Search

Your search keyword '"Nguyen, Mai K."' showing total 180 results
Start Over Author "Nguyen, Mai K."
180 results on '"Nguyen, Mai K."'

1. UnWave-Net: Unrolled Wavelet Network for Compton Tomography Image Reconstruction

Author

Ayad, Ishak, Tarpau, Cécilia, Cebeiro, Javier, and Nguyen, Maï K.

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition
Abstract

Computed tomography (CT) is a widely used medical imaging technique to scan internal structures of a body, typically involving collimation and mechanical rotation. Compton scatter tomography (CST) presents an interesting alternative to conventional CT by leveraging Compton physics instead of collimation to gather information from multiple directions. While CST introduces new imaging opportunities with several advantages such as high sensitivity, compactness, and entirely fixed systems, image reconstruction remains an open problem due to the mathematical challenges of CST modeling. In contrast, deep unrolling networks have demonstrated potential in CT image reconstruction, despite their computationally intensive nature. In this study, we investigate the efficiency of unrolling networks for CST image reconstruction. To address the important computational cost required for training, we propose UnWave-Net, a novel unrolled wavelet-based reconstruction network. This architecture includes a non-local regularization term based on wavelets, which captures long-range dependencies within images and emphasizes the multi-scale components of the wavelet transform. We evaluate our approach using a CST of circular geometry which stays completely static during data acquisition, where UnWave-Net facilitates image reconstruction in the absence of a specific reconstruction formula. Our method outperforms existing approaches and achieves state-of-the-art performance in terms of SSIM and PSNR, and offers an improved computational efficiency compared to traditional unrolling networks., Comment: This paper has been early accepted by MICCAI 2024

Published
2024

2. QN-Mixer: A Quasi-Newton MLP-Mixer Model for Sparse-View CT Reconstruction

Author

Ayad, Ishak, Larue, Nicolas, and Nguyen, Maï K.

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition
Abstract

Inverse problems span across diverse fields. In medical contexts, computed tomography (CT) plays a crucial role in reconstructing a patient's internal structure, presenting challenges due to artifacts caused by inherently ill-posed inverse problems. Previous research advanced image quality via post-processing and deep unrolling algorithms but faces challenges, such as extended convergence times with ultra-sparse data. Despite enhancements, resulting images often show significant artifacts, limiting their effectiveness for real-world diagnostic applications. We aim to explore deep second-order unrolling algorithms for solving imaging inverse problems, emphasizing their faster convergence and lower time complexity compared to common first-order methods like gradient descent. In this paper, we introduce QN-Mixer, an algorithm based on the quasi-Newton approach. We use learned parameters through the BFGS algorithm and introduce Incept-Mixer, an efficient neural architecture that serves as a non-local regularization term, capturing long-range dependencies within images. To address the computational demands typically associated with quasi-Newton algorithms that require full Hessian matrix computations, we present a memory-efficient alternative. Our approach intelligently downsamples gradient information, significantly reducing computational requirements while maintaining performance. The approach is validated through experiments on the sparse-view CT problem, involving various datasets and scanning protocols, and is compared with post-processing and deep unrolling state-of-the-art approaches. Our method outperforms existing approaches and achieves state-of-the-art performance in terms of SSIM and PSNR, all while reducing the number of unrolling iterations required., Comment: Accepted at CVPR 2024. Project page: https://towzeur.github.io/QN-Mixer/

Published
2024

3. An analytical reconstruction formula with efficient implementation for a modality of Compton Scattering Tomography with translational geometry

Author

Tarpau, Cécilia, Cebeiro, Javier, Rollet, Geneviève, Nguyen, Mai K., and Dumas, Laurent

Subjects
Mathematics - Numerical Analysis, Mathematical Physics
Abstract

In this paper, we address an alternative formulation for the exact inverse formula of the Radon transform on circle arcs arising in a modality of Compton Scattering Tomography in translational geometry proposed by Webber and Miller (Inverse Problems (36)2, 025007, 2020). The original study proposes a first method of reconstruction, using the theory of Volterra integral equations. The numerical realization of such a type of inverse formula may exhibit some difficulties, mainly due to stability issues. Here, we provide a suitable formulation for exact inversion that can be straightforwardly implemented in the Fourier domain. Simulations are carried out to illustrate the efficiency of the proposed reconstruction algorithm., Comment: 13 pages, 6 figures

