18 results on '"C. Tanougast"'
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2. Banc d’instrumentation pour la mesure de l’influence de l’état de charge d’une batterie Li-ion
- Author
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L. Cicero, C. Tanougast, H. Ramenah, P. Jean, F. Lecerf, P. Milhas, and A. Dandache
- Published
- 2020
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3. Small Wind Power Energy Output Prediction in a Complex Zone upon Five Years Experimental Data
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MM, Ba, primary, Harry, Ramenah, additional, and C, Tanougast, additional
- Published
- 2017
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4. Experimental performance of mobile DVB-T2 in SFN and distributed MISO network
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M. Tormos, C. Tanougast, A. Dandache, P. Bretillon, and P. Kasser
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business.industry ,Computer science ,Mobile computing ,Single-frequency network ,DVB-T2 ,Digital multimedia broadcasting ,Modulation ,Digital Video Broadcasting ,Electronic engineering ,Digital television ,Mobile telephony ,business ,Multipath propagation ,Computer network - Abstract
Digital Video Broadcasting-Handheld (DVB-H) and Terrestrial Digital Multimedia Broadcasting (T-DMB) are the most known standards that enable digital television transmissions to handheld or mobile receivers in Europe. The emerging DVB-T2 standard enables a network based on frequency diversity coding (called Alamouti Space-Frequency coding) suitable for multipath propagation environments which presents better performances for fixed reception compared to SFN (Single Frequency Network). In this paper, we present detailed experimental performance results of classical mobile channel (TU6) for DVB-T2. These evaluations are given for different Doppler frequencies in a classical SFN (Single Frequency Network) compared to distributed MISO. Laboratory and field measurements are presented. With the receiver used for our experiments, the results show clearly the quality degradation of received signals for distributed MISO compared to classic SFN. These results are useful for the study and the determination of the current mobile performance of DVB-T2 and network design and may also be useful for upcoming standards such as DVB-NGH (Next Generation Handheld).
- Published
- 2012
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5. Performance evaluation of distributed Tarokh SFBC and Alamouti MISO for SFN DVB-T2 broadcast networks
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M. Tormos, C. Tanougast, A. Dandache, P. Bretillon, and P. Kasser
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Block code ,Computer science ,Orthogonal frequency-division multiplexing ,Digital Video Broadcasting ,Electronic engineering ,Single-frequency network ,Low-density parity-check code ,BCH code ,DVB-T2 ,Diversity scheme - Abstract
In this paper, we evaluate the performances of distributed Tarokh Space Frequency Block Coding (SFBC) compared to classical Single Frequency Network (SFN) and Distributed Alamouti MISO with SFN (MISO-SFN) for the emerging second generation digital TV Broadcasting (DVB-T2). We showed the performance of SFN and Alamouti MISO-SFN for two, three and four transmitters for DVB-T2 chain. We also compared the performances of distributed Tarokh MISO compared to SFN and Alamouti MISO-SFN for three transmitters in OFDM transmission with LDPC and BCH coding to be similar as DVB-T2 chain. The results showed clearly that the distributed Tarokh diversity can be used to improve the DVB-T2 network of three antennas and more.
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- 2011
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6. Can Autism Be Diagnosed with Artificial Intelligence? A Narrative Review.
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Chaddad A, Li J, Lu Q, Li Y, Okuwobi IP, Tanougast C, Desrosiers C, and Niazi T
- Abstract
Radiomics with deep learning models have become popular in computer-aided diagnosis and have outperformed human experts on many clinical tasks. Specifically, radiomic models based on artificial intelligence (AI) are using medical data (i.e., images, molecular data, clinical variables, etc.) for predicting clinical tasks such as autism spectrum disorder (ASD). In this review, we summarized and discussed the radiomic techniques used for ASD analysis. Currently, the limited radiomic work of ASD is related to the variation of morphological features of brain thickness that is different from texture analysis. These techniques are based on imaging shape features that can be used with predictive models for predicting ASD. This review explores the progress of ASD-based radiomics with a brief description of ASD and the current non-invasive technique used to classify between ASD and healthy control (HC) subjects. With AI, new radiomic models using the deep learning techniques will be also described. To consider the texture analysis with deep CNNs, more investigations are suggested to be integrated with additional validation steps on various MRI sites.
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- 2021
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7. Asymmetric optical cryptosystem for multiple images based on devil's spiral Fresnel lens phase and random spiral transform in gyrator domain.
