as an ideal MEC and solved accurately. Combining with decoupled analysis of outer and inner MECs, MFD distribution in the air-gap can be approximated by a quadratic curve, and the complex calculation of reluctances in MECs can be avoided. The segmented magnetic equivalent circuit (SMEC) method is used to analyze a LM, and its effectiveness is demonstrated by comparison with FEA, conventional MEC and experimental results. PMID:23358368

Qian, Junbing; Chen, Xuedong; Chen, Han; Zeng, Lizhan; Li, Xiaoqing

2013-01-28

298

Magnetic Field Analysis of Lorentz Motors Using a Novel Segmented Magnetic Equivalent Circuit Method  

PubMed Central

A simple and accurate method based on the magnetic equivalent circuit (MEC) model is proposed in this paper to predict magnetic flux density (MFD) distribution of the air-gap in a Lorentz motor (LM). In conventional MEC methods, the permanent magnet (PM) is treated as one common source and all branches of MEC are coupled together to become a MEC network. In our proposed method, every PM flux source is divided into three sub-sections (the outer, the middle and the inner). Thus, the MEC of LM is divided correspondingly into three independent sub-loops. As the size of the middle sub-MEC is small enough, it can be treated as an ideal MEC and solved accurately. Combining with decoupled analysis of outer and inner MECs, MFD distribution in the air-gap can be approximated by a quadratic curve, and the complex calculation of reluctances in MECs can be avoided. The segmented magnetic equivalent circuit (SMEC) method is used to analyze a LM, and its effectiveness is demonstrated by comparison with FEA, conventional MEC and experimental results.

Qian, Junbing; Chen, Xuedong; Chen, Han; Zeng, Lizhan; Li, Xiaoqing

2013-01-01

299

[Image post-processing, part 1: visualization and segmentation].  

PubMed

Image post-processing of large thin-slice radiological datasets relies on increasingly diverse and complex algorithms. Basic techniques of visualization, segmentation and data analysis will be presented in this article focusing on methods which are integrated into the majority of current viewing and reporting tools, such as multiplanar reformation, volume rendering or basic segmentation. Subsequently, more complex methods and a possible role of post-processing algorithms in the radiology of the future will be discussed. PMID:23754573

Baumann, T; Langer, M

2013-09-01

300

Finite element analysis of weightbath hydrotraction treatment of degenerated lumbar spine segments in elastic phase.  

PubMed

3D finite element models of human lumbar functional spinal units (FSU) were used for numerical analysis of weightbath hydrotraction therapy (WHT) applied for treating degenerative diseases of the lumbar spine. Five grades of age-related degeneration were modeled by material properties. Tensile material parameters of discs were obtained by parameter identification based on in vivo measured elongations of lumbar segments during regular WHT, compressive material constants were obtained from the literature. It has been proved numerically that young adults of 40-45 years have the most deformable and vulnerable discs, while the stability of segments increases with further aging. The reasons were found by analyzing the separated contrasting effects of decreasing incompressibility and increasing hardening of nucleus, yielding non-monotonous functions of stresses and deformations in terms of aging and degeneration. WHT consists of indirect and direct traction phases. Discs show a bilinear material behaviour with higher resistance in indirect and smaller in direct traction phase. Consequently, although the direct traction load is only 6% of the indirect one, direct traction deformations are 15-90% of the indirect ones, depending on the grade of degeneration. Moreover, the ratio of direct stress relaxation remains equally about 6-8% only. Consequently, direct traction controlled by extra lead weights influences mostly the deformations being responsible for the nerve release; while the stress relaxation is influenced mainly by the indirect traction load coming from the removal of the compressive body weight and muscle forces in the water. A mildly degenerated disc in WHT shows 0.15mm direct, 0.45mm indirect and 0.6mm total extension; 0.2mm direct, 0.6mm indirect and 0.8mm total posterior contraction. A severely degenerated disc exhibits 0.05mm direct, 0.05mm indirect and 0.1mm total extension; 0.05mm direct, 0.25mm indirect and 0.3mm total posterior contraction. These deformations are related to the instant elastic phase of WHT that are doubled during the creep period of the treatment. The beneficial clinical impacts of WHT are still evident even 3 months later. PMID:19883918

Kurutz, M; Oroszváry, L

2009-11-01

301

Cost-Benefit Analysis for Inland Navigation Improvements. Volume 1.  

National Technical Information Service (NTIS)

Research is directed towards improvement in procedures for the estimation of that portion of inland waterway transportation benefits which contribute to national income. The report is in three volumes. The first volume develops a conceptual framework whic...

J. P. Stucker L. B. Lave L. N. Moses M. V. Beuthe W. B. Allen

1970-01-01

302

Cost - Benefit Analysis for Inland Navigation Improvements. Volume 2.  

National Technical Information Service (NTIS)

Research is directed towards improvement in procedures for the estimation of that portion of inland waterway transportation benefits which contribute to national income. The report is in three volumes. The second volume deals with the development of deman...

J. P. Stucker L. B. Lave L. N. Moses M. V. Beuthe W. B. Allen

1970-01-01

303

Nucleotide sequence analysis of the large (L) genomic RNA segment of Bunyamwera virus, the prototype of the family Bunyaviridae.  

PubMed

The complete nucleotide sequence of the large (L) genome segment of Bunyamwera virus has been determined from overlapping cDNA clones. The segment is 6875 nucleotides long and has a base composition of 29.8% A, 17.9% C, 15.4% G, and 36.9% U. Eighteen of the terminal 19 nucleotides at the 3' and 5' ends are complementary. In the viral-complementary (+ sense) RNA there is a single long open reading frame (ORF) from AUG at bases 51-53 to a UAG stop codon at bases 6765-6767; this ORF encodes a polypeptide of 2238 amino acids (MW 259,000), corresponding to the L protein which has been mapped to the L RNA segment by analysis of reassortants of Bunyamwera, Batai, and Maguari viruses. The amino-terminal 46 amino acids of the L protein show strong homology (63% identity) with the amino-termini of ORFs predicted from limited sequence analysis of the L segments of La Crosse and snowshoe hare bunyaviruses. Comparison with the polymerase proteins encoded by other negative-strand viruses showed weak homology with part of the influenza virus PB1 protein, but no homology was detected with the other influenza virus polymerase proteins nor with the L proteins of arenaviruses, paramyxoviruses, and rhabdoviruses. At the 5' end of genomic (- sense) RNA there is an AUG-initiated ORF potentially encoding a protein of 14,700; the significance of this ORF is unknown at present. PMID:2596023

Elliott, R M

1989-12-01

304

An Entropy-Based Automated Cell Nuclei Segmentation and Quantification: Application in Analysis of Wound Healing Process  

PubMed Central

The segmentation and quantification of cell nuclei are two very significant tasks in the analysis of histological images. Accurate results of cell nuclei segmentation are often adapted to a variety of applications such as the detection of cancerous cell nuclei and the observation of overlapping cellular events occurring during wound healing process in the human body. In this paper, an automated entropy-based thresholding system for segmentation and quantification of cell nuclei from histologically stained images has been presented. The proposed translational computation system aims to integrate clinical insight and computational analysis by identifying and segmenting objects of interest within histological images. Objects of interest and background regions are automatically distinguished by dynamically determining 3 optimal threshold values for the 3 color components of an input image. The threshold values are determined by means of entropy computations that are based on probability distributions of the color intensities of pixels and the spatial similarity of pixel intensities within neighborhoods. The effectiveness of the proposed system was tested over 21 histologically stained images containing approximately 1800 cell nuclei, and the overall performance of the algorithm was found to be promising, with high accuracy and precision values.

Oswal, Varun; Belle, Ashwin; Diegelmann, Robert; Najarian, Kayvan

2013-01-01

305

An entropy-based automated cell nuclei segmentation and quantification: application in analysis of wound healing process.  

PubMed

The segmentation and quantification of cell nuclei are two very significant tasks in the analysis of histological images. Accurate results of cell nuclei segmentation are often adapted to a variety of applications such as the detection of cancerous cell nuclei and the observation of overlapping cellular events occurring during wound healing process in the human body. In this paper, an automated entropy-based thresholding system for segmentation and quantification of cell nuclei from histologically stained images has been presented. The proposed translational computation system aims to integrate clinical insight and computational analysis by identifying and segmenting objects of interest within histological images. Objects of interest and background regions are automatically distinguished by dynamically determining 3 optimal threshold values for the 3 color components of an input image. The threshold values are determined by means of entropy computations that are based on probability distributions of the color intensities of pixels and the spatial similarity of pixel intensities within neighborhoods. The effectiveness of the proposed system was tested over 21 histologically stained images containing approximately 1800 cell nuclei, and the overall performance of the algorithm was found to be promising, with high accuracy and precision values. PMID:23533544

Oswal, Varun; Belle, Ashwin; Diegelmann, Robert; Najarian, Kayvan

2013-03-05

306

Conformational analysis of peptide analogues of silkmoth chorion protein segments using CD, NMR and molecular modelling.  

PubMed

Silkmoth proteins secreted from the follicular cells that surround the oocyte form a large extracellular assembly which is important for protecting and sustaining the structure of the oocyte and the developing embryo. These proteins have been classified into two major families (A and B). Sequence analysis showed conservation of a central domain containing long stretches of six amino acid residue repeats in both families, which have been suggested to be organized in beta-sheet structures. In this work NMR and CD spectra, as well as molecular calculations, have been used to investigate the conformational properties of two synthetic peptides (A and B), analogues of parts of the central domain of silkmoth chorion proteins of the A and B families, respectively. These peptides consist of three tandem repeats of the six-residue basic motif. Analysis of CD spectra of the two peptides in aqueous solutions and mixtures with organic solvents revealed beta-sheet and turn structural elements with a percentage higher than 40%. NOESY spectra at low temperatures (263-273 K) show sequential nOe connectivities (i, i + 1), indicative of a relative flexibility. The presence of HNi-HNi+1 cross-peaks and medium Halphai-HNi+1 connectivities, chemical shift deviations and temperature coefficient data provide, for the first time, experimental evidence that local folded structures around Gly residues occur in peptide segments of chorion proteins in solution. Simulated annealing calculations were used to examine the conformational space of the peptides and to probe the initial steps of amyloid fibril formation in the case of chorion proteins. PMID:15214442

Benaki, Dimitra C; Mikros, Emmanuel; Hamodrakas, Stavros J

2004-06-01

307

Economic Analysis of Potential Effluent Guidelines for Selected Segments of the Fish Hatchery and Farm Industry.  

National Technical Information Service (NTIS)

The report analyzes the economic impact of the effluent control guidelines proposed by the Environmental Protection Agency on selected segments of the fish hatchery and fish farm industries, on specifically two four-digit SIC code industries: SIC 0921, Fi...

1976-01-01

308

Identifying fault segments from 3D fault drag analysis (Vienna Basin, Austria)  

NASA Astrophysics Data System (ADS)

The segmented growth of the Markgrafneusiedl normal fault in the late Miocene clastic sediments of the central Vienna Basin (Austria) was investigated by construction of a detailed three-dimensional (3D) structural model. Using high resolution 3D seismic data, the fault surface and marker horizons in the hanging wall and the footwall of the Markgrafneusiedl Fault were mapped and orientation, displacement and morphology of the fault surface were quantified. Individual, fault segments were identified by direct mapping of the deflection of the marker horizons close to the fault surface. Correlating the size of the identified segments with the magnitude of fault drag and displacement distribution showed that fault evolution progressed in several stages. The proposed method allows the detection of segments that are not recorded by the magnitude of displacement or fault morphology. Most importantly, detailed mapping of marker deflections in the hanging wall could help to constrain equivalent structures in the footwall, which may represent potential hydrocarbon traps.

Spahi?, Darko; Grasemann, Bernhard; Exner, Ulrike

2013-10-01

309

A geometric analysis of mastectomy incisions: Optimizing intraoperative breast volume  

PubMed Central

INTRODUCTION: The advent of acellular dermis-based tissue expander breast reconstruction has placed an increased emphasis on optimizing intraoperative volume. Because skin preservation is a critical determinant of intraoperative volume expansion, a mathematical model was developed to capture the influence of incision dimension on subsequent tissue expander volumes. METHODS: A mathematical equation was developed to calculate breast volume via integration of a geometrically modelled breast cross-section. The equation calculates volume changes associated with excised skin during the mastectomy incision by reducing the arc length of the cross-section. The degree of volume loss is subsequently calculated based on excision dimensions ranging from 35 mm to 60 mm. RESULTS: A quadratic relationship between breast volume and the vertical dimension of the mastectomy incision exists, such that incrementally larger incisions lead to a disproportionally greater amount of volume loss. The vertical dimension of the mastectomy incision – more so than the horizontal dimension – is of critical importance to maintain breast volume. Moreover, the predicted volume loss is more profound in smaller breasts and primarily occurs in areas that affect breast projection on ptosis. CONCLUSIONS: The present study is the first to model the relationship between the vertical dimensions of the mastectomy incision and subsequent volume loss. These geometric principles will aid in optimizing intra-operative volume expansion during expander-based breast reconstruction.