Published
2021

4. Mouse midbrain dopaminergic neurons survive loss of the PD-associated mitochondrial protein CHCHD2.

Author

Nguyen, Mai K, McAvoy, Kevin, Liao, Szu-Chi, Doric, Zak, Lo, Iris, Li, Huihui, Manfredi, Giovanni, and Nakamura, Ken

Subjects
Aging, Brain Disorders, Neurosciences, Neurodegenerative, Parkinson's Disease, Aetiology, 2.1 Biological and endogenous factors, Neurological, Animals, DNA-Binding Proteins, Dopaminergic Neurons, Female, Male, Mice, Mitochondrial Proteins, Substantia Nigra, Transcription Factors, Biological Sciences, Medical and Health Sciences, Genetics & Heredity
Abstract

Mutations in the mitochondrial protein CHCHD2 cause autosomal dominant Parkinson's disease characterized by the preferential loss of substantia nigra dopamine (DA) neurons. Therefore, understanding the function of CHCHD2 in neurons may provide vital insights into how mitochondrial dysfunction contributes to neurodegeneration in PD. To investigate the normal requirement and function of CHCHD2 in neurons, we first examined CHCHD2 levels and showed that DA neurons have higher CHCHD2 levels than other neuron types, both in vivo and in co-culture. We then generated mice with either a targeted deletion of CHCHD2 in DA neurons or a deletion in the brain or total body. All three models were viable, and loss of CHCHD2 in the brain did not cause degeneration of DA neurons. Mice lacking CHCHD2 in DA neurons did display sex-specific changes to locomotor activity, but we did not observe differences in assays of muscle strength, exercise endurance or motor coordination. Furthermore, mitochondria derived from mice lacking CHCHD2 did not display abnormalities in OXPHOS function. Lastly, resilience to CHCHD2 deletion could not be explained by functional complementation by its paralog CHCHD10, as deletion of both CHCHD10 and CHCHD2 did not cause degeneration of DA neurons in the midbrain. These findings support the hypothesis that pathogenic CHCHD2 mutations cause PD through a toxic gain-of-function, rather than loss-of-function mechanism.

Published
2022

5. On the design of a CST system and its extension to a bi-imaging modality

Author

Tarpau, Cécilia, Cebeiro, Javier, Nguyen, Mai K., Rollet, Gevneviève, and Dumas, Laurent

Subjects
Physics - Medical Physics
Abstract

In material testing applications, Computed Tomography is a well established imaging technique that allows the recovery of the attenuation map of an object. Conventional modalities exploit only primary radiation and although in the energy ranges used in industrial applications Compton scatter radiation is significant, it is removed from the measured data. On the contrary, Compton Scattering Tomography not only accounts for the Compton effect but also uses it to image material electronic density. Despite its promising applications, some aspects of Compton scattering tomography have not been studied so far and, since they are necessary for the design of a operational system, they need to be addressed. In this paper we analyze the effect of some physical influences regarding real detectors for the Circular Compton Scattering tomography, a system recently introduced by the authors. This is accomplished through the formulation of a new weighted Radon transform. In addition, we propose to adapt the acquired data with pre-processing steps so that they are suitable for reconstruction with a filtered back-projection type reconstruction algorithm, and thus, properly deal with missing data of real measurements. Finally, we introduce a bi-imaging configuration that allows recovering simultaneously the electronic density map of the object as well as its attenuation map., Comment: 13 pages, 20 figures

Published
2020

6. Longitudinal tracking of neuronal mitochondria delineates PINK1/Parkin-dependent mechanisms of mitochondrial recycling and degradation

Author

Li, Huihui, Doric, Zak, Berthet, Amandine, Jorgens, Danielle M, Nguyen, Mai K, Hsieh, Ivy, Margulis, Julia, Fang, Rebecca, Debnath, Jayanta, Sesaki, Hiromi, Finkbeiner, Steve, Huang, Eric, and Nakamura, Ken