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Chen H, Liu Z, Tanougast C, and Blondel W
- Abstract
An asymmetric cryptosystem is presented for encrypting multiple images in gyrator transform domains. In the encryption approach, the devil's spiral Fresnel lens variable pure phase mask is first designed for each image band to be encrypted by using devil' mask, random spiral phase and Fresnel mask, respectively. Subsequently, a novel random devil' spiral Fresnel transform in optical gyrator transform is implemented to achieved the intermediate output. Then, the intermediate data is divided into two masks by employing random modulus decomposition in the asymmetric process. Finally, a random permutation matrix is utilized to obtain the ciphertext of the intact algorithm. For the decryption approach, two divided masks (private key and ciphertext) need to be imported into the optical gyrator input plane simultaneously. Some numerical experiments are given to verify the effectiveness and capability of this asymmetric cryptosystem., (© 2021. The Author(s).)
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- 2021
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8. Author Correction: Dual paths cryptosystem based on tilt Fresnel diffraction using non-spherical mirror and phase modulation in expanded fractional Fourier transform domain.
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Chen H, Liu Z, Tanougast C, Liu F, and Blondel W
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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- 2020
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9. Dual paths cryptosystem based on tilt Fresnel diffraction using non-spherical mirror and phase modulation in expanded fractional Fourier transform domain.
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Chen H, Liu Z, Tanougast C, Liu F, and Blondel W
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In this paper, a dual optics paths optical image cryptosystem based on tilt Fresnel diffraction and a phase modulation in extend fractional Fourier transform (eFrFT) domain is presented. The tilt Fresnel is designed by using a non-spherical mirror. A part of data from the original image is modulated by the mirror, while the other part is encoded by an expanded fractional Fourier transform. Besides, the random data of the dual channels is combined for forming the encrypted image. The structure parameters in designing the optical hardware system and the random phase can be regarded as decryption keys. Various potential attack experiments are implemented to check the validity of the proposed cryptographic system.
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- 2019
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10. Hippocampus and amygdala radiomic biomarkers for the study of autism spectrum disorder.
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Chaddad A, Desrosiers C, Hassan L, and Tanougast C
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- Adolescent, Area Under Curve, Autism Spectrum Disorder diagnostic imaging, Biomarkers analysis, Child, Child, Preschool, Female, Humans, Magnetic Resonance Imaging methods, Male, Sensitivity and Specificity, Amygdala physiopathology, Autism Spectrum Disorder physiopathology, Hippocampus physiopathology, Image Processing, Computer-Assisted methods
- Abstract
Background: Emerging evidence suggests the presence of neuroanatomical abnormalities in subjects with autism spectrum disorder (ASD). Identifying anatomical correlates could thus prove useful for the automated diagnosis of ASD. Radiomic analyses based on MRI texture features have shown a great potential for characterizing differences occurring from tissue heterogeneity, and for identifying abnormalities related to these differences. However, only a limited number of studies have investigated the link between image texture and ASD. This paper proposes the study of texture features based on grey level co-occurrence matrix (GLCM) as a means for characterizing differences between ASD and development control (DC) subjects. Our study uses 64 T1-weighted MRI scans acquired from two groups of subjects: 28 typical age range subjects 4-15 years old (14 ASD and 14 DC, age-matched), and 36 non-typical age range subjects 10-24 years old (20 ASD and 16 DC). GLCM matrices are computed from manually labeled hippocampus and amygdala regions, and then encoded as texture features by applying 11 standard Haralick quantifier functions. Significance tests are performed to identify texture differences between ASD and DC subjects. An analysis using SVM and random forest classifiers is then carried out to find the most discriminative features, and use these features for classifying ASD from DC subjects., Results: Preliminary results show that all 11 features derived from the hippocampus (typical and non-typical age) and 4 features extracted from the amygdala (non-typical age) have significantly different distributions in ASD subjects compared to DC subjects, with a significance of p < 0.05 following Holm-Bonferroni correction. Features derived from hippocampal regions also demonstrate high discriminative power for differentiating between ASD and DC subjects, with classifier accuracy of 67.85%, sensitivity of 62.50%, specificity of 71.42%, and the area under the ROC curve (AUC) of 76.80% for age-matched subjects with typical age range., Conclusions: Results demonstrate the potential of hippocampal texture features as a biomarker for the diagnosis and characterization of ASD.