Chopp, David; Rawlani, Vinay; Ellis, Marco; Johnson, Sarah A; Buck, Donald W; Khan, Seema; Bethke, Kevin; Hansen, Nora; Kim, John YS

2011-01-01

310

Qualitative analysis of segmentation methods in detection of Atherosclerosis in Diabetic Patients  

Microsoft Academic Search

Today there is an increase in interest for setting up medical system that can screen a large number of people for life threatening diseases, such as Cardio Vascular Diseases (CVD) in Diabetic Patients. In this paper three different methods of segmentation are discussed. K-means and Fuzzy C-means (FCM) are two methods that use distance metric for segmentation. K-means is implemented

Fahimuddin. Shaik; B. A. Rahim; M. N. G. Prasad; A. SomaSekhar; J. Rao; R. Ravindraiah

2010-01-01

311

SPATIO-TEMPORAL SEGMENTATION OF VIDEO BY HIERARCHICAL MEAN SHIFT ANALYSIS  

Microsoft Academic Search

We describe a simple new technique for spatio-temporal segmenta- tion of video sequences. Each pixel of a 3D space-time video stack is mapped to a 7D feature point whose coordinates include three color components, two motion angle components and two motion position components. The clustering of these feature points pro- vides color segmentation and motion segmentation, as well as a

Daniel DeMenthon

2002-01-01

312

CT-scan images preprocessing and segmentation to improve bioprosthesis leaflets morphological analysis.  

PubMed

The visualization of bioprosthesis leaflet morphology might help to better understand the underlying mechanism of dysfunction in degenerated aortic bioprosthesis. Because today such visualization of bioprosthesis leaflet morphology is intricate to impossible with other imaging techniques, we hypothesized that the processing of multi-detector CT images would allow better visualization of the prosthetic valve leaflets after biological aortic valve replacement. The purpose of our study was to prospectively evaluate patients with a degenerated aortic bioprosthesis, waiting for reoperation, by using 64-slice CT to evaluate prosthetic leaflets morphology. A semi-automatic segmentation of pre-operative tomodensitometric images was conducted, using 2 different implementations of the region growing algorithm. Here we report all segmentation steps (selection of the region of interest, filtering, segmentation). Studied degenerated aortic bioprostheses were represented by two Carpentier-Edwards Supra Annular Valve (porcine leaflets), one Edwards Perimount (pericardial leaflets) and one Medtronic Mosaic (porcine leaflets). Both segmentation methods (Isotropic Region Growing and Stick Region Growing) allowed a semi-automatic segmentation with 3D reconstruction of all bioprosthetic components (stent, leaflets, degeneration/calcifications). Explanted bioprosthesis CT images were also processed and used as reference. Segmentation results were compared by means of quantitative criteria. Semi-automatic segmentation using region growing algorithm seems to provide an interesting approach for the morphological characterization of degenerated aortic bioprostheses. We believe that in the next future CT scan images segmentation may play an important role to better understand the mechanism of dysfunction in failing aortic bioprostheses. Moreover, bioprostheses 3D reconstructions could be integrated into preoperative planning tools to optimize valve-in-valve procedure. PMID:23618610

Ruggieri, V G; Haigron, P; Wang, Q; Esneault, S; Madeleine, R; Heautot, J F; Leguerrier, A; Verhoye, J-Ph

2013-04-22

313

Automatic Story Segmentation of Closed-Caption Text for Semantic Content Analysis of Broadcasted Sports Video  

Microsoft Academic Search

Sports videos can be characterized as a sequence of recurrent semantic story units. Storing sports videos in this story-unit-based form will lead to develop an intelligent content-based retrieval, browsing, and summarization system. The storage requires segmentation of videos and semantic understanding of each segment. Since transcribed broadcasted video speech, the closed-caption text, can be the useful information source for semantic

Naoko Nitta

2002-01-01

314

Explaining Variation in Farm and Farm Business Performance in Respect to Farmer Segmentation Analysis  

Microsoft Academic Search

Results from a pilot application of Defra’s segmentation model applied to the Farm Business Survey for England are presented. Interviews with 750 FBS co-operators during 2010, using a discursive approach, classified co-operators into one of five segmentation groups: Custodians (14.0%); Lifestyle Choice (7.2%); Pragmatists (53.3%); Modern Family Business (21.1%); Challenged Enterprises (4.4%). On average, Modern Family Businesses operated the largest

Paul Wilson; Nicholas Harper; Richard Darling

2011-01-01

315

An Approach to a Comprehensive Test Framework for Analysis and Evaluation of Text Line Segmentation Algorithms  

PubMed Central

The paper introduces a testing framework for the evaluation and validation of text line segmentation algorithms. Text line segmentation represents the key action for correct optical character recognition. Many of the tests for the evaluation of text line segmentation algorithms deal with text databases as reference templates. Because of the mismatch, the reliable testing framework is required. Hence, a new approach to a comprehensive experimental framework for the evaluation of text line segmentation algorithms is proposed. It consists of synthetic multi-like text samples and real handwritten text as well. Although the tests are mutually independent, the results are cross-linked. The proposed method can be used for different types of scripts and languages. Furthermore, two different procedures for the evaluation of algorithm efficiency based on the obtained error type classification are proposed. The first is based on the segmentation line error description, while the second one incorporates well-known signal detection theory. Each of them has different capabilities and convenience, but they can be used as supplements to make the evaluation process efficient. Overall the proposed procedure based on the segmentation line error description has some advantages, characterized by five measures that describe measurement procedures.

Brodic, Darko; Milivojevic, Dragan R.; Milivojevic, Zoran N.

2011-01-01

316

Cell segmentation by multi-resolution analysis and maximum likelihood estimation (MAMLE)  

PubMed Central

Background Cell imaging is becoming an indispensable tool for cell and molecular biology research. However, most processes studied are stochastic in nature, and require the observation of many cells and events. Ideally, extraction of information from these images ought to rely on automatic methods. Here, we propose a novel segmentation method, MAMLE, for detecting cells within dense clusters. Methods MAMLE executes cell segmentation in two stages. The first relies on state of the art filtering technique, edge detection in multi-resolution with morphological operator and threshold decomposition for adaptive thresholding. From this result, a correction procedure is applied that exploits maximum likelihood estimate as an objective function. Also, it acquires morphological features from the initial segmentation for constructing the likelihood parameter, after which the final segmentation is obtained. Conclusions We performed an empirical evaluation that includes sample images from different imaging modalities and diverse cell types. The new method attained very high (above 90%) cell segmentation accuracy in all cases. Finally, its accuracy was compared to several existing methods, and in all tests, MAMLE outperformed them in segmentation accuracy.

2013-01-01

317

Preliminary Development - Head-Neck Simulator. Volume 1: Analysis Volunteer Tests.  

National Technical Information Service (NTIS)

The report documents the initial work of an ongoing research program of which the objective is to develop a head-neck simulator with omni-directional biofidelity. The report is composed of two volumes: Volume I, Analysis Volunteer Tests and Volume II: Mat...

J. S. H. M. Wismans

1986-01-01

318

Latent Factor Analysis to Discover Pathway-Associated Putative Segmental Aneuploidies in Human Cancers  

PubMed Central

Tumor microenvironmental stresses, such as hypoxia and lactic acidosis, play important roles in tumor progression. Although gene signatures reflecting the influence of these stresses are powerful approaches to link expression with phenotypes, they do not fully reflect the complexity of human cancers. Here, we describe the use of latent factor models to further dissect the stress gene signatures in a breast cancer expression dataset. The genes in these latent factors are coordinately expressed in tumors and depict distinct, interacting components of the biological processes. The genes in several latent factors are highly enriched in chromosomal locations. When these factors are analyzed in independent datasets with gene expression and array CGH data, the expression values of these factors are highly correlated with copy number alterations (CNAs) of the corresponding BAC clones in both the cell lines and tumors. Therefore, variation in the expression of these pathway-associated factors is at least partially caused by variation in gene dosage and CNAs among breast cancers. We have also found the expression of two latent factors without any chromosomal enrichment is highly associated with 12q CNA, likely an instance of “trans”-variations in which CNA leads to the variations in gene expression outside of the CNA region. In addition, we have found that factor 26 (1q CNA) is negatively correlated with HIF-1? protein and hypoxia pathways in breast tumors and cell lines. This agrees with, and for the first time links, known good prognosis associated with both a low hypoxia signature and the presence of CNA in this region. Taken together, these results suggest the possibility that tumor segmental aneuploidy makes significant contributions to variation in the lactic acidosis/hypoxia gene signatures in human cancers and demonstrate that latent factor analysis is a powerful means to uncover such a linkage.

Lucas, Joseph E.; Kung, Hsiu-Ni; Chi, Jen-Tsan A.

2010-01-01

319

Global Warming’s Six Americas: An Audience Segmentation Analysis (Invited)  

NASA Astrophysics Data System (ADS)

One of the first rules of effective communication is to “know thy audience.” People have different psychological, cultural and political reasons for acting - or not acting - to reduce greenhouse gas emissions, and climate change educators can increase their impact by taking these differences into account. In this presentation we will describe six unique audience segments within the American public that each responds to the issue in its own distinct way, and we will discuss methods of engaging each. The six audiences were identified using a nationally representative survey of American adults conducted in the fall of 2008 (N=2,164). In two waves of online data collection, the public’s climate change beliefs, attitudes, risk perceptions, values, policy preferences, conservation, and energy-efficiency behaviors were assessed. The data were subjected to latent class analysis, yielding six groups distinguishable on all the above dimensions. The Alarmed (18%) are fully convinced of the reality and seriousness of climate change and are already taking individual, consumer, and political action to address it. The Concerned (33%) - the largest of the Six Americas - are also convinced that global warming is happening and a serious problem, but have not yet engaged with the issue personally. Three other Americas - the Cautious (19%), the Disengaged (12%) and the Doubtful (11%) - represent different stages of understanding and acceptance of the problem, and none are actively involved. The final America - the Dismissive (7%) - are very sure it is not happening and are actively involved as opponents of a national effort to reduce greenhouse gas emissions. Mitigating climate change will require a diversity of messages, messengers and methods that take into account these differences within the American public. The findings from this research can serve as guideposts for educators on the optimal choices for reaching and influencing target groups with varied informational needs, values and beliefs.

Roser-Renouf, C.; Maibach, E.; Leiserowitz, A.

2009-12-01

320

Wireless capsule endoscopy video segmentation using an unsupervised learning approach based on probabilistic latent semantic analysis with scale invariant features.  

PubMed

Since wireless capsule endoscopy (WCE) is a novel technology for recording the videos of the digestive tract of a patient, the problem of segmenting the WCE video of the digestive tract into subvideos corresponding to the entrance, stomach, small intestine, and large intestine regions is not well addressed in the literature. A selected few papers addressing this problem follow supervised leaning approaches that presume availability of a large database of correctly labeled training samples. Considering the difficulties in procuring sizable WCE training data sets needed for achieving high classification accuracy, we introduce in this paper an unsupervised learning approach that employs Scale Invariant Feature Transform (SIFT) for extraction of local image features and the probabilistic latent semantic analysis (pLSA) model used in the linguistic content analysis for data clustering. Results of experimentation indicate that this method compares well in classification accuracy with the state-of-the-art supervised classification approaches to WCE video segmentation. PMID:22010158

Shen, Yao; Guturu, Parthasarathy Partha; Buckles, Bill P

2011-10-17

321

Airway segmentation and analysis for the study of mouse models of lung disease using micro-CT  

NASA Astrophysics Data System (ADS)

Animal models of lung disease are gaining importance in understanding the underlying mechanisms of diseases such as emphysema and lung cancer. Micro-CT allows in vivo imaging of these models, thus permitting the study of the progression of the disease or the effect of therapeutic drugs in longitudinal studies. Automated analysis of micro-CT images can be helpful to understand the physiology of diseased lungs, especially when combined with measurements of respiratory system input impedance. In this work, we present a fast and robust murine airway segmentation and reconstruction algorithm. The algorithm is based on a propagating fast marching wavefront that, as it grows, divides the tree into segments. We devised a number of specific rules to guarantee that the front propagates only inside the airways and to avoid leaking into the parenchyma. The algorithm was tested on normal mice, a mouse model of chronic inflammation and a mouse model of emphysema. A comparison with manual segmentations of two independent observers shows that the specificity and sensitivity values of our method are comparable to the inter-observer variability, and radius measurements of the mainstem bronchi reveal significant differences between healthy and diseased mice. Combining measurements of the automatically segmented airways with the parameters of the constant phase model provides extra information on how disease affects lung function.

Artaechevarria, X.; Pérez-Martín, D.; Ceresa, M.; de Biurrun, G.; Blanco, D.; Montuenga, L. M.; van Ginneken, B.; Ortiz-de-Solorzano, C.; Muñoz-Barrutia, A.

2009-11-01

322

Airway segmentation and analysis for the study of mouse models of lung disease using micro-CT.  