Subjects
Biochemistry and Cell Biology, Biological Sciences, Neurosciences, Neurodegenerative, Parkinson's Disease, Brain Disorders, Aetiology, 1.1 Normal biological development and functioning, 2.1 Biological and endogenous factors, Underpinning research, Neurological
Abstract

Altered mitochondrial quality control and dynamics may contribute to neurodegenerative diseases, including Parkinson's disease, but we understand little about these processes in neurons. We combined time-lapse microscopy and correlative light and electron microscopy to track individual mitochondria in neurons lacking the fission-promoting protein dynamin-related protein 1 (Drp1) and delineate the kinetics of PINK1-dependent pathways of mitochondrial quality control. Depolarized mitochondria recruit Parkin to the outer mitochondrial membrane, triggering autophagosome formation, rapid lysosomal fusion, and Parkin redistribution. Unexpectedly, these mitolysosomes are dynamic and persist for hours. Some are engulfed by healthy mitochondria, and others are deacidified before bursting. In other cases, Parkin is directly recruited to the matrix of polarized mitochondria. Loss of PINK1 blocks Parkin recruitment, causes LC3 accumulation within mitochondria, and exacerbates Drp1KO toxicity to dopamine neurons. These results define a distinct neuronal mitochondrial life cycle, revealing potential mechanisms of mitochondrial recycling and signaling relevant to neurodegeneration.

Published
2021

7. Defining the ATPome reveals cross-optimization of metabolic pathways.

Author

Bennett, Neal K, Nguyen, Mai K, Darch, Maxwell A, Nakaoka, Hiroki J, Cousineau, Derek, Ten Hoeve, Johanna, Graeber, Thomas G, Schuelke, Markus, Maltepe, Emin, Kampmann, Martin, Mendelsohn, Bryce A, Nakamura, Jean L, and Nakamura, Ken

Subjects
Cell Line, K562 Cells, Mitochondria, Fibroblasts, Humans, Hexokinase, Glucose, Adenosine Triphosphate, Gene Expression Regulation, Energy Metabolism, Glycolysis, Point Mutation, Female, Pentose Phosphate Pathway, Metabolic Networks and Pathways, Metabolomics, Gene Knockdown Techniques, CRISPR-Cas Systems
Abstract

Disrupted energy metabolism drives cell dysfunction and disease, but approaches to increase or preserve ATP are lacking. To generate a comprehensive metabolic map of genes and pathways that regulate cellular ATP-the ATPome-we conducted a genome-wide CRISPR interference/activation screen integrated with an ATP biosensor. We show that ATP level is modulated by distinct mechanisms that promote energy production or inhibit consumption. In our system HK2 is the greatest ATP consumer, indicating energy failure may not be a general deficiency in producing ATP, but rather failure to recoup the ATP cost of glycolysis and diversion of glucose metabolites to the pentose phosphate pathway. We identify systems-level reciprocal inhibition between the HIF1 pathway and mitochondria; glycolysis-promoting enzymes inhibit respiration even when there is no glycolytic ATP production, and vice versa. Consequently, suppressing alternative metabolism modes paradoxically increases energy levels under substrate restriction. This work reveals mechanisms of metabolic control, and identifies therapeutic targets to correct energy failure.

Published
2020

8. A high-throughput screen of real-time ATP levels in individual cells reveals mechanisms of energy failure.

Author

Mendelsohn, Bryce A, Bennett, Neal K, Darch, Maxwell A, Yu, Katharine, Nguyen, Mai K, Pucciarelli, Daniela, Nelson, Maxine, Horlbeck, Max A, Gilbert, Luke A, Hyun, William, Kampmann, Martin, Nakamura, Jean L, and Nakamura, Ken

Subjects
Mitochondria, Humans, Ubiquinone, Mitochondrial Proteins, Adenosine Triphosphate, Energy Metabolism, High-Throughput Screening Assays, Single-Cell Analysis, Clustered Regularly Interspaced Short Palindromic Repeats, Biological Sciences, Agricultural and Veterinary Sciences, Medical and Health Sciences, Developmental Biology
Abstract