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- 2017
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11. Classifications of Multispectral Colorectal Cancer Tissues Using Convolution Neural Network.
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Haj-Hassan H, Chaddad A, Harkouss Y, Desrosiers C, Toews M, and Tanougast C
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Background: Colorectal cancer (CRC) is the third most common cancer among men and women. Its diagnosis in early stages, typically done through the analysis of colon biopsy images, can greatly improve the chances of a successful treatment. This paper proposes to use convolution neural networks (CNNs) to predict three tissue types related to the progression of CRC: benign hyperplasia (BH), intraepithelial neoplasia (IN), and carcinoma (Ca)., Methods: Multispectral biopsy images of thirty CRC patients were retrospectively analyzed. Images of tissue samples were divided into three groups, based on their type (10 BH, 10 IN, and 10 Ca). An active contour model was used to segment image regions containing pathological tissues. Tissue samples were classified using a CNN containing convolution, max-pooling, and fully-connected layers. Available tissue samples were split into a training set, for learning the CNN parameters, and test set, for evaluating its performance., Results: An accuracy of 99.17% was obtained from segmented image regions, outperforming existing approaches based on traditional feature extraction, and classification techniques., Conclusions: Experimental results demonstrate the effectiveness of CNN for the classification of CRC tissue types, in particular when using presegmented regions of interest., Competing Interests: There are no conflicts of interest.
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- 2017
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12. Texture Analysis of Abnormal Cell Images for Predicting the Continuum of Colorectal Cancer.
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Chaddad A and Tanougast C
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- Colon pathology, Colorectal Neoplasms pathology, Humans, Precancerous Conditions pathology, Principal Component Analysis, ROC Curve, Rectum pathology, Reproducibility of Results, Algorithms, Colon diagnostic imaging, Colorectal Neoplasms diagnostic imaging, Image Processing, Computer-Assisted methods, Precancerous Conditions diagnostic imaging, Rectum diagnostic imaging
- Abstract
Abnormal cell (ABC) is a markedly heterogeneous tissue area and can be categorized into three main types: benign hyperplasia (BH), carcinoma (Ca), and intraepithelial neoplasia (IN) or precursor cancerous lesion. In this study, the goal is to determine and characterize the continuum of colorectal cancer by using a 3D-texture approach. ABC was segmented in preprocessing step using an active contour segmentation technique. Cell types were analyzed based on textural features extracted from the gray level cooccurrence matrices (GLCMs). Significant texture features were selected using an analysis of variance (ANOVA) of ABC with a p value cutoff of p < 0.01. Features selected were reduced with a principal component analysis (PCA), which accounted for 97% of the cumulative variance from significant features. The simulation results identified 158 significant features based on ANOVA from a total of 624 texture features extracted from GLCMs. Performance metrics of ABC discrimination based on significant texture features showed 92.59% classification accuracy, 100% sensitivity, and 94.44% specificity. These findings suggest that texture features extracted from GLCMs are sensitive enough to discriminate between the ABC types and offer the opportunity to predict cell characteristics of colorectal cancer., Competing Interests: The authors declare that there is no conflict of interests regarding the publication of this paper.
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- 2017
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13. A quantitative study of shape descriptors from glioblastoma multiforme phenotypes for predicting survival outcome.