PubMed

Animal models of lung disease are gaining importance in understanding the underlying mechanisms of diseases such as emphysema and lung cancer. Micro-CT allows in vivo imaging of these models, thus permitting the study of the progression of the disease or the effect of therapeutic drugs in longitudinal studies. Automated analysis of micro-CT images can be helpful to understand the physiology of diseased lungs, especially when combined with measurements of respiratory system input impedance. In this work, we present a fast and robust murine airway segmentation and reconstruction algorithm. The algorithm is based on a propagating fast marching wavefront that, as it grows, divides the tree into segments. We devised a number of specific rules to guarantee that the front propagates only inside the airways and to avoid leaking into the parenchyma. The algorithm was tested on normal mice, a mouse model of chronic inflammation and a mouse model of emphysema. A comparison with manual segmentations of two independent observers shows that the specificity and sensitivity values of our method are comparable to the inter-observer variability, and radius measurements of the mainstem bronchi reveal significant differences between healthy and diseased mice. Combining measurements of the automatically segmented airways with the parameters of the constant phase model provides extra information on how disease affects lung function. PMID:19887716

Artaechevarria, X; Pérez-Martín, D; Ceresa, M; de Biurrun, G; Blanco, D; Montuenga, L M; van Ginneken, B; Ortiz-de-Solorzano, C; Muñoz-Barrutia, A

2009-11-04

323

Stress and strain analysis of contractions during ramp distension in partially obstructed guinea pig jejunal segments  

PubMed Central

Previous studies have demonstrated morphological and biomechanical remodeling in the intestine proximal to an obstruction. The present study aimed to obtain stress and strain thresholds to initiate contraction and the maximal contraction stress and strain in partially obstructed guinea pig jejunal segments. Partial obstruction and sham operations were surgically created in mid-jejunum of male guinea pigs. The animals survived 2, 4, 7, and 14 days, respectively. Animals not being operated on served as normal controls. The segments were used for no-load state, zero-stress state and distension analyses. The segment was inflated to 10 cmH2O pressure in an organ bath containing 37°C Krebs solution and the outer diameter change was monitored. The stress and strain at the contraction threshold and at maximum contraction were computed from the diameter, pressure and the zero-stress state data. Young’s modulus was determined at the contraction threshold. The muscle layer thickness in obstructed intestinal segments increased up to 300%. Compared with sham-obstructed and normal groups, the contraction stress threshold, the maximum contraction stress and the Young’s modulus at the contraction threshold increased whereas the strain threshold and maximum contraction strain decreased after 7 days obstruction (P<0.05 and 0.01). In conclusion, in the partially obstructed intestinal segments, a larger distension force was needed to evoke contraction likely due to tissue remodeling. Higher contraction stresses were produced and the contraction deformation (strain) became smaller.

Zhao, Jingbo; Liao, Donghua; Yang, Jian; Gregersen, Hans

2011-01-01

324

Tumor burden analysis on computed tomography by automated liver and tumor segmentation.  

PubMed

The paper presents the automated computation of hepatic tumor burden from abdominal computed tomography (CT) images of diseased populations with images with inconsistent enhancement. The automated segmentation of livers is addressed first. A novel 3-D affine invariant shape parameterization is employed to compare local shape across organs. By generating a regular sampling of the organ's surface, this parameterization can be effectively used to compare features of a set of closed 3-D surfaces point-to-point, while avoiding common problems with the parameterization of concave surfaces. From an initial segmentation of the livers, the areas of atypical local shape are determined using training sets. A geodesic active contour corrects locally the segmentations of the livers in abnormal images. Graph cuts segment the hepatic tumors using shape and enhancement constraints. Liver segmentation errors are reduced significantly and all tumors are detected. Finally, support vector machines and feature selection are employed to reduce the number of false tumor detections. The tumor detection true position fraction of 100% is achieved at 2.3 false positives/case and the tumor burden is estimated with 0.9% error. Results from the test data demonstrate the method's robustness to analyze livers from difficult clinical cases to allow the temporal monitoring of patients with hepatic cancer. PMID:22893379

Linguraru, Marius George; Richbourg, William J; Liu, Jianfei; Watt, Jeremy M; Pamulapati, Vivek; Wang, Shijun; Summers, Ronald M

2012-08-07

325

Consumer Reactions to Four Prototype Patient Package Inserts for Erythromycin: A Focus Group Analysis. Volume I: Summary Analysis. Volume II: Edited Transcriptions.  

National Technical Information Service (NTIS)

Report covers focus group discussions conducted by the Uniworld Group for FDA regarding four versions of erythromycin PPIs. Volume I contains a content analysis of the four different PPI versions and major observations made by the focus group participants...

L. A. Morris S. Morris D. Thilman J. Guerin

1979-01-01

326

Style, content and format guide for writing safety analysis documents. Volume 1, Safety analysis reports for DOE nuclear facilities  

SciTech Connect

The purpose of Volume 1 of this 4-volume style guide is to furnish guidelines on writing and publishing Safety Analysis Reports (SARs) for DOE nuclear facilities at Sandia National Laboratories. The scope of Volume 1 encompasses not only the general guidelines for writing and publishing, but also the prescribed topics/appendices contents along with examples from typical SARs for DOE nuclear facilities.

Not Available

1994-06-01

327

Nuclear Volumes: An Analysis During a Cell Cycle  

Microsoft Academic Search

Cells in root meristems of Vicia faba are heterogeneous for cell cycle duration, nuclear volume and cell shape. The present study was made: (1) to determine volumes of meristem cell nuclei, (2) to analyze changes in nuclear volumes during a cell cycle in a marked population of tetraploid cells in the meristems of long lateral roots.\\u000aThe results show that

Jaya Bansal

1975-01-01

328

Segmentation and analysis of breast cancer pathological images by an adaptive-sized hybrid neural network  

NASA Astrophysics Data System (ADS)

The number of nuclei on a pathology image assists pathologists in consistent diagnosis of breast cancer. Currently, most pathologists make a diagnosis based on a rough estimation of the number of nuclei on pathology images. Because of the rough estimation, the diagnosis is not objective. To assist pathologists to make a consistent, objective and fast diagnosis, it is necessary to develop a computer system to automatically recognize and count several kinds of nuclei. We have developed an algorithm for the automatic segmentation and counting of nuclei in breast cancer pathology images. In the development of the algorithm, we proposed two novel methods: an adaptive-sized hybrid neural network for the automatic segmentation of nuclei, insulin-like growth factor-II messenger RNAs and other structures, and the combined use of both the focused gradient filter and the watersheds algorithm for segmentation of overlapped nuclei.

Hasegawa, Akira; Cullen, Kevin J.; Mun, Seong K.

1996-04-01

329

Validity of segmental multiple-frequency bioelectrical impedance analysis to estimate body composition of adults across a range of body mass indexes  

Microsoft Academic Search

ObjectiveWe compared body composition estimates using an eight-electrode, segmental, multiple-frequency bioelectrical impedance analysis (segmental MF-BIA) and dual x-ray absorptiometry (DXA) in a group of healthy adults with a range of body mass indexes (BMIs).

Kimberly J. Shafer; William A. Siders; LuAnn K. Johnson; Henry C. Lukaski

2009-01-01

330

Segmental wall-motion analysis in the right anterior oblique projection: comparison of exercise equilibrium radionuclide ventriculography and exercise contrast ventriculography  

Microsoft Academic Search

Thirty-nine patients with known or suspected coronary artery disease were studied at rest and during supine bicycle exercise with radionuclide and contrast left ventriculography. Analysis of regional wall motion was made by visual evaluation of the five standard 30° right anterior oblique (RAO) wall segments in the contrast images and the corresponding 10° RAO radionuclide segments. The radionuclide studies were

T. J. Brady; J. H. Thrall; J. W. Jr. Keyes; J. F. Brymer; J. A. Walton; B. Pitt

1980-01-01

331

Heart Rate Variability Analysis of Ischemic and Heart Rate Related ST-segment Deviation Episodes Based on Time-frequency Method  

Microsoft Academic Search

ST-segment deviation is the routine method for the diagnosis of coronary heart diseases. However, other phenomena, such as heart rate changes and a posture change can cause similar manifestations in the ST segment, lowing the sensitivity and specificity of the detection. In this study, a different method, based on time-frequency analysis of heart rate variability, was proposed to evaluate the

Wang Xing; Xu Liang; Sun Zhongwei; Yang Zibin; Peng Yi

2007-01-01

332

A fully-automatic caudate nucleus segmentation of brain MRI: Application in volumetric analysis of pediatric attention-deficit/hyperactivity disorder  

PubMed Central

Background Accurate automatic segmentation of the caudate nucleus in magnetic resonance images (MRI) of the brain is of great interest in the analysis of developmental disorders. Segmentation methods based on a single atlas or on multiple atlases have been shown to suitably localize caudate structure. However, the atlas prior information may not represent the structure of interest correctly. It may therefore be useful to introduce a more flexible technique for accurate segmentations. Method We present Cau-dateCut: a new fully-automatic method of segmenting the caudate nucleus in MRI. CaudateCut combines an atlas-based segmentation strategy with the Graph Cut energy-minimization framework. We adapt the Graph Cut model to make it suitable for segmenting small, low-contrast structures, such as the caudate nucleus, by defining new energy function data and boundary potentials. In particular, we exploit information concerning the intensity and geometry, and we add supervised energies based on contextual brain structures. Furthermore, we reinforce boundary detection using a new multi-scale edgeness measure. Results We apply the novel CaudateCut method to the segmentation of the caudate nucleus to a new set of 39 pediatric attention-deficit/hyperactivity disorder (ADHD) patients and 40 control children, as well as to a public database of 18 subjects. We evaluate the quality of the segmentation using several volumetric and voxel by voxel measures. Our results show improved performance in terms of segmentation compared to state-of-the-art approaches, obtaining a mean overlap of 80.75%. Moreover, we present a quantitative volumetric analysis of caudate abnormalities in pediatric ADHD, the results of which show strong correlation with expert manual analysis. Conclusion CaudateCut generates segmentation results that are comparable to gold-standard segmentations and which are reliable in the analysis of differentiating neuroanatomical abnormalities between healthy controls and pediatric ADHD.

2011-01-01

333

Yucca Mountain transportation routes: Preliminary characterization and risk analysis; Volume 2, Figures [and] Volume 3, Technical Appendices  

SciTech Connect

This report presents appendices related to the preliminary assessment and risk analysis for high-level radioactive waste transportation routes to the proposed Yucca Mountain Project repository. Information includes data on population density, traffic volume, ecologically sensitive areas, and accident history.

Souleyrette, R.R. II; Sathisan, S.K.; di Bartolo, R. [Nevada Univ., Las Vegas, NV (United States). Transportation Research Center] [Nevada Univ., Las Vegas, NV (United States). Transportation Research Center

1991-05-31

334

Exposure of intestinal segments to hemiacidrin: analysis of metabolic and histological effects using a rat model.  

PubMed

Using a previously reported rat model, we examined the effects of intestinal perfusion with hemiacidrin on calcium and magnesium homeostasis, and inspected the intestinal segments for histological alterations following exposure to the solution. Intestinal irrigation with hemiacidrin resulted in a significant increase in serum magnesium. Urinary excretion rates of calcium increased 8-fold and magnesium excretion rates increased 5-fold over control values. Hemiacidrin appeared to have detrimental effects on the integrity of the intestinal mucosa, and irrigation should be done with caution in patients whose urinary tract has been reconstructed with intestinal segments. PMID:8022005

Brandell, R A; Hall, M C; Koch, M O; Braren, H V

1994-08-01

335

Probabilistic Analysis of Activation Volumes Generated During Deep Brain Stimulation  

PubMed Central

Deep brain stimulation (DBS) is an established therapy for the treatment of Parkinson’s disease (PD) and shows great promise for the treatment of several other disorders. However, while the clinical analysis of DBS has received great attention, a relative paucity of quantitative techniques exists to define the optimal surgical target and most effective stimulation protocol for a given disorder. In this study we describe a methodology that represents an evolutionary addition to the concept of a probabilistic brain atlas, which we call a probabilistic stimulation atlas (PSA). We outline steps to combine quantitative clinical outcome measures with advanced computational models of DBS to identify regions where stimulation-induced activation could provide the best therapeutic improvement on a per-symptom basis. While this methodology is relevant to any form of DBS, we present example results from subthalamic nucleus (STN) DBS for PD. We constructed patient-specific computer models of the volume of tissue activated (VTA) for 163 different stimulation parameter settings which were tested in six patients. We then assigned clinical outcome scores to each VTA and compiled all of the VTAs into a PSA to identify stimulation-induced activation targets that maximized therapeutic response with minimal side effects. The results suggest that selection of both electrode placement and clinical stimulation parameter settings could be tailored to the patient’s primary symptoms using patient-specific models and PSAs.

Butson, Christopher R.; Cooper, Scott E.; Henderson, Jaimie M.; Wolgamuth, Barbara; McIntyre, Cameron C.

2010-01-01

336

Influence of Pressure on Chain and Segmental Dynamics in Polyisoprene  

SciTech Connect

We present detailed studies of variation in segmental and chain dynamics of polyisoprene under pressure. Samples with two molecular weights (MW), 2.4 and 25 kg/mol (below and above entanglement), were investigated. Dielectric spectroscopy measurements at isobaric and isothermal conditions exhibit clear differences in temperature and pressure dependencies of chain and segmental relaxation times. Moreover, application of pressure increases time separation between the segmental and normal (chain) modes at the isochronic conditions. This increase can be explained by an effective increase in number of Rouse segments under compression at the same segmental relaxation time. Our analysis also reveals that the thermodynamic scaling of the relaxation times (log vs TV , V is volume) does not work well simultaneously for both processes.

Pawlus, Sebastian [University of Silesia, Uniwersytecka, Katowice, Poland; Sokolov, Alexei P [ORNL; Paluch, Marian [University of Silesia, Uniwersytecka, Katowice, Poland; Mierzwa, Michal [University of Silesia, Uniwersytecka, Katowice, Poland

2010-01-01

337

Estimation of the Click Volume by Large Scale Regression Analysis  

Microsoft Academic Search

How could one estimate the total number of clicks a new ad- vertisement could potentially receive in the current market? This ques- tion, called the click volume estimation problem is investigated in this paper. This constitutes a new research direction for advertising engines. We propose a model of computing an estimation of the click volume. A key component of our

Yury Lifshits; Dirk Nowotka

2007-01-01

338

Analysis of Major Item Redistribution/Substitution Policies. Volume II.  