Insufficient or dysregulated energy metabolism may underlie diverse inherited and degenerative diseases, cancer, and even aging itself. ATP is the central energy carrier in cells, but critical pathways for regulating ATP levels are not systematically understood. We combined a pooled clustered regularly interspaced short palindromic repeats interference (CRISPRi) library enriched for mitochondrial genes, a fluorescent biosensor, and fluorescence-activated cell sorting (FACS) in a high-throughput genetic screen to assay ATP concentrations in live human cells. We identified genes not known to be involved in energy metabolism. Most mitochondrial ribosomal proteins are essential in maintaining ATP levels under respiratory conditions, and impaired respiration predicts poor growth. We also identified genes for which coenzyme Q10 (CoQ10) supplementation rescued ATP deficits caused by knockdown. These included CoQ10 biosynthetic genes associated with human disease and a subset of genes not linked to CoQ10 biosynthesis, indicating that increasing CoQ10 can preserve ATP in specific genetic contexts. This screening paradigm reveals mechanisms of metabolic control and genetic defects responsive to energy-based therapies.

Published
2018

9. Anzu and the Realm of Darkness

Author

Nguyen, Mai K.

Subjects
Bon Festival, Publishing industry
Abstract

MIDDLE GRADE Anzu is used to classmates making fun of her name, food and culture. In a new town, she's prepared for the teasing to continue. When she asks for [...]

Published
2024

10. Loss of α-Synuclein Does Not Affect Mitochondrial Bioenergetics in Rodent Neurons

Author

Pathak, Divya, Berthet, Amandine, Bendor, Jacob T, Yu, Katharine, Sellnow, Rhyomi C, Orr, Adam L, Nguyen, Mai K, Edwards, Robert H, Manfredsson, Fredric P, and Nakamura, Ken

Subjects
Biochemistry and Cell Biology, Biomedical and Clinical Sciences, Biological Sciences, Parkinson's Disease, Stem Cell Research, Neurosciences, Neurodegenerative, Brain Disorders, 2.1 Biological and endogenous factors, Aetiology, Neurological, Animals, Dopamine, Hippocampus, Mice, Knockout, Mitochondria, Neurons, Parkinson Disease, Synapses, alpha-Synuclein, bioenergetics, Neurodegeneration, Synuclein, Parkinson’s Disease
Abstract

Increased α-synuclein (αsyn) and mitochondrial dysfunction play central roles in the pathogenesis of Parkinson's disease (PD), and lowering αsyn is under intensive investigation as a therapeutic strategy for PD. Increased αsyn levels disrupt mitochondria and impair respiration, while reduced αsyn protects against mitochondrial toxins, suggesting that interactions between αsyn and mitochondria influences the pathologic and physiologic functions of αsyn. However, we do not know if αsyn affects normal mitochondrial function or if lowering αsyn levels impacts bioenergetic function, especially at the nerve terminal where αsyn is enriched. To determine if αsyn is required for normal mitochondrial function in neurons, we comprehensively evaluated how lowering αsyn affects mitochondrial function. We found that αsyn knockout (KO) does not affect the respiration of cultured hippocampal neurons or cortical and dopaminergic synaptosomes, and that neither loss of αsyn nor all three (α, β and γ) syn isoforms decreased mitochondria-derived ATP levels at the synapse. Similarly, neither αsyn KO nor knockdown altered the capacity of synaptic mitochondria to meet the energy requirements of synaptic vesicle cycling or influenced the localization of mitochondria to dopamine (DA) synapses in vivo. Finally, αsyn KO did not affect overall energy metabolism in mice assessed with a Comprehensive Lab Animal Monitoring System. These studies suggest either that αsyn has little or no significant physiological effect on mitochondrial bioenergetic function, or that any such functions are fully compensated for when lost. These results implicate that αsyn levels can be reduced in neurons without impairing (or improving) mitochondrial bioenergetics or distribution.