- Author
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Chaddad A, Desrosiers C, Hassan L, and Tanougast C
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- Adolescent, Adult, Aged, Aged, 80 and over, Area Under Curve, Brain diagnostic imaging, Evaluation Studies as Topic, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, ROC Curve, Reproducibility of Results, Survival Analysis, Young Adult, Brain Neoplasms diagnostic imaging, Glioblastoma diagnostic imaging, Image Interpretation, Computer-Assisted methods
- Abstract
Objective: Predicting the survival outcome of patients with glioblastoma multiforme (GBM) is of key importance to clinicians for selecting the optimal course of treatment. The goal of this study was to evaluate the usefulness of geometric shape features, extracted from MR images, as a potential non-invasive way to characterize GBM tumours and predict the overall survival times of patients with GBM., Methods: The data of 40 patients with GBM were obtained from the Cancer Genome Atlas and Cancer Imaging Archive. The T
1 weighted post-contrast and fluid-attenuated inversion-recovery volumes of patients were co-registered and segmented into delineate regions corresponding to three GBM phenotypes: necrosis, active tumour and oedema/invasion. A set of two-dimensional shape features were then extracted slicewise from each phenotype region and combined over slices to describe the three-dimensional shape of these phenotypes. Thereafter, a Kruskal-Wallis test was employed to identify shape features with significantly different distributions across phenotypes. Moreover, a Kaplan-Meier analysis was performed to find features strongly associated with GBM survival. Finally, a multivariate analysis based on the random forest model was used for predicting the survival group of patients with GBM., Results: Our analysis using the Kruskal-Wallis test showed that all but one shape feature had statistically significant differences across phenotypes, with p-value < 0.05, following Holm-Bonferroni correction, justifying the analysis of GBM tumour shapes on a per-phenotype basis. Furthermore, the survival analysis based on the Kaplan-Meier estimator identified three features derived from necrotic regions (i.e. Eccentricity, Extent and Solidity) that were significantly correlated with overall survival (corrected p-value < 0.05; hazard ratios between 1.68 and 1.87). In the multivariate analysis, features from necrotic regions gave the highest accuracy in predicting the survival group of patients, with a mean area under the receiver-operating characteristic curve (AUC) of 63.85%. Combining the features of all three phenotypes increased the mean AUC to 66.99%, suggesting that shape features from different phenotypes can be used in a synergic manner to predict GBM survival., Conclusion: Results show that shape features, in particular those extracted from necrotic regions, can be used effectively to characterize GBM tumours and predict the overall survival of patients with GBM. Advances in knowledge: Simple volumetric features have been largely used to characterize the different phenotypes of a GBM tumour (i.e. active tumour, oedema and necrosis). This study extends previous work by considering a wide range of shape features, extracted in different phenotypes, for the prediction of survival in patients with GBM.- Published
- 2016
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14. Extracted magnetic resonance texture features discriminate between phenotypes and are associated with overall survival in glioblastoma multiforme patients.
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Chaddad A and Tanougast C
- Subjects
- Adult, Aged, Aged, 80 and over, Humans, Kaplan-Meier Estimate, Middle Aged, Phenotype, ROC Curve, Survival Analysis, Algorithms, Glioblastoma pathology, Magnetic Resonance Imaging methods
- Abstract
GBM is a markedly heterogeneous brain tumor consisting of three main volumetric phenotypes identifiable on magnetic resonance imaging: necrosis (vN), active tumor (vAT), and edema/invasion (vE). The goal of this study is to identify the three glioblastoma multiforme (GBM) phenotypes using a texture-based gray-level co-occurrence matrix (GLCM) approach and determine whether the texture features of phenotypes are related to patient survival. MR imaging data in 40 GBM patients were analyzed. Phenotypes vN, vAT, and vE were segmented in a preprocessing step using 3D Slicer for rigid registration by T1-weighted imaging and corresponding fluid attenuation inversion recovery images. The GBM phenotypes were segmented using 3D Slicer tools. Texture features were extracted from GLCM of GBM phenotypes. Thereafter, Kruskal-Wallis test was employed to select the significant features. Robust predictive GBM features were identified and underwent numerous classifier analyses to distinguish phenotypes. Kaplan-Meier analysis was also performed to determine the relationship, if any, between phenotype texture features and survival rate. The simulation results showed that the 22 texture features were significant with p value <0.05. GBM phenotype discrimination based on texture features showed the best accuracy, sensitivity, and specificity of 79.31, 91.67, and 98.75 %, respectively. Three texture features derived from active tumor parts: difference entropy, information measure of correlation, and inverse difference were statistically significant in the prediction of survival, with log-rank p values of 0.001, 0.001, and 0.008, respectively. Among 22 features examined, three texture features have the ability to predict overall survival for GBM patients demonstrating the utility of GLCM analyses in both the diagnosis and prognosis of this patient population.
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- 2016
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15. Quantitative evaluation of robust skull stripping and tumor detection applied to axial MR images.