National Technical Information Service (NTIS)

This is a second volume of a two-part report. The listings of substitute items shown in this volume are arranged by authorized Line Item Number (LIN) in ascending order. Appendix A segregates the total substitutes by manager code and contains 12 sections....

U. R. Poskus

1980-01-01

339

A Genetic Analysis of Brain Volumes and IQ in Children  

ERIC Educational Resources Information Center

|In a population-based sample of 112 nine-year old twin pairs, we investigated the association among total brain volume, gray matter and white matter volume, intelligence as assessed by the Raven IQ test, verbal comprehension, perceptual organization and perceptual speed as assessed by the Wechsler Intelligence Scale for Children-III. Phenotypic…

van Leeuwen, Marieke; Peper, Jiska S.; van den Berg, Stephanie M.; Brouwer, Rachel M.; Hulshoff Pol, Hilleke E.; Kahn, Rene S.; Boomsma, Dorret I.

2009-01-01

340

AID Integrated Low Cost Health Projects. Volume II: Analysis.  

National Technical Information Service (NTIS)

This report, the second of two volumes, analyzes the nutrition interventions in 39 A.I.D. primary health care projects in Africa, Asia, Latin America, and the Near East. The first volume provided a general review of the individual projects. Introductory s...

N. Baumslag C. Roesel E. Sabin

1978-01-01

341

Hospital benefit segmentation.  

PubMed

Market segmentation is an important topic to both health care practitioners and researchers. The authors explore the relative importance that health care consumers attach to various benefits available in a major metropolitan area hospital. The purposes of the study are to test, and provide data to illustrate, the efficacy of one approach to hospital benefit segmentation analysis. PMID:10280370

Finn, D W; Lamb, C W

1986-12-01

342

The segmented chirp Z-transform and its application in spectrum analysis  

Microsoft Academic Search

The chirp Z-transform (CZT) algorithm is known to be more flexible than the fast Fourier transform in calculating the frequency spectrum. However, its mathematical implementation is complex, and additional memory space is required. A modified CZT algorithm called the segmented chirp Z transform (SCZT) is introduced. SCZT has the ability to handle a very large amount of input data with

T. T. Wang

1990-01-01

343

Marginal and segmental mandibulectomy in patients with oral cancer: a statistical analysis of 106 cases  

Microsoft Academic Search

Purpose: The treatment of oral squamous cell carcinoma may require mandibular resection to secure adequate margin. This bone resection often is segmental or marginal mandibulectomy. The purpose of this work was to evaluate the local control and survival after surgical treatment of oral cancer, according to these 2 different mandibular resection procedures.Patients and methods: We conducted a retrospective study of

Mario Fernando Muñoz Guerra; Luis Naval G??as; Francisco Rodr??guez Campo; Jesús Sastre Pérez

2003-01-01

344

Segmental and Positional Effects on Children's Coda Production: Comparing Evidence from Perceptual Judgments and Acoustic Analysis  

ERIC Educational Resources Information Center

|Children's early productions are highly variable. Findings from children's early productions of grammatical morphemes indicate that some of the variability is systematically related to segmental and phonological factors. Here, we extend these findings by assessing 2-year-olds' production of non-morphemic codas using both listener decisions and…

Theodore, Rachel M.; Demuth, Katherine; Shattuck-Hufnagel, Stephanie

2012-01-01

345

An on-line system for the quantitative analysis of coronary arterial segments  

Microsoft Academic Search

The online quantification of coronary arteries is important for the objective and accurate assessment of the effects of coronary intervention procedures. The basic principles of a quantitative coronary arteriography (QCA) software package, to be implemented on the Philips DCI system, is described. First, a centerline of the selected arterial segment is defined. After the beginning and endpoints are manually defined,

C. D. von Land; G. Loois; J. J. Gerbrands; J. H. C. Reiber

1989-01-01

346

Performance Analysis of CATR Reflector with Super Hybrid Modulated Segmented Exponential Serrated Edges  

Microsoft Academic Search

This paper presented a theoretical and numerical investigation of the Compact Antenna Test Range (CATR) equipped with Super Hybrid Modulated Segmented Exponential Serrations (SHMSES). The investigation was based on diffraction theory and, more specifically, the Fresnel diffraction formulation. The CATR provides uniform illumination within the Fresnel region to test antenna. Application of serrated edges has been shown to be a

T. Venkata Rama Krishna; P. Siddaiah; B. Prabhakara Rao

2007-01-01

347

A Marked Point Process of Rectangles and Segments for Automatic Analysis of Digital Elevation Models  

Microsoft Academic Search

This work presents a framework for automatic feature extraction from images using stochastic geometry. Features in images are modeled as realizations of a spatial point process of geometrical shapes. This framework allows the incorporation of a priori knowledge on the spatial repartition of features. More specifically, we present a model based on the superposition of a process of segments and

Mathias Ortner; Xavier Descombes; Josiane Zerubia

2008-01-01

348

Infants' Early Ability to Segment the Conversational Speech Signal Predicts Later Language Development: A Retrospective Analysis  

Microsoft Academic Search

Two studies examined relationships between infants' early speech processing performance and later language and cognitive outcomes. Study 1 found that performance on speech segmentation tasks before 12 months of age related to expressive vocabulary at 24 months. However, performance on other tasks was not related to 2-year vocabulary. Study 2 assessed linguistic and cognitive skills at 4–6 years of age

Rochelle Newman; Nan Bernstein Ratner; Ann Marie Jusczyk; Peter W. Jusczyk; Kathy Ayala Dow

2006-01-01

349

Segmentation based on customer profitability — retrospective analysis of retail bank customer bases  

Microsoft Academic Search

Segmentation continues to be an important marketing concept also in a relationship marketing context. Relationship marketing is, however, more interested in enhancing the existing customer relationships and this generates a need for a better understanding of the existing customer base. The paper argues that “retrospective” or historical analyses, that facilitate the calculation of customer relationship profitability, form an excellent starting

Kaj Storbacka

1997-01-01

350

Infants' Early Ability to Segment the Conversational Speech Signal Predicts Later Language Development: A Retrospective Analysis  

ERIC Educational Resources Information Center

|Two studies examined relationships between infants' early speech processing performance and later language and cognitive outcomes. Study 1 found that performance on speech segmentation tasks before 12 months of age related to expressive vocabulary at 24 months. However, performance on other tasks was not related to 2-year vocabulary. Study 2…

Newman, Rochelle; Ratner, Nan Bernstein; Jusczyk, Ann Marie; Jusczyk, Peter W.; Dow, Kathy Ayala

2006-01-01

351

DRM workflow analysis for over-the-top HTTP segmented delivery  

Microsoft Academic Search

Monetization of premium video content requires two key components: quality and security. In the mobile space, quality issues have been largely address in recent years through faster CPUs and segment-based HTTP adaptive bitrate delivery (e.g., Apple R ! HTTP Live Streaming, Adobe R ! HTTP

Kevin J. Ma; Raj Nair; Radim Bartos

2011-01-01

352

Mathematical analysis of blood flow through an arterial segment with time?dependent stenosis  

Microsoft Academic Search

A mathematical model is developed here with an aim to study the pulsatile flow of blood through an arterial segment having a time?dependent stenosis. Blood is considered to consist of a core layer where erythrocytes are concentrated and a peripheral plasma layer that is free from erythrocytes. The plasma layer is taken to behave as a Newtonian fluid, while the

J. C. Misra; S. D. Adhikary; G. C. Shit

2008-01-01

353

A novel color image segmentation method and its application to white blood cell image analysis  

Microsoft Academic Search

According to the fact that the H component in HSI color space contains most of the white blood cell information, and the S component contains the structure information of the white blood cell nucleus, we develop an iterative Otsu's approach based on circular histogram for the leukocyte segmentation by taking full advantage of this knowledge. Experimental results show that this

Jianhua WU; Pingping ZENG; Yuan ZHOU; Christian OLIVIER

2006-01-01

354

Phylogenetic analysis of the S segment from Juquitiba hantavirus: identification of two distinct lineages in Oligoryzomys nigripes.  

PubMed

The purpose of this study was to investigate the phylogenetic relationship of the Juquitiba virus (JUQV) carried by Oligoryzomys nigripes in endemic and non-endemic areas of Brazil. Wild rodents infected with the Juquitiba virus (JUQV) were sampled from a non-Hantavirus Cardiopulmonary Syndrome endemic area in Brazil. Three strains from O. nigripes were identified by the sequencing of the complete S segment and compared to previous studies of JUQV available in GenBank. The phylogenetic analysis of the complete S segment revealed two distinct clades; the first clade was composed of the JUQV from two non-endemic areas in Brazil and the second clade contained JUQV strains from Argentina, Paraguay and other Brazilian endemic areas. PMID:23751399

Guterres, Alexandro; de Oliveira, Renata Carvalho; Fernandes, Jorlan; D'Andrea, Paulo Sérgio; Bonvicino, Cibele R; Bragagnolo, Camila; Guimarães, Gustavo Ducoff; Almada, Gilton Luiz; Machado, Rosangela Rosa; Lavocat, Marília; Elkhoury, Mauro da Rosa; Schrago, Carlos Guerra; de Lemos, Elba Regina Sampaio

2013-06-07

355

National Aviation Fuel Scenario Analysis Program (NAFSAP). Volume I. Model Description. Volume II. User Manual.  

National Technical Information Service (NTIS)

This report forecasts air carrier jet fuel usage by body type for three user defined markets. The model contains options which allow the user to easily change the composition of the future fleet so that fuel usage scenarios can be 'run'. Both Volumes I an...

S. G. Vahovich

1980-01-01

356

High-Volume Data Analysis Suite (HVDAS) Manual November-17-2003.  

National Technical Information Service (NTIS)

This manual describes the design, implementation and use of the High- Volume Data Analysis Suite (HVDAS), which is a collection of parallelized statistical analysis software packages for Linux clusters. HVDAS is designed to reduce and perform statistical ...

G. A. Hildstrom

2003-01-01

357

DEVELOPMENT AND APPLICATION OF A WATER SUPPLY COST ANALYSIS SYSTEM. VOLUME II  

EPA Science Inventory

A cost analysis for system water supply utility management has been developed and implemented in Kenton County, Kentucky, Water District No. 1. This volume contains the program documentation for the cost analysis system....

358

Engineering analysis and evaluation of the Centralia mine fire. Volume 2  

SciTech Connect

Provided in volume 2 is an analysis of the mine fire, which defines fire conditions, identifies ventilation patterns, and determines the progression of the fire. Options to control and/or extinguish the fire are examined, based on the analysis.

Not Available

1983-07-01

359

Microstructural analysis of pineal volume using trueFISP imaging  

PubMed Central

AIM: To determine the spectrum of pineal microstructures (solid/cystic parts) in a large clinical population using a high-resolution 3D-T2-weighted sequence. METHODS: A total of 347 patients enrolled for cranial magnetic resonance imaging were randomly included in this study. Written informed consent was obtained from all patients. The exclusion criteria were artifacts or mass lesions prohibiting evaluation of the pineal gland in any of the sequences. True-FISP-3D-imaging (1.5-T, isotropic voxel 0.9 mm) was performed in 347 adults (55.4 ± 18.1 years). Pineal gland volume (PGV), cystic volume, and parenchyma volume (cysts excluded) were measured manually. RESULTS: Overall, 40.3% of pineal glands were cystic. The median PGV was 54.6 mm3 (78.33 ± 89.0 mm3), the median cystic volume was 5.4 mm3 (15.8 ± 37.2 mm3), and the median parenchyma volume was 53.6 mm3 (71.9 ± 66.7 mm3). In cystic glands, the standard deviation of the PGV was substantially higher than in solid glands (98% vs 58% of the mean). PGV declined with age (r = -0.130, P = 0.016). CONCLUSION: The high interindividual volume variation is mainly related to cysts. Pineal parenchyma volume decreased slightly with age, whereas gender-related effects appear to be negligible.