Published
2017

11. Oblique Line Scan Illumination Enables Expansive, Accurate and Sensitive Single Protein Measurements in Solution and in Living Cells

Author

Driouchi, Amine, primary, Bretan, Mason, additional, Davis, Brynmor J., additional, Heckert, Alec, additional, Seeger, Markus, additional, Bradley Silva, Maité, additional, Forrest, William SR., additional, Hsiung, Jessica, additional, Tan, Jiongyi, additional, Yang, Hongli, additional, McSwiggen, David T., additional, Song, Linda, additional, Sule, Askhay, additional, Abaie, Behnam, additional, Conroy, Brianna, additional, Elliott, Liam A., additional, Gonzalez, Eric, additional, Ilkov, Fedor, additional, Isaacs, Joshua, additional, Labaria, George, additional, Lagana, Michelle, additional, Larsen, Delaine D., additional, Margolin, Brian, additional, Nguyen, Mai K., additional, Rine, Jeremy, additional, Tang, Yangzhong, additional, Vana, Martin, additional, Wilkey, Andrew, additional, Zhang, Zhengjian, additional, Basham, Stephen, additional, Ho, Jaclyn J., additional, Johnson, Stephanie, additional, Klammer, Aaron A., additional, Lin, Kevin, additional, Darzacq, Xavier, additional, Betzig, Eric, additional, Berman, Russell T., additional, and Anderson, Daniel J., additional

Published
2023
Full Text
View/download PDF

12. Fingerprint Classification Using Conic Radon Transform and Convolutional Neural Networks

Author

El Hamdi, Dhekra, Elouedi, Ines, Fathallah, Abir, Nguyen, Mai K., Hamouda, Atef, Hutchison, David, Editorial Board Member, Kanade, Takeo, Editorial Board Member, Kittler, Josef, Editorial Board Member, Kleinberg, Jon M., Editorial Board Member, Mattern, Friedemann, Editorial Board Member, Mitchell, John C., Editorial Board Member, Naor, Moni, Editorial Board Member, Pandu Rangan, C., Editorial Board Member, Terzopoulos, Demetri, Editorial Board Member, Tygar, Doug, Editorial Board Member, Weikum, Gerhard, Series Editor, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Blanc-Talon, Jacques, editor, Helbert, David, editor, Philips, Wilfried, editor, Popescu, Dan, editor, and Scheunders, Paul, editor

Published
2018
Full Text
View/download PDF

15. Tomographic reconstruction from sparse-view and limited-angle data using a generative adversarial network

Author

Ayad, Ishak, Tarpau, Cécilia, Cebeiro, Javier, Nguyen, Mai K., and Ayad, Ishak

Subjects
computed tomography (CT), generative adversarial networks (GAN), image reconstruction, inverse problem, hybrid representations, [MATH] Mathematics [math], [INFO] Computer Science [cs], [PHYS] Physics [physics]
Abstract

Limited-angle and sparse-view computed tomography have been widely used to shorten the acquisition time in medical imaging and to offer the possibility of scanning large objects. However, this is a severely ill-posed inverse problem due to missing data. In these scenarios, the well-known filtered back-projection reconstruction technique exhibits severe artifacts and degradation. Recently, deep learning methods have demonstrated impressive performance in computer vision (denoising, classification, etc.) but it frequently fails to solve both limited-angle and sparse-view reconstruction. Inspired by the high performance of GAN-based image-to-image translation methods, we investigate a patchGAN as a solution to the reconstruction problem mapping data (Radon space) into the image domain. The generator is made of a V-net where the reconstruction in the sense of a least-squares minimization is carried out at different scales in the encoder path and linked with the decoder path by skip connections. The discriminator uses both information from the image and projection data domains. The proposed method gives promising reconstruction results from data acquired with a limited angular range covering only 110 degrees (instead of 180 degrees), as well as for sparse-view data with 10 degrees of sampling step. Moreover, different reconstruction results show that the method is able to reconstruct images from sparse and limited angular range data at the same time.