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Chaddad A and Tanougast C
- Abstract
To isolate the brain from non-brain tissues using a fully automatic method may be affected by the presence of radio frequency non-homogeneity of MR images (MRI), regional anatomy, MR sequences, and the subjects of the study. In order to automate the brain tumor (Glioblastoma) detection, we proposed a novel approach of skull stripping for axial slices derived from MRI. Then, the brain tumor was detected using multi-level threshold segmentation based on histogram analysis. Skull-stripping method, was applied by adaptive morphological operations approach. This is considered an empirical threshold by calculation of the area of brain tissue, iteratively. It was employed on the registration of non-contrast T1-weighted (T1-WI) and its corresponding fluid attenuated inversion recovery sequence. Then, we used multi-thresholding segmentation (MTS) method which is proposed by Otsu. We calculated the performance metrics based on the similarity coefficients for patients (n = 120) with tumor. The adaptive algorithm of skull stripping and MTS of segmented tumors were achieved efficient in preliminary results with 92 and 80 % of Dice similarity coefficient and 0.3 and 25.8 % of false negative rate, respectively. The adaptive skull stripping algorithm provides robust skull-stripping results, and the tumor area for medical diagnosis was determined by MTS., Competing Interests: The authors declare that they have no competing interests.
- Published
- 2016
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16. Smart greenhouse fuzzy logic based control system enhanced with wireless data monitoring.
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Azaza M, Tanougast C, Fabrizio E, and Mami A
- Abstract
Greenhouse climate control is complicated procedure since the number of variables involved on it and which are dependent on each other. This paper presents a contribution to integrate greenhouse inside climate key's parameters, leading to promote a comfortable micro-climate for the plants growth while saving energy and water resources. A smart fuzzy logic based control system was introduced and improved through specific measure to the temperature and humidity correlation. As well, the system control was enhanced with wireless data monitoring platform for data routing and logging, which provides real time data access. The proposed control system was experimentally validated. The efficiency of the system was evaluated showing important energy and water saving., (Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2016
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17. Multi Texture Analysis of Colorectal Cancer Continuum Using Multispectral Imagery.
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Chaddad A, Desrosiers C, Bouridane A, Toews M, Hassan L, and Tanougast C
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- Humans, Image Processing, Computer-Assisted, In Vitro Techniques, Colorectal Neoplasms pathology, Diagnostic Imaging
- Abstract
Purpose: This paper proposes to characterize the continuum of colorectal cancer (CRC) using multiple texture features extracted from multispectral optical microscopy images. Three types of pathological tissues (PT) are considered: benign hyperplasia, intraepithelial neoplasia and carcinoma., Materials and Methods: In the proposed approach, the region of interest containing PT is first extracted from multispectral images using active contour segmentation. This region is then encoded using texture features based on the Laplacian-of-Gaussian (LoG) filter, discrete wavelets (DW) and gray level co-occurrence matrices (GLCM). To assess the significance of textural differences between PT types, a statistical analysis based on the Kruskal-Wallis test is performed. The usefulness of texture features is then evaluated quantitatively in terms of their ability to predict PT types using various classifier models., Results: Preliminary results show significant texture differences between PT types, for all texture features (p-value < 0.01). Individually, GLCM texture features outperform LoG and DW features in terms of PT type prediction. However, a higher performance can be achieved by combining all texture features, resulting in a mean classification accuracy of 98.92%, sensitivity of 98.12%, and specificity of 99.67%., Conclusions: These results demonstrate the efficiency and effectiveness of combining multiple texture features for characterizing the continuum of CRC and discriminating between pathological tissues in multispectral images.
- Published
- 2016
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18. High-Throughput Quantification of Phenotype Heterogeneity Using Statistical Features.
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Chaddad A and Tanougast C
- Abstract
Statistical features are widely used in radiology for tumor heterogeneity assessment using magnetic resonance (MR) imaging technique. In this paper, feature selection based on decision tree is examined to determine the relevant subset of glioblastoma (GBM) phenotypes in the statistical domain. To discriminate between active tumor (vAT) and edema/invasion (vE) phenotype, we selected the significant features using analysis of variance (ANOVA) with p value < 0.01. Then, we implemented the decision tree to define the optimal subset features of phenotype classifier. Naïve Bayes (NB), support vector machine (SVM), and decision tree (DT) classifier were considered to evaluate the performance of the feature based scheme in terms of its capability to discriminate vAT from vE. Whole nine features were statistically significant to classify the vAT from vE with p value < 0.01. Feature selection based on decision tree showed the best performance by the comparative study using full feature set. The feature selected showed that the two features Kurtosis and Skewness achieved a highest range value of 58.33-75.00% accuracy classifier and 73.88-92.50% AUC. This study demonstrated the ability of statistical features to provide a quantitative, individualized measurement of glioblastoma patient and assess the phenotype progression.
- Published
- 2015
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