Bumb, Jan M; Brockmann, Marc A; Groden, Christoph; Nolte, Ingo

2013-01-01

360

Kinematic analysis of a multi-segment foot model for research and clinical applications: a repeatability analysis  

Microsoft Academic Search

An unbiased understanding of foot kinematics has been difficult to achieve due to the complexity of foot structure and motion. We have developed a protocol for evaluation of foot kinematics during barefoot walking based on a multi-segment foot model. Stereophotogrammetry was used to measure retroreflective markers on three segments of the foot plus the tibia. Repeatability was evaluated between-trial, between-day

M. C. Carson; M. E. Harrington; N. Thompson; J. J. O’Connor; T. N. Theologis

2001-01-01

361

Liver segmentation in contrast enhanced CT data using graph cuts and interactive 3D segmentation refinement methods  

SciTech Connect

Purpose: Liver segmentation is an important prerequisite for the assessment of liver cancer treatment options like tumor resection, image-guided radiation therapy (IGRT), radiofrequency ablation, etc. The purpose of this work was to evaluate a new approach for liver segmentation. Methods: A graph cuts segmentation method was combined with a three-dimensional virtual reality based segmentation refinement approach. The developed interactive segmentation system allowed the user to manipulate volume chunks and/or surfaces instead of 2D contours in cross-sectional images (i.e, slice-by-slice). The method was evaluated on twenty routinely acquired portal-phase contrast enhanced multislice computed tomography (CT) data sets. An independent reference was generated by utilizing a currently clinically utilized slice-by-slice segmentation method. After 1 h of introduction to the developed segmentation system, three experts were asked to segment all twenty data sets with the proposed method. Results: Compared to the independent standard, the relative volumetric segmentation overlap error averaged over all three experts and all twenty data sets was 3.74%. Liver segmentation required on average 16 min of user interaction per case. The calculated relative volumetric overlap errors were not found to be significantly different [analysis of variance (ANOVA) test, p = 0.82] between experts who utilized the proposed 3D system. In contrast, the time required by each expert for segmentation was found to be significantly different (ANOVA test, p = 0.0009). Major differences between generated segmentations and independent references were observed in areas were vessels enter or leave the liver and no accepted criteria for defining liver boundaries exist. In comparison, slice-by-slice based generation of the independent standard utilizing a live wire tool took 70.1 min on average. A standard 2D segmentation refinement approach applied to all twenty data sets required on average 38.2 min of user interaction and resulted in statistically not significantly different segmentation error indices (ANOVA test, significance level of 0.05). Conclusions: All three experts were able to produce liver segmentations with low error rates. User interaction time savings of up to 71% compared to a 2D refinement approach demonstrate the utility and potential of our approach. The system offers a range of different tools to manipulate segmentation results, and some users might benefit from a longer learning phase to develop efficient segmentation refinement strategies. The presented approach represents a generally applicable segmentation approach that can be applied to many medical image segmentation problems.

Beichel, Reinhard; Bornik, Alexander; Bauer, Christian; Sorantin, Erich [Departments of Electrical and Computer Engineering and Internal Medicine, Iowa Institute for Biomedical Imaging, University of Iowa, Iowa City, Iowa 52242 (United States); Institute for Computer Graphics and Vision, Graz University of Technology, Inffeldgasse 16, A-8010 Graz (Austria); Department of Electrical and Computer Engineering, Iowa Institute for Biomedical Imaging, University of Iowa, Iowa City, Iowa 52242 (United States); Department of Radiology, Medical University Graz, Auenbruggerplatz 34, A-8010 Graz (Austria)

2012-03-15

362

Accident/Incident Data Analysis Database Summaries. Volume 1.  

National Technical Information Service (NTIS)

The two volume report provides a compendium of the existence, availability, limitations, and applicability of aviation accident and incident databases for use in human factors research. An aviation and data processing oriented form was used to survey 41 U...

T. P. Murphy R. J. Levendoski

1989-01-01

363

Requirements Analysis for Milestone Tracking System. Volume 2.  

National Technical Information Service (NTIS)

Volume II of this report concerns the efforts undertaken with respect to a Milestone Tracking System. The purpose of this task was to analyze the feasibility and cost effectiveness of developing milestone tracking system for internal use within DARPA whic...

1983-01-01

364

Insider's Guide to Managing Public Housing. Volume 2: Analysis Guides.  

National Technical Information Service (NTIS)

Volume II of a two - part guide to public housing management uses a self - interview format to analyze current management practices in 10 functional areas: general administration, project management, finance and accounting, maintenance and custodial, purc...

R. Kolodny R. D. Baron R. J. Struyk

1983-01-01

365

Specification of a Human Reliability Data Bank for Conducting HRA (Human Reliability Analysis) Segments of PRAs (Probabilistic Risk Assessments for Nuclear Power Plants.  

National Technical Information Service (NTIS)

This document specifies the personnel, resources, policies, and procedures for implementing and operating a human reliability data bank specifically tailored to support human reliability analysis (HRA) segments of probabilistic risk assessments (PRAs) for...

M. D. Donovan M. K. Comer

1985-01-01

366

Multimodal retinal vessel segmentation from spectral-domain optical coherence tomography and fundus photography.  

PubMed

Segmenting retinal vessels in optic nerve head (ONH) centered spectral-domain optical coherence tomography (SD-OCT) volumes is particularly challenging due to the projected neural canal opening (NCO) and relatively low visibility in the ONH center. Color fundus photographs provide a relatively high vessel contrast in the region inside the NCO, but have not been previously used to aid the SD-OCT vessel segmentation process. Thus, in this paper, we present two approaches for the segmentation of retinal vessels in SD-OCT volumes that each take advantage of complimentary information from fundus photographs. In the first approach (referred to as the registered-fundus vessel segmentation approach), vessels are first segmented on the fundus photograph directly (using a k-NN pixel classifier) and this vessel segmentation result is mapped to the SD-OCT volume through the registration of the fundus photograph to the SD-OCT volume. In the second approach (referred to as the multimodal vessel segmentation approach), after fundus-to-SD-OCT registration, vessels are simultaneously segmented with a k -NN classifier using features from both modalities. Three-dimensional structural information from the intraretinal layers and neural canal opening obtained through graph-theoretic segmentation approaches of the SD-OCT volume are used in combination with Gaussian filter banks and Gabor wavelets to generate the features. The approach is trained on 15 and tested on 19 randomly chosen independent image pairs of SD-OCT volumes and fundus images from 34 subjects with glaucoma. Based on a receiver operating characteristic (ROC) curve analysis, the present registered-fundus and multimodal vessel segmentation approaches [area under the curve (AUC) of 0.85 and 0.89, respectively] both perform significantly better than the two previous OCT-based approaches (AUC of 0.78 and 0.83, p < 0.05). The multimodal approach overall performs significantly better than the other three approaches (p < 0.05). PMID:22759443

Hu, Zhihong; Niemeijer, Meindert; Abràmoff, Michael D; Garvin, Mona K

2012-06-29

367

Intravenous Electron-Beam Computed Tomographic Coronary Angiography for Segmental Analysis of Coronary Artery Stenoses  

Microsoft Academic Search

Objectives. We sought to identify and localize significant coronary stenoses on a segmental basis by electron-beam computed tomography (EBCT) and intravenous administration of a contrast agent.Background. The clinical applicability and limitations of intravenous EBCT coronary angiography have not been defined.Methods. EBCT was performed within 24 h of selective coronary angiography (SCA) in 28 patients (19 men and 9 women, mean

Axel Schmermund; Benno J Rensing; Patrick F Sheedy; Malcolm R Bell; John A Rumberger

1998-01-01

368

Facial Expression During Emotional Monologues in Unilateral Stroke: An Analysis of Monologue Segments  

Microsoft Academic Search

Emotional monologues of brain-damaged subjects were examined to determine whether interhemispheric or intrahemispheric differences exist for facial emotional expression. A special feature was the comparison of expressions produced during the initial, middle, and last segments of the monologues. Videotaped emotional and non-emotional monologues from the New York Emotion Battery (Borod, Welkowitz, & Obler, 1992) of eight right brain-damaged (RBD), eight

Seta Kazandjian; Joan C. Borod; Adam M. Brickman

2007-01-01

369

Tracheoplasty for long segment congenital tracheal stenosis: analysis of 29 patients over two decades  

Microsoft Academic Search

Purpose: The authors determined the long-term outcome of patients who underwent surgical repair of long-segment congenital tracheal stenosis (LCTS) and compared the quality of cartilage graft and slide tracheoplasty techniques.Methods: Twenty-nine patients underwent surgical repair of LCTS at 29 days to 9 years of age. In 26 patients, more than 50% of the entire length of the trachea was involved.

Chikara Tsugawa; Eiji Nishijima; Toshihiro Muraji; Shiiki Satoh; Shigeru Takamizawa; Masahiro Yamaguchi; Naoki Yoshimura; Shigeteru Oka; Ken Kimura

2003-01-01

370

Segmental analysis of molecular surface electrostatic potentials: application to enzyme inhibition  

Microsoft Academic Search

We have recently shown that the anti-HIV activities of reverse transcriptase inhibitors can be related quantitatively to properties\\u000a of the electrostatic potentials on their molecular surfaces. We now introduce the technique of using only segments of the\\u000a drug molecules in developing such expressions. If an improved correlation is obtained for a given family of compounds, it\\u000a would suggest that the

Tore Brinck; Ping Jin; Yuguang Ma; Jane S. Murray; Peter Politzer

2003-01-01

371

Sequence determination and functional analysis of the Akabane virus (family Bunyaviridae ) L RNA segment  

Microsoft Academic Search

Summary.  Akabane virus (AKAV) causes epizootic congenital deformities in cattle, sheep, and goats. Due to the lack of a complete genome\\u000a sequence, the molecular biological properties of this virus are not known. We have cloned and sequenced the functional large\\u000a (L) RNA segment of AKAV, and shown that it has polymerase activity using a minireplicon system with RNA polymerase I. The

Y. Ogawa; K. Kato; Y. Tohya; H. Akashi

2007-01-01

372

Congenital Aortic Disease: 4D Magnetic Resonance Segmentation and Quantitative Analysis  

PubMed Central

Automated and accurate segmentation of the aorta in 4D (3D+time) cardiovascular magnetic resonance (MR) image data is important for early detection of congenital aortic disease leading to aortic aneurysms and dissections. A computer-aided diagnosis method is reported that allows one to objectively identify subjects with connective tissue disorders from sixteen-phase 4D aortic MR images. Starting with a step of multi-view image registration, our automated segmentation method combines level-set and optimal surface segmentation algorithms in a single optimization process so that the final aortic surfaces in all 16 cardiac phases are determined. The resulting aortic lumen surface is registered with an aortic model followed by calculation of modal indices of aortic shape and motion. The modal indices reflect the differences of any individual aortic shape and motion from an average aortic behavior. A Support Vector Machine (SVM) classifier is used for the discrimination between normal and connective tissue disorder subjects. 4D MR image data sets acquired from 104 normal and connective tissue disorder MR datasets were used for development and performance evaluation of our method. The automated 4D segmentation resulted in accurate aortic surfaces in all 16 cardiac phases, covering the aorta from the aortic annulus to the diaphragm, yielding subvoxel accuracy with signed surface positioning errors of ?0.07 ± 1.16 voxel (?0.10 ± 2.05 mm). The computer aided diagnosis method distinguished between normal and connective tissue disorder subjects with a classification correctness of 90.4%.

Zhao, Fei; Zhang, Honghai; Wahle, Andreas; Thomas, Matthew T.; Stolpen, Alan H.; Scholz, Thomas D.; Sonka, Milan

2009-01-01

373

The effect of lead selection on traditional and heart rate–adjusted ST segment analysis in the detection of coronary artery disease during exercise testing  

Microsoft Academic Search

Several methods of heart rate–adjusted ST segment (ST\\/HR) analysis have been suggested to improve the diagnostic accuracy of exercise electrocardiography in the identification of coronary artery disease compared with traditional ST segment analysis. However, no comprehensive comparison of these methods on a lead-by-lead basis in all 12 electrocardographic leads has been reported. This article compares the diagnostic performance of ST\\/HR

Jari Viik; Rami Lehtinen; Väinö Turjanmaa; Kari Niemelä; Jaakko Malmivuo

1997-01-01

374

Segmental and positional effects on children's coda production: comparing evidence from perceptual judgments and acoustic analysis.  

PubMed

Children's early productions are highly variable. Findings from children's early productions of grammatical morphemes indicate that some of the variability is systematically related to segmental and phonological factors. Here, we extend these findings by assessing 2-year-olds' production of non-morphemic codas using both listener decisions and acoustic analyses. Results showed that utterance position and coda manner influence perception, in that more stop codas were perceived utterance-finally compared to utterance-medially but fricative codas were perceived equally across utterance positions. Acoustic analyses showed some convergence to listeners' perception in that there were more cues associated with stops utterance-finally compared to utterance-medially. However, there was some divergence between the two methods in that acoustic cues to coda segments were also present in the majority of cases where a coda was not perceived. These findings provide insight into both the nature of children's emerging phonological representations and the effectiveness of coda transcription across segment types. PMID:22876767

Theodore, Rachel M; Demuth, Katherine; Shattuck-Hufnagel, Stephanie

2012-09-01

375

A new high-resolution computed tomography (CT) segmentation method for trabecular bone architectural analysis.  

PubMed

In the last decade, high-resolution computed tomography (CT) and microcomputed tomography (micro-CT) have been increasingly used in anthropological studies and as a complement to traditional histological techniques. This is due in large part to the ability of CT techniques to nondestructively extract three-dimensional representations of bone structures. Despite prior studies employing CT techniques, no completely reliable method of bone segmentation has been established. Accurate preprocessing of digital data is crucial for measurement accuracy, especially when subtle structures such as trabecular bone are investigated. The research presented here is a new, reproducible, accurate, and fully automated computerized segmentation method for high-resolution CT datasets of fossil and recent cancellous bone: the Ray Casting Algorithm (RCA). We compare this technique with commonly used methods of image thresholding (i.e., the half-maximum height protocol and the automatic, adaptive iterative thresholding procedure). While the quality of the input images is crucial for conventional image segmentation, the RCA method is robust regarding the signal to noise ratio, beam hardening, ring artifacts, and blurriness. Tests with data of extant and fossil material demonstrate the superior quality of RCA compared with conventional thresholding procedures, and emphasize the need for careful consideration of optimal CT scanning parameters. PMID:19280676

Scherf, Heike; Tilgner, Rico

2009-09-01

376

Automatic nevi segmentation using adaptive mean shift filters and feature analysis  

NASA Astrophysics Data System (ADS)

A novel automatic method of segmenting nevi is explained and analyzed in this paper. The first step in nevi segmentation is to iteratively apply an adaptive mean shift filter to form clusters in the image and to remove noise. The goal of this step is to remove differences in skin intensity and hairs from the image, while still preserving the shape of nevi present on the skin. Each iteration of the mean shift filter changes pixel values to be a weighted average of pixels in its neighborhood. Some new extensions to the mean shift filter are proposed to allow for better segmentation of nevi from the skin. The kernel, that describes how the pixels in its neighborhood will be averaged, is adaptive; the shape of the kernel is a function of the local histogram. After initial clustering, a simple merging of clusters is done. Finally, clusters that are local minima are found and analyzed to determine which clusters are nevi. When this algorithm was compared to an assessment by an expert dermatologist, it showed a sensitivity rate and diagnostic accuracy of over 95% on the test set, for nevi larger than 1.5mm.