Published
2022
Full Text
View/download PDF

16. Three-Dimensional Object Reconstruction from Compton Scattered Gamma-Ray Data

Author

Nguyen, Mai K., Truong, T. T., Delarbre, J. L., Kitanine, N., Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Sonka, Milan, editor, Kakadiaris, Ioannis A., editor, and Kybic, Jan, editor

Published
2004
Full Text
View/download PDF

18. An analytical reconstruction formula with efficient implementation for a modality of Compton Scattering Tomography with translational geometry

Author

Tarpau, C��cilia, Cebeiro, Javier, Rollet, Genevi��ve, Nguyen, Mai K., and Dumas, Laurent

Subjects
FOS: Mathematics, FOS: Physical sciences, Numerical Analysis (math.NA), Mathematical Physics (math-ph), Mathematics - Numerical Analysis, Mathematical Physics
Abstract

In this paper, we address an alternative formulation for the exact inverse formula of the Radon transform on circle arcs arising in a modality of Compton Scattering Tomography in translational geometry proposed by Webber and Miller (Inverse Problems (36)2, 025007, 2020). The original study proposes a first method of reconstruction, using the theory of Volterra integral equations. The numerical realization of such a type of inverse formula may exhibit some difficulties, mainly due to stability issues. Here, we provide a suitable formulation for exact inversion that can be straightforwardly implemented in the Fourier domain. Simulations are carried out to illustrate the efficiency of the proposed reconstruction algorithm., 13 pages, 6 figures

Published
2021

20. On a novel approach to Compton scattered emission imaging

Author

Nguyen, Mai K., Truong, Tuong T., Driol, Clemence, and Zaidi, Habib

Subjects
CT imaging -- Research, Scattering (Physics) -- Research, Business, Electronics, Electronics and electrical industries
Abstract

Imaging processes built on the Compton scattering effect are currently under intense investigation. However, despite many innovative contributions, this topic still pose a formidable mathematical and technical challenge. In this work, we argue that, in the framework of single-photon emission imaging, collecting Compton scattered radiation from an emitting object, allows to image the radiotracer distribution in vivo. Data is acquired by a stationary collimated gamma camera under the form of compounded conical projections of the activity density function. Mathematically, the image formation process is described by the so-called Compounded Conical Radon Transform (CCRT) and three-dimensional object reconstruction is based on an inversion formula of the CCRT. We perform numerical simulations to show the feasibility of this new imaging modality, which offers the remarkable advantage of operating in stationary mode without the need of bulky and cumbersome spatial rotational mechanism of conventional gamma cameras. This is highly attractive for applications in medical imaging, industrial non-destructive evaluation, nuclear waste storage surveillance and homeland security monitoring. Finally, to improve drastically the sensitivity, we introduce a new feature allowing to acquire data without mechanical collimation and support the findings with some preliminary simulation results. Index Terms--Compton imaging, Compton scattering, computed tomography imaging, SPECT, SPECT reconstruction.

Published
2009

21. Deep morphological network-based artifact suppression for limited-angle tomography

Author

Ayad, Ishak, Tarpau, Cécilia, Nguyen, Mai K., Vu, Ngoc-Son, and Ayad, Ishak

Subjects
[INFO.INFO-AI] Computer Science [cs]/Artificial Intelligence [cs.AI], [INFO.INFO-TI] Computer Science [cs]/Image Processing [eess.IV], Mathematical morphology, Image reconstruction, [INFO.INFO-IM] Computer Science [cs]/Medical Imaging, Deep learning, Limited angular projections, Computed tomography, U-Net
Abstract

Computed tomography has been widely used in biomedical and industrial applications. The well-known filtered back-projection algorithm, probably the most used reconstruction technique, fails when the angular range used for data acquisition is not sufficient. As a consequence, reconstructions exhibit artifacts. In order to eliminate these artifacts, we propose in this article a new deep learning approach based on a U-net architecture which includes a morphological operation. This operation of mathematical morphology allows us to capture better some non-linear properties of the object to reconstruct. The proposed method provides good results for angular ranges of 170, 150, 130 and even 110 degrees. To the best of our knowledge, it is the first time a limited-angle artifact suppression method works with 110 projections.