King, Michael A.; Lee, Tim K.; Atkins, M. Stella; McLean, David I.

2004-05-01

377

Textural analysis and structure-tracking for geological mapping: applications to sonar images from Endeavour Segment, Juan de Fuca Ridge  

Microsoft Academic Search

The volume of data collected by side-scan sonar during seafloor surveys has become larger and larger as the resolution of these systems has improved. As a result, new image processing techniques need to be developed to partly automate the interpretation of this increasing wealth of data. The first two steps in the geological analysis of a new image usually are

Ph. Blondel; J. C. Sempere; V. Robigou

1993-01-01

378

Effects of immersion on visual analysis of volume data.  

PubMed

Volume visualization has been widely used for decades for analyzing datasets ranging from 3D medical images to seismic data to paleontological data. Many have proposed using immersive virtual reality (VR) systems to view volume visualizations, and there is anecdotal evidence of the benefits of VR for this purpose. However, there has been very little empirical research exploring the effects of higher levels of immersion for volume visualization, and it is not known how various components of immersion influence the effectiveness of visualization in VR. We conducted a controlled experiment in which we studied the independent and combined effects of three components of immersion (head tracking, field of regard, and stereoscopic rendering) on the effectiveness of visualization tasks with two x-ray microscopic computed tomography datasets. We report significant benefits of analyzing volume data in an environment involving those components of immersion. We find that the benefits do not necessarily require all three components simultaneously, and that the components have variable influence on different task categories. The results of our study improve our understanding of the effects of immersion on perceived and actual task performance, and provide guidance on the choice of display systems to designers seeking to maximize the effectiveness of volume visualization applications. PMID:22402687

Laha, Bireswar; Sensharma, Kriti; Schiffbauer, James D; Bowman, Doug A

2012-04-01

379

Knowledge-based method for segmentation and analysis of lung boundaries in chest X-ray images.  

PubMed

We present a knowledge-based approach to segmentation and analysis of the lung boundaries in chest X-rays. Image edges are matched to an anatomical model of the lung boundary using parametric features. A modular system architecture was developed which incorporates the model, image processing routines, an inference engine and a blackboard. Edges associated with the lung boundary are automatically identified and abnormal features are reported. In preliminary testing on 14 images for a set of 18 detectable abnormalities, the system showed a sensitivity of 88% and a specificity of 95% when compared with assessment by an experienced radiologist. PMID:10098894

Brown, M S; Wilson, L S; Doust, B D; Gill, R W; Sun, C

380

Texture-based segmentation and analysis of emphysema depicted on CT images  

NASA Astrophysics Data System (ADS)

In this study we present a texture-based method of emphysema segmentation depicted on CT examination consisting of two steps. Step 1, a fractal dimension based texture feature extraction is used to initially detect base regions of emphysema. A threshold is applied to the texture result image to obtain initial base regions. Step 2, the base regions are evaluated pixel-by-pixel using a method that considers the variance change incurred by adding a pixel to the base in an effort to refine the boundary of the base regions. Visual inspection revealed a reasonable segmentation of the emphysema regions. There was a strong correlation between lung function (FEV1%, FEV1/FVC, and DLCO%) and fraction of emphysema computed using the texture based method, which were -0.433, -.629, and -0.527, respectively. The texture-based method produced more homogeneous emphysematous regions compared to simple thresholding, especially for large bulla, which can appear as speckled regions in the threshold approach. In the texture-based method, single isolated pixels may be considered as emphysema only if neighboring pixels meet certain criteria, which support the idea that single isolated pixels may not be sufficient evidence that emphysema is present. One of the strength of our complex texture-based approach to emphysema segmentation is that it goes beyond existing approaches that typically extract a single or groups texture features and individually analyze the features. We focus on first identifying potential regions of emphysema and then refining the boundary of the detected regions based on texture patterns.

Tan, Jun; Zheng, Bin; Wang, Xingwei; Lederman, Dror; Pu, Jiantao; Sciurba, Frank C.; Gur, David; Leader, J. Ken

2011-03-01

381

'INTELLIGENCE LED POLICING OR POLICING LED INTELLIGENCE?' Integrating Volume Crime Analysis into Policing  

Microsoft Academic Search

This paper explores the integration of volume crime analysis into policing. Based on qualitative research in two police forces, the paper outlines the importance of analysis for intelligence led policing. However, while the rhetoric of using analysis to target police activity is generally accepted, the practice is different. A poor understanding of analysis amongst police officers, and a lack of

NINA C OPE

2004-01-01

382

Segmentation of acute pyelonephritis area on kidney SPECT images using binary shape analysis  

NASA Astrophysics Data System (ADS)

Acute pyelonephritis is a serious disease in children that may result in irreversible renal scarring. The ability to localize the site of urinary tract infection and the extent of acute pyelonephritis has considerable clinical importance. In this paper, we are devoted to segment the acute pyelonephritis area from kidney SPECT images. A two-step algorithm is proposed. First, the original images are translated into binary versions by automatic thresholding. Then the acute pyelonephritis areas are located by finding convex deficiencies in the obtained binary images. This work gives important diagnosis information for physicians and improves the quality of medical care for children acute pyelonephritis disease.

Wu, Chia-Hsiang; Sun, Yung-Nien; Chiu, Nan-Tsing

1999-05-01

383

Space Propulsion Hazards Analysis Manual (SPHAM). Volume 1 (Final rept. 1 Jan 83-31 Dec 88).  

National Technical Information Service (NTIS)

This volume, the first of two volumes, of the Space Propulsion Hazards Analysis Manual (SPHAM) is a compilation of methods and data directed at hazards analysis and safety for space propulsion and associated vehicles, but broadly applicable to other envir...

D. L. Becker

1989-01-01

384

CONTROL VOLUME ANALYSIS OF FEED FLOW IN EXTRUDERS  

Microsoft Academic Search

The motion of the feed in a single-screw extruder is calculated with the use of a triangular control volume to determine the feed velocity and direction. A cylindrical coordinate system with a rotating screw is used to obtain torque, force, and energy balances needed to determine the developing stress (pressure) and temperature of the feed plug. The resulting equations can

Stephen J. Derezinski

385

Active Segmentation  

PubMed Central

The human visual system observes and understands a scene/image by making a series of fixations. Every fixation point lies inside a particular region of arbitrary shape and size in the scene which can either be an object or just a part of it. We define as a basic segmentation problem the task of segmenting that region containing the fixation point. Segmenting the region containing the fixation is equivalent to finding the enclosing contour- a connected set of boundary edge fragments in the edge map of the scene - around the fixation. This enclosing contour should be a depth boundary. We present here a novel algorithm that finds this bounding contour and achieves the segmentation of one object, given the fixation. The proposed segmentation framework combines monocular cues (color/intensity/texture) with stereo and/or motion, in a cue independent manner. The semantic robots of the immediate future will be able to use this algorithm to automatically find objects in any environment. The capability of automatically segmenting objects in their visual field can bring the visual processing to the next level. Our approach is different from current approaches. While existing work attempts to segment the whole scene at once into many areas, we segment only one image region, specifically the one containing the fixation point. Experiments with real imagery collected by our active robot and from the known databases 1 demonstrate the promise of the approach.

Mishra, Ajay; Aloimonos, Yiannis

2009-01-01

386

Elderly Needs Assessment Survey. Volume III: Combined Analysis of Needs and Services: Recommendations.  

National Technical Information Service (NTIS)

This third volume of a three - volume report on the results of a study conducted for the District of Columbia Office on Aging by the Bureau of Social Science Research provides an analysis of overlaps and gaps in the services available to meet the expresse...

G. S. Hamilton

1978-01-01

387

Automated segmentation and analysis of fluorescent in situ hybridization (FISH) signals in interphase nuclei of pap-smear specimens  

NASA Astrophysics Data System (ADS)

Interphase fluorescence in situ hybridization (FISH) technology is a potential and promising molecular imaging tool, which can be applied to screen and detect cervical cancer. However, manual FISH detection method is a subjective, tedious, and time-consuming process that results in a large inter-reader variability and possible detection error (in particular for heterogeneous cases). Automatic FISH image analysis aims to potentially improve detection efficiency and also produce more accurate and consistent results. In this preliminary study, a new computerized scheme is developed to automatically segment analyzable interaphase cells and detect FISH signals using digital fluorescence microscopic images acquired from Pap-smear specimens. First, due to the large intensity variations of the acquired interphase cells and overlapping cells, an iterative (multiple) threshold method and a feature-based classifier are applied to detect and segment all potentially analyzable interphase nuclei depicted on a single image frame. Second, a region labeling algorithm followed up a knowledge-based classifier is implemented to identify splitting and diffused FISH signals. Finally, each detected analyzable cell is classified as normal or abnormal based on the automatically counted number of FISH signals. To test the performance of this scheme, an image dataset involving 250 Pap-smear FISH image frames was collected and used in this study. The overall accuracy rate for segmenting analyzable interphase nuclei is 86.6% (360/424). The sensitivity and specificity for classifying abnormal and normal cells are 88.5% and 86.6%, respectively. The overall cell classification agreement rate between our scheme and a cytogeneticist is 86.6%. The testing results demonstrate the feasibility of applying this automated scheme in FISH image analysis.

Wang, Xingwei; Zheng, Bin; Li, Shibo; Zhang, Roy R.; Li, Yuhua; Mulvihill, John J.; Chen, Wei R.; Liu, Hong

2009-02-01

388

Using principal component analysis to enhance the generalized multifractal analysis approach to textural segmentation: Theory and application to microresistivity well logs  

NASA Astrophysics Data System (ADS)

We introduce a new method to perform textural segmentation by mean of generalized multifractal analysis. This method can be applied to any signal or measure, self-similar or not. The main idea is to expand the log-generating function ?q(x) on a collection of basis functions denoted by ?q,n(x). These functions are chosen to be the principal components of the collection of functions ?q(x) which is obtained from a sliding window analysis of a 1D-signal. This approach allows to represent texture with a minimal number of uncorrelated textural parameters. Significant improvements are obtained for the textural segmentation of dipmeter microresistivity well logs.

Saucier, Antoine; Muller, Jiri

2002-06-01

389

Comparing Market-segment-profitability Analysis with Department-Profitability Analysis as Hotel Marketing-decision Tools  

Microsoft Academic Search

Although marketing managers would appreciate financial data that more directly support their activities, the financial data generated by hotel accounting systems are aimed at apportioning department-related expenses and reflecting financial picture of overall operation. Given the industry’s increased focus on the profit generated by a given customer or market segment, a more useful form of financial data would allow hotel

Islam Karadag; Woo Gon Kim

2006-01-01

390

Risk factors for neovascular glaucoma after carbon ion radiotherapy of choroidal melanoma using dose-volume histogram analysis  

SciTech Connect

Purpose: To determine the risk factors for neovascular glaucoma (NVG) after carbon ion radiotherapy (C-ion RT) of choroidal melanoma. Methods and Materials: A total of 55 patients with choroidal melanoma were treated between 2001 and 2005 with C-ion RT based on computed tomography treatment planning. All patients had a tumor of large size or one located close to the optic disk. Univariate and multivariate analyses were performed to identify the risk factors of NVG for the following parameters; gender, age, dose-volumes of the iris-ciliary body and the wall of eyeball, and irradiation of the optic disk (ODI). Results: Neovascular glaucoma occurred in 23 patients and the 3-year cumulative NVG rate was 42.6 {+-} 6.8% (standard error), but enucleation from NVG was performed in only three eyes. Multivariate analysis revealed that the significant risk factors for NVG were V50{sub IC} (volume irradiated {>=}50 GyE to iris-ciliary body) (p = 0.002) and ODI (p = 0.036). The 3-year NVG rate for patients with V50{sub IC} {>=}0.127 mL and those with V50{sub IC} <0.127 mL were 71.4 {+-} 8.5% and 11.5 {+-} 6.3%, respectively. The corresponding rate for the patients with and without ODI were 62.9 {+-} 10.4% and 28.4 {+-} 8.0%, respectively. Conclusion: Dose-volume histogram analysis with computed tomography indicated that V50{sub IC} and ODI were independent risk factors for NVG. An irradiation system that can reduce the dose to both the anterior segment and the optic disk might be worth adopting to investigate whether or not incidence of NVG can be decreased with it.