Published
2021

22. On the design of a CST system and its extension to a bi-imaging modality

Author

Tarpau, C��cilia, Cebeiro, Javier, Nguyen, Mai K., Rollet, Gevnevi��ve, and Dumas, Laurent

Subjects
FOS: Physical sciences, Medical Physics (physics.med-ph), Physics - Medical Physics
Abstract

In material testing applications, Computed Tomography is a well established imaging technique that allows the recovery of the attenuation map of an object. Conventional modalities exploit only primary radiation and although in the energy ranges used in industrial applications Compton scatter radiation is significant, it is removed from the measured data. On the contrary, Compton Scattering Tomography not only accounts for the Compton effect but also uses it to image material electronic density. Despite its promising applications, some aspects of Compton scattering tomography have not been studied so far and, since they are necessary for the design of a operational system, they need to be addressed. In this paper we analyze the effect of some physical influences regarding real detectors for the Circular Compton Scattering tomography, a system recently introduced by the authors. This is accomplished through the formulation of a new weighted Radon transform. In addition, we propose to adapt the acquired data with pre-processing steps so that they are suitable for reconstruction with a filtered back-projection type reconstruction algorithm, and thus, properly deal with missing data of real measurements. Finally, we introduce a bi-imaging configuration that allows recovering simultaneously the electronic density map of the object as well as its attenuation map., 13 pages, 20 figures

Published
2020

24. Object classification using Radon transform and Convolutional Neural Networks

Author

El Hamdi, Dhekra, Elouedi, Ines, Fathallah, Abir, Nguyen, Mai K., Hamouda, Atef, Université de Tunis El Manar (UTM), Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), and Nguyen, Mai K.

Subjects
[SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, [INFO.INFO-CV] Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV], [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Convolutional Neural Networks, Object classification, [INFO.INFO-CV]Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV], [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing, Conic Radon Transform
Abstract

International audience; This paper presents a novel approach to perform object classification based on combining the conic Radon transform (CRT) and the convolutional neural networks (CNN). The CRT generalizes the classical Radon transform (RT) to detect conic sections in images. We have build, in this work, a descriptor combining the extracted features by the circular, parabolic and linear RT. The obtained descriptor is then entered as an inputinto the convolutional layers. In order to evaluate the efficiency of this approach, we have carried out experiments on the ETH80 data set. The obtainedresults show the performance of this new approach which joins together extraction of features of different (circular, parabolic and linear) shapes and the convolutional neural networks. Since the use of large database is required for deep learning techniques to get accurate results, we investigate in this work the use of small database on simple CNN models. Our technique achieved competitive classification accuracy and superior computationalcomplexity compared to the state-of-the-art methods.

Published
2018

25. A Toric Radon Transform and its connection with other Radon type transforms

Author

Cebeiro, Javier, Tarpau, Cécilia, Morvidone, Marcela, Rubio, Diana, Nguyen, Mai K., Centro de Matematica Aplicada [San Martín] (CEDEMA), Escuela de Ciencia y Tecnología [San Martín] (ECyT), Universidad Nacional de San Martin (UNSAM)-Universidad Nacional de San Martin (UNSAM), Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), and TARPAU, Cécilia

Subjects
[INFO.INFO-IM] Computer Science [cs]/Medical Imaging, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, ComputingMilieux_MISCELLANEOUS, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience

Published
2019

26. On the invertibility of a new toric Radon trans-form with applications in Compton scatter tomography

Author

Cebeiro, Javier, Morvidone, Marcela, Tarpau, Cécilia, Nguyen, Mai K., Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Centro de Matematica Aplicada [San Martín] (CEDEMA), Escuela de Ciencia y Tecnología [San Martín] (ECyT), Universidad Nacional de San Martin (UNSAM)-Universidad Nacional de San Martin (UNSAM), and TARPAU, Cécilia

Subjects
[INFO.INFO-IM] Computer Science [cs]/Medical Imaging, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, ComputingMilieux_MISCELLANEOUS, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience

Published
2019

27. The development of Radon transforms associated to Compton scatter imaging concepts

Author

Nguyen, Mai K., Truong, T. T., Nguyen, Mai K., Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Laboratoire de Physique Théorique et Modélisation (LPTM - UMR 8089), and CY Cergy Paris Université (CY)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, V-line Radon Transform, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, [MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph], Generalized Radon Transforms, [MATH.MATH-MP] Mathematics [math]/Mathematical Physics [math-ph], [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Tomography, Cone Radon Transform, Compton Scatter Imaging, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience; For more than three decades, the exploitation of Compton scattering has led to significant progress in imaging the inner parts of an optically opaque object. In this imaging process, the Compton scattering angle plays an essential role as it labels the recorded data, suppressing the motion of the scanning camera, as well as generates new geometric manifolds on which radiation measurements are made and thereby introducing new relevant Radon transforms. The present paper is aimed to synthetize the conceptual development of Compton scattering imaging in order to gain a constructive overview and possibly induce a further innovative growth to it. We believe this may lay foundation to new mathematical tools as well as lead to a great diversity of applications.