Hirasawa, Naoki [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS), Chiba (Japan) and Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan)]. E-mail: naoki_h@nirs.go.jp; Tsuji, Hiroshi [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS), Chiba (Japan); Ishikawa, Hitoshi [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS), Chiba (Japan); Koyama-Ito, Hiroko [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS), Chiba (Japan); Kamada, Tadashi [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS), Chiba (Japan); Mizoe, Jun-Etsu [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS), Chiba (Japan); Ito, Yoshiyuki [Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Naganawa, Shinji [Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Ohnishi, Yoshitaka [Departments of Ophthalmology, Wakayama Medical University, Wakayama (Japan); Tsujii, Hirohiko [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS), Chiba (Japan)

2007-02-01

391

Analysis of layered assays and volume microarrays in stratified media.  

PubMed

Changing traditional microarray methods by using both sides of a substrate or stacking microarrays combined with optical sectioning enables the detection of more than one assay along the z-axis. Here we demonstrate two sided substrates, multilayer arrays with up to 5 substrates, and 2- and 3-dimensional antigen microarrays. By replacing standard substrates with multiple 30 ?m layers of glass or mica, high density multilayer and 3-dimensional volume arrays were created within a stratified medium. Although a decrease in fluorescence intensity with increasing number of substrate layers was observed together with a concomitant broadening of the axial resolution, quantitative results were obtained from this stratified system using calibrated intensities. Two- and three-dimensional antigen microarrays were generated via microcontact printing and detected as indirect immunoassays with quantum dot conjugated antibodies. Volume arrays were analysed by confocal laser scanning microscopy producing clear patterns, even when the assays were overlapped spatially. PMID:22911003

Ghafari, Homanaz; Hanley, Quentin S

2012-08-22

392

Review and Analysis of Oil Shale Technologies. Volume II. True in Situ Technology.  

National Technical Information Service (NTIS)

This volume is a technical review and economic analysis of current true in-situ shale technology. Three techniques involving different fracturing methods are compared. Key variables include air compression, drilling depth, drill hole diameter and pattern ...

C. K. Jee D. Nicholson J. D. White S. K. Bhatia

1977-01-01

393

Feasibility Analysis for the Center for Performing Arts, Orange County, California. Volume II. Appendices.  

National Technical Information Service (NTIS)

Volume II of the study shows in table form: analysis of traffic, parking and utilities; construction cost estimates; survey of selected performing arts facilities and sports facilities in the Southern California Basin and selected interviews conducted reg...

1977-01-01

394

Economic Analysis of Roadway Occupancy for Freeway Pavement Maintenance and Rehabilitation. Volume 2. Users Manual.  

National Technical Information Service (NTIS)

A computer program was developed to perform an Economic Analysis of Roadway Occupancy for Maintenance and Rehabilitation EAROMAR. The user specifies the pavement design and traffic. The program generates hourly traffic volume by trip purpose, direction an...

B. C. Butler

1974-01-01

395

Solvent-Based to Waterbased Adhesive-Coated Substrate Retrofit. Volume 1. Comparative Analysis.  

National Technical Information Service (NTIS)

This volume represents the analysis of case study facilities' experience with waterbased adhesive use and retrofit requirements. Chapter 2 describes the information-collection phase used to screen out facilities most appropriate for case study visits. Cha...

B. W. McMinn W. S. Snow D. T. Bowman

1996-01-01

396

The State of the City 1972. A Statistical Analysis of Community Characteristics. Volume I.  

National Technical Information Service (NTIS)

Criteria for subsystem modularity in the design of the urban information system are discussed. Fourteen subsystems of three types are identified in response to these criteria. Volume I explains the development of the Community Analysis Bureau, the scienti...

J. Mersel C. Avery R. Carlson S. Hoffman N. Minter

1973-01-01

397

Analysis of Liquid Volume and Liquid Mass Fractions at Coexistence for Pure Fluids.  

National Technical Information Service (NTIS)

An analysis of the behavior of liquid volume and liquid mass fractions at coexistence for pure fluids is made. Scaled equations for the saturation liquid and vapor densities are analyzed and relationships between various exponents and among constant coeff...

L. J. Van Poolen

1980-01-01

398

Evaluation of the Cost Effectiveness of Alternative Compensatory Reading Programs. Volume III: Cost-Effectiveness Analysis.  

National Technical Information Service (NTIS)

Measurements of the effectiveness of reading instruction are combined with cost data described in Volume I in a comparison of the cost effectiveness of elementary school reading programs. The measure of effectiveness used in the analysis is the residual g...

D. L. Flynn A. E. Hass N. Al-Salam

1976-01-01

399

Focal segmental glomerulosclerosis associated with maternally inherited diabetes and deafness: Clinical pathological analysis.  

PubMed

Maternally inherited diabetes and deafness (MIDD), which is caused by an A to G substitution at position 3243 (m.3243A>G) in the transfer ribonucleic acid leucine gene, is characterized by diabetes and hearing loss. Patients with MIDD frequently have renal disease, which may precede the diagnosis of either diabetes or deafness or may be the sole manifestation of the m.3243A>G mutation. Recently, progressive renal failure was reported in adults, and a number of childhood cases of focal segmental glomerulosclerosis (FSGS) of MIDD have been reported. However, little is known about the glomerular lesions in FSGS in MIDD. In the present study, we reported two cases of FSGS associated with MIDD and studied the clinical features of the proband and her mother. PMID:24152508

Cao, Xue-Ying; Wei, Ri-Bao; Wang, Yuan-Da; Zhang, Xue-Guang; Tang, Li; Chen, Xiang-Mei

400

Intraspecific phylogeography of the gopher tortoise, Gopherus polyphemus: RFLP analysis of amplified mtDNA segments.  

PubMed

The slow rate of mtDNA evolution in turtles poses a limitation on the levels of intraspecific variation detectable by conventional restriction fragment surveys. We examined mtDNA variation in the gopher tortoise (Gopherus polyphemus) using an alternative restriction assay, one in which PCR-amplified segments of the mitochondrial genome were digested with tetranucleotide-site endonucleases. Restriction fragment polymorphisms representing four amplified regions were analysed to evaluate population genetic structure among 112 tortoises throughout the species' range. Thirty-six haplotypes were identified, and three major geographical assemblages (Eastern, Western, and Mid-Florida) were resolved by UPGMA and parsimony analyses. Eastern and Western assemblages abut near the Apalachicola drainage, whereas the Mid-Florida assemblage appears restricted to the Brooksville Ridge. The Eastern/Western assemblage boundary is remarkably congruent with phylogeographic profiles for eight additional species from the south-eastern U.S., representing both freshwater and terrestrial realms. PMID:8564009

Osentoski, M F; Lamb, T

1995-12-01

401

In vivo analysis of hippocampal subfield atrophy in mild cognitive impairment via semi-automatic segmentation of T2-weighted MRI  

PubMed Central

The measurement of hippocampal volumes using MRI is a useful in-vivo biomarker for detection and monitoring of early Alzheimer’s Disease (AD), including during the amnestic Mild Cognitive Impairment (a-MCI) stage. The pathology underlying AD has regionally selective effects within the hippocampus. As such, we predict that hippocampal subfields are more sensitive in discriminating prodromal AD (i.e., a-MCI) from cognitively normal controls than whole hippocampal volumes, and attempt to demonstrate this using a semi-automatic method that can accurately segment hippocampal subfields. High-resolution coronal-oblique T2-weighted images of the hippocampal formation were acquired in 45 subjects (28 controls and 17 a-MCI (mean age: 69.5 ± 9.2; 70.2 ± 7.6)). CA1, CA2, CA3, and CA4/DG subfields, along with head and tail regions, were segmented using an automatic algorithm. CA1 and CA4/DG segmentations were manually edited. Whole hippocampal volumes were obtained from the subjects’ T1-weighted anatomical images. Automatic segmentation produced significant group differences in the following subfields: CA1 (left: p=0.001, right: p=0.038), CA4/DG (left: p=0.002, right: p=0.043), head (left: p=0.018, right: p=0.002), and tail (left: p=0.019). After manual correction, differences were increased in CA1 (left: p<0.001, right: p=0.002), and reduced in CA4/DG (left: p=0.029, right: p=0.221). Whole hippocampal volumes significantly differed bilaterally (left: p=0.028, right: p=0.009). This pattern of atrophy in a-MCI is consistent with the topography of AD pathology observed in postmortem studies, and corrected left CA1 provided stronger discrimination than whole hippocampal volume (p=0.03). These results suggest that semi-automatic segmentation of hippocampal subfields is efficient and may provide additional sensitivity beyond whole hippocampal volumes.

Pluta, John; Yushkevich, Paul; Das, Sandhitsu; Wolk, David

2012-01-01

402

Tandem configurations of variably duplicated segments of 22q11.2 confirmed by fiber-FISH analysis.  

PubMed

22q11.2 duplication syndrome has recently been established as a new syndrome manifesting broad clinical phenotypes including mental retardation. It is reciprocal to DiGeorge (DGS)/velo-cardio-facial syndrome (VCFS), in which the same portion of the chromosome is hemizygously deleted. Deletions and duplications of the 22q11.2 region are facilitated by the low-copy repeats (LCRs) flanking this region. In this study, we aimed to identify the directions of the duplicated segments of 22q11.2 to better understand the mechanism of chromosomal duplication. To achieve this aim, we accumulated samples from four patients with 22q11.2 duplications. One of the patients had an atypically small (741?kb) duplication of 22q11.2. The centromeric end of the breakpoint was on LCR22A, but the telomeric end was between LCR22A and B. Therefore, the duplicated segment did not include T-box 1 gene (TBX1), the gene primarily responsible for the DGS/VCFS. As this duplication was shared by the patient's healthy mother, this appears to be a benign copy-number variation rather than a disease-causing alteration. The other three patients showed 3.0 or 4.0?Mb duplications flanked by LCRs. The directions of the duplicated segments were investigated by fiber-fluorescence in situ hybridization analysis. All samples showed tandem configurations. These results support the hypothesized mechanism of non-allelic homologous recombination with flanking LCRs and add additional evidence that many interstitial duplications are aligned as tandem configurations. PMID:21866110

Shimojima, Keiko; Okamoto, Nobuhiko; Inazu, Tetsuya; Yamamoto, Toshiyuki

2011-08-25

403

Segmental hair analysis for 11-nor-??-tetrahydrocannabinol-9-carboxylic acid and the patterns of cannabis use.  

PubMed

Cannabis is the most widely abused drug in the world. The purpose of this study is to detect 11-nor-9-carboxy-??-tetrahydrocannabinol (THCCOOH) in segmental hair and to evaluate the patterns of cannabis use. We investigated the relationship between the concentrations of THCCOOH in hair and the self-reported use data and the route of administration. For this purpose, the hair samples were washed, digested with 1 mL of 1 M NaOH at 85°C for 30 min along with the internal standard, THCCOOH-d? (2.5 pg/mg) and extracted in 2 mL of n-hexane-ethyl acetate (9:1) twice after adding 1 mL of 0.1N sodium acetate buffer (pH = 4.5) and 200 µL of acetic acid. The organic extract was transferred and evaporated and the mixture was derivatized with 50 µL of pentafluoropropionic anhydride and 25 µL of pentafluoropropanol for 30 min at 70°C. Reconstituted final extract was injected into the gas chromatography-tandem mass spectrometer operating in the negative chemical ionization mode. In segmental hair analysis, the concentrations of THCCOOH decreased from the proximal to distal segments. The concentrations of THCCOOH in hair and the self-reported dose and frequency of administration from cannabis users were not well correlated because of the low accuracy and reliability of the self-reported data. However, this study provides preliminary information on the dose and frequency of administration among cannabis users in our country. PMID:22417835

Han, Eunyoung; Chung, Heesun; Song, Joon Myong

2012-04-01

404

Analysis and Design of a Deep Reservoir, High Volume Nitrogen Injection Project in the R-1 Sand, Lake Barre Field  

Microsoft Academic Search

An expansion of a low volume gas injection project in the R-1 Sand, Segment G in the Lake Barre Field, Louisiana, was investigated. Computer modeling shows that over five million barrels of oil can be produced. An evaluation of the future enhanced oil recovery alternatives of the reservoir was performed. Nitrogen injection was determined to be the only feasible method

James Haag

1981-01-01

405

Automatic segmentation and identification of solitary pulmonary nodules on follow-up CT scans based on local intensity structure analysis and non-rigid image registration  

NASA Astrophysics Data System (ADS)

This paper presents a novel method that can automatically segment solitary pulmonary nodule (SPN) and match such segmented SPNs on follow-up thoracic CT scans. Due to the clinical importance, a physician needs to find SPNs on chest CT and observe its progress over time in order to diagnose whether it is benign or malignant, or to observe the effect of chemotherapy for malignant ones using follow-up data. However, the enormous amount of CT images makes large burden tasks to a physician. In order to lighten this burden, we developed a method for automatic segmentation and assisting observation of SPNs in follow-up CT scans. The SPNs on input 3D thoracic CT scan are segmented based on local intensity structure analysis and the information of pulmonary blood vessels. To compensate lung deformation, we co-register follow-up CT scans based on an affine and a non-rigid registration. Finally, the matches of detected nodules are found from registered CT scans based on a similarity measurement calculation. We applied these methods to three patients including 14 thoracic CT scans. Our segmentation method detected 96.7% of SPNs from the whole images, and the nodule matching method found 83.3% correspondences from segmented SPNs. The results also show our matching method is robust to the growth of SPN, including integration/separation and appearance/disappearance. These confirmed our method is feasible for segmenting and identifying SPNs on follow-up CT scans.

Chen, Bin; Naito, Hideto; Nakamura, Yoshihiko; Kitasaka, Takayuki; Rueckert, Daniel; Honma, Hirotoshi; Takabatake, Hirotsugu; Mori, Masaki; Natori, Hiroshi; Mori, Kensaku

2011-03-01

406

TRACE trajectory analysis and orbit determination program. Volume 13: Square root information filtering and smoothing  

Microsoft Academic Search

The TRACE Trajectory Analysis and Orbit Determination Program is a general purpose orbital analysis program. It was developed specifically to assist technical personnel in the analysis and design of satellite orbits and tracking systems. Volume 13 is a technical reference for the square root information filtering and smoothing (SRIF\\/S) capabilities, which are used for high precision orbit determination and error

L. A. Campbell

1991-01-01

407

3D multiscale segmentation and morphological analysis of X-ray microtomography from cold-sprayed coatings.  

PubMed

X-ray microtomography from cold-sprayed coatings brings a new insight on this deposition process. A noise-tolerant segmentation algorithm is introduced, based on the combination of two segmentations: a deterministic multiscale segmentation and a stochastic segmentation. The stochastic approach uses random Poisson lines as markers. Results on a X-ray microtomographic image of aluminium particles are presented and validated. PMID:22946787

Gillibert, L; Peyrega, C; Jeulin, D; Guipont, V; Jeandin, M

2012-09-05

408

Synfuel program analysis. Volume 2: VENVAL users manual  

NASA Astrophysics Data System (ADS)

This volume is intended for program analysts and is a users manual for the VENVAL model. It contains specific explanations as to input data requirements and programming procedures for the use of this model. VENVAL is a generalized computer program to aid in evaluation of prospective private sector production ventures. The program can project interrelated values of installed capacity, production, sales revenue, operating costs, depreciation, investment, dent, earnings, taxes, return on investment, depletion, and cash flow measures. It can also compute related public sector and other external costs and revenues if unit costs are furnished.

Muddiman, J. B.; Whelan, J. W.

1980-07-01

409

Reliability and reproducibility of macular segmentation using a custom-built optical coherence tomography retinal image analysis software  

NASA Astrophysics Data System (ADS)

We determine the reliability and reproducibility of retinal thickness measurements with a custom-built OCT retinal image analysis software (OCTRIMA). Ten eyes of five healthy subjects undergo repeated standard macular thickness map scan sessions by two experienced examiners using a Stratus OCT device. Automatic/semi automatic thickness quantification of the macula and intraretinal layers is performed using OCTRIMA software. Intraobserver, interobserver, and intervisit repeatability and reproducibility coefficients, and intraclass correlation coefficients (ICCs) per scan are calculated. Intraobserver, interobserver, and intervisit variability combined account for less than 5% of total variability for the total retinal thickness measurements and less than 7% for the intraretinal layers except the outer segment/ retinal pigment epithelium (RPE) junction. There is no significant difference between scans acquired by different observers or during different visits. The ICCs obtained for the intraobserver and intervisit variability tests are greater than 0.75 for the total retina and all intraretinal layers, except the inner nuclear layer intraobserver and interobserver test and the outer plexiform layer, intraobserver, interobserver, and intervisit test. Our results indicate that thickness measurements for the total retina and all intraretinal layers (except the outer segment/RPE junction) performed using OCTRIMA are highly repeatable and reproducible.

Cabrera Debuc, Delia; Somfai, Gábor Márk; Ranganathan, Sudarshan; Tátrai, Erika; Ferencz, Mária; Puliafito, Carmen A.

2009-11-01

410

Detection of microcalcification clusters using Hessian matrix and foveal segmentation method on multiscale analysis in digital mammograms.  

PubMed

Mammography is the most efficient technique for detecting and diagnosing breast cancer. Clusters of microcalcifications have been mainly targeted as a reliable early sign of breast cancer and their earliest detection is essential to reduce the probability of mortality rate. Since the size of microcalcifications is very tiny and may be overlooked by the observing radiologist, we have developed a Computer Aided Diagnosis system for automatic and accurate cluster detection. A three-phased novel approach is presented in this paper. Firstly, regions of interest that corresponds to microcalcifications are identified. This can be achieved by analyzing the bandpass coefficients of the mammogram image. The suspicious regions are passed to the second phase, in which the nodular structured microcalcifications are detected based on eigenvalues of second order partial derivatives of the image and microcalcification pixels are segmented out by exploiting the foveal segmentation in multiscale analysis. Finally, by combining the responses coming out from the second order partial derivatives and the foveal method, potential microcalcifications are detected. The detection performance of the proposed method has been evaluated by using 370 mammograms. The detection method has a TP ratio of 97.76 % with 0.68 false positives per image. We have examined the performance of our computerized scheme using free-response operating characteristics curve. PMID:22581343

Thangaraju, Balakumaran; Vennila, Ila; Chinnasamy, Gowrishankar

2012-10-01

411

Determination of lead in hair and its segmental analysis by solid sampling electrothermal atomic absorption spectrometry  

NASA Astrophysics Data System (ADS)

A rapid and practical solid sampling electrothermal atomic absorption spectrometric method was described for the determination of lead in scalp hair. Hair samples were washed once with acetone; thrice with distilled-deionized water and again once with acetone and dried at 75 °C. Typically 0.05 to 1.0 mg of dried samples were inserted on the platforms of solid sampling autosampler. The effects of pyrolysis temperature, atomization temperature, the amount of sample as well as addition of a modifier (Pd/Mg) and/or auxiliary digesting agents (hydrogen peroxide and nitric acid) and/or a surfactant (Triton X-100) on the recovery of lead were investigated. Hair samples were washed once with acetone; thrice with distilled-deionized water and again once with acetone and dried at 75 °C. Typically 0.05 to 1.0 mg of dried samples were inserted on the platforms of solid sampling autosampler. The limit of detection for lead (3 ?, N = 10) was 0.3 ng/g The addition of modifier, acids, oxidant and surfactant hardly improved the results. Due to the risk of contamination and relatively high blank values, the lead in hair were determined directly without adding any reagent(s). Finally, the method was applied for the segmental determination of lead concentrations in hair of different persons which is important to know when and how much a person was exposed to the analyte. For this purpose, 0.5 cm of pieces were cut along the one or a few close strands and analyzed by solid sampling.

Baysal, Asli; Akman, Suleyman

2010-04-01

412

A detailed analysis of 16S ribosomal RNA gene segments for the diagnosis of pathogenic bacteria.  

PubMed Central

Bacterial 16S ribosomal RNA (rRNA) genes contain nine “hypervariable regions” (V1 – V9) that demonstrate considerable sequence diversity among different bacteria. Species-specific sequences within a given hypervariable region constitute useful targets for diagnostic assays and other scientific investigations. No single region can differentiate among all bacteria; therefore, systematic studies that compare the relative advantage of each region for specific diagnostic goals are needed. We characterized V1 - V8 in 110 different bacterial species including common blood borne pathogens, CDC-defined select agents and environmental microflora. Sequence similarity dendrograms were created for hypervariable regions V1 – V8, and for selected combinations of regions or short segments within individual hypervariable regions that might be appropriate for DNA probing and real-time PCR. We determined that V1 best differentiated among Staphylococcus aureus and coagulase negative Staphylococcus sp. V2 and V3 were most suitable for distinguishing all bacterial species to the genus level except for closely related enterobacteriaceae. V2 best distinguished among Mycobacterial species and V3 among Haemophilus species. The 58 nucleotides-long V6 could distinguish among most bacterial species except enterobacteriaceae. V6 was also noteworthy for being able to differentiate among all CDC-defined select agents including Bacillus anthracis, which differed from B. cereus by a single polymorphism. V4, V5, V7 and V8 were less useful targets for genus or species-specific probes. The hypervariable sequence-specific dendrograms and the “MEGALIGN” files provided online will be highly useful tools for designing specific probes and primers for molecular assays to detect pathogenic bacteria, including select agents.

Chakravorty, Soumitesh; Helb, Danica; Burday, Michele; Connell, Nancy; Alland, David

2007-01-01

413

Ventriculogram segmentation using boosted decision trees  

NASA Astrophysics Data System (ADS)

Left ventricular status, reflected in ejection fraction or end systolic volume, is a powerful prognostic indicator in heart disease. Quantitative analysis of these and other parameters from ventriculograms (cine xrays of the left ventricle) is infrequently performed due to the labor required for manual segmentation. None of the many methods developed for automated segmentation has achieved clinical acceptance. We present a method for semi-automatic segmentation of ventriculograms based on a very accurate two-stage boosted decision-tree pixel classifier. The classifier determines which pixels are inside the ventricle at key ED (end-diastole) and ES (end-systole) frames. The test misclassification rate is about 1%. The classifier is semi-automatic, requiring a user to select 3 points in each frame: the endpoints of the aortic valve and the apex. The first classifier stage is 2 boosted decision-trees, trained using features such as gray-level statistics (e.g. median brightness) and image geometry (e.g. coordinates relative to user supplied 3 points). Second stage classifiers are trained using the same features as the first, plus the output of the first stage. Border pixels are determined from the segmented images using dilation and erosion. A curve is then fit to the border pixels, minimizing a penalty function that trades off fidelity to the border pixels with smoothness. ED and ES volumes, and ejection fraction are estimated from border curves using standard area-length formulas. On independent test data, the differences between automatic and manual volumes (and ejection fractions) are similar in size to the differences between two human observers.

McDonald, John A.; Sheehan, Florence H.

2004-05-01

414

Enhanced cardiac thermal dilution analysis for cardiac output, volumes, stroke volumes, and regurgitation rates--sensitivity analysis using digital simulation.  

PubMed

Cardiac output is measured by placing a double lumen catheter with a thermistor on the tip through the right ventricle into the pulmonary artery, injecting cold saline into the right atrium, and integrating the resulting pulmonary artery temperature profile. If a similar procedure is performed with thermistors located in the right atrium, right ventricle, and pulmonary artery, the resulting temperature curves are determined by the known or easily measured quantities: injectate temperature, injectate volume, heart rate, systolic time interval, body temperature, and time in the cardiac cycle at which injection begins and the unknown quantities: right atrial, right ventricular, pulmonary artery mean and stroke volumes, inflow and outflow valve regurgitation rates, and cardiac output. A digital computer program using a lumped parameter model has been developed to use these quantities to produce thermal dilution curves and optimize the fit of the model curves to the temperature curves from the thermal dilution measurement to determine the unknown quantities. The program is used to investigate the effects of measuring system time constant, heat transfer, and noise on the accuracy of these measurements. The results indicate that the method is practical. PMID:10999367

Donovan, F M; Taylor, B C

2000-01-01

415

Comparative Study of Adaptive Segmentation Techniques for Gesture Analysis in Unconstrained Environments  

Microsoft Academic Search

This paper discusses the importance of providing non- invasive techniques in the analysis of the complex movements performed by musicians and athletes. Current gesture analysis systems are insufficient and do not succeed in providing quality performance measurements without imposing strict environmental and operational constraints on individuals. Computer vision offers the means with which such techniques can be made possible without

Martin Côté; Pierre Payeur; Gilles Comeau

2006-01-01

416

TEXTURE ANALYSIS FOR CLASSIFICATION AND SEGMENTATION OF AIRBORNE IMAGES OF PLANT COVER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Image texture is an element of the spatial information domain of remote sensing information. Image texture analysis is a useful tool that can provide complementary information to spectral data analysis. Crops and natural ecosystem plants have different quantitative texture characteristics that off...

417

Design and validation of Segment - freely available software for cardiovascular image analysis  

Microsoft Academic Search

BACKGROUND: Commercially available software for cardiovascular image analysis often has limited functionality and frequently lacks the careful validation that is required for clinical studies. We have already implemented a cardiovascular image analysis software package and released it as freeware for the research community. However, it was distributed as a stand-alone application and other researchers could not extend it by writing

Einar Heiberg; Jane Sjögren; Martin Ugander; Marcus Carlsson; Henrik Engblom; Håkan Arheden

2010-01-01

418

Left ventricular pressure and volume data acquisition and analysis using LabVIEW.  

PubMed

To automate analysis of left ventricular pressure-volume data, we used LabVIEW to create applications that digitize and display data recorded from conductance and manometric catheters. Applications separate data into cardiac cycles, calculate parallel conductance, and calculate indices of left ventricular function, including end-systolic elastance, preload-recruitable stroke work, stroke volume, ejection fraction, stroke work, maximum and minimum derivative of ventricular pressure, heart rate, indices of relaxation, peak filling rate, and ventricular chamber stiffness. Pressure-volume loops can be graphically displayed. These analyses are exported to a text-file. These applications have simplified and automated the process of evaluating ventricular function. PMID:9158920

Cassidy, S C; Teitel, D F

1997-03-01

419

Underground Test Area Subproject Phase I Data Analysis Task. Volume IV - Hydrologic Parameter Data Documentation Package  

SciTech Connect

Volume IV of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the hydrologic parameter data. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

None

1996-09-01

420

Underground Test Area Subproject Phase I Data Analysis Task. Volume VI - Groundwater Flow Model Documentation Package  

SciTech Connect

Volume VI of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the groundwater flow model data. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

None

1996-11-01

421

Underground Test Area Subproject Phase I Data Analysis Task. Volume VIII - Risk Assessment Documentation Package  

SciTech Connect

Volume VIII of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the risk assessment documentation. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

None

1996-12-01