Published
2018

29. A new bi-imaging NDT system for simultaneous recovery of attenuation and electronic density maps

Author

TARPAU, Cécilia, Cebeiro, Javier, Nguyen, Mai K., TARPAU, Cécilia, Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), CY Cergy Paris Université (CY)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA), Laboratoire de Physique Théorique et Modélisation (LPTM - UMR 8089), Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Laboratoire de Mathématiques de Versailles (LMV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centro de Matematica Aplicada [San Martín] (CEDEMA), Escuela de Ciencia y Tecnología [San Martín] (ECyT), and Universidad Nacional de San Martin (UNSAM)-Universidad Nacional de San Martin (UNSAM)

Subjects
[PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], [PHYS.MPHY] Physics [physics]/Mathematical Physics [math-ph], [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, ComputingMilieux_MISCELLANEOUS, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience

Published
2019

30. Radon transforms on circular arcs and their associated modalities of Compton Scattering Tomography

Author

TARPAU, Cécilia, Cebeiro, Javier, Nguyen, Mai K., TARPAU, Cécilia, Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), CY Cergy Paris Université (CY)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA), Laboratoire de Physique Théorique et Modélisation (LPTM - UMR 8089), Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Laboratoire de Mathématiques de Versailles (LMV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centro de Matematica Aplicada [San Martín] (CEDEMA), Escuela de Ciencia y Tecnología [San Martín] (ECyT), and Universidad Nacional de San Martin (UNSAM)-Universidad Nacional de San Martin (UNSAM)

Subjects
[INFO.INFO-IM]Computer Science [cs]/Medical Imaging, [INFO.INFO-IM] Computer Science [cs]/Medical Imaging, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, ComputingMilieux_MISCELLANEOUS, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience

Published
2019

33. A novel modality of Compton Scattering Tomography, Image formation and Reconstruction

Author

Tarpau, Cécilia, Nguyen, Mai K., Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), and TARPAU, Cécilia

Subjects
[INFO.INFO-IM] Computer Science [cs]/Medical Imaging, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, ComputingMilieux_MISCELLANEOUS, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience

Published
2018

36. Towards a new concept for high sensitivity Compton scatter emission imaging

Author

Nguyen Mai K., Driol Clémence, Truong Tuong T., and Zaidi Habib

Subjects
emission imaging, sensitivity, compton scattering, image formation, image reconstruction, Applied optics. Photonics, TA1501-1820, Optics. Light, QC350-467
Abstract

A new efficient scheme for imaging gamma-emitting objects is advocated in this work. It is elaborated on the recent idea of collecting data, using a detector equipped with a parallel-hole collimator, from Compton scattered photons to reconstruct an object in three-dimensions. This paper examines a working mode without collimation, which should increase its sensitivity and field of view. To simplify the otherwise complex mathematical formulation, we choose to discuss the image formation process in two-dimensions, which can be implemented with a slit collimator. Comparison with the standard collimated case, via the analysis of the shapes of the respective point spread functions (PSF), shows marked improvements and numerical simulation results, obtained using a brain phantom, support the viability and attractiveness of this new imaging modality.

Published
2008
Full Text
View/download PDF

37. The adjoint operator of the Radon transform on rotating V-lines and its role in image reconstruction

Author

Cebeiro, Javier, Morvidone, M., Nguyen, Mai K., Nguyen, Mai K., Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Universidad Nacional de San Martin (UNSAM), Centro de Matematica Aplicada [San Martín] (CEDEMA), Escuela de Ciencia y Tecnología [San Martín] (ECyT), and Universidad Nacional de San Martin (UNSAM)-Universidad Nacional de San Martin (UNSAM)

Subjects
back-projection, [SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, Radon transforms, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Astrophysics::High Energy Astrophysical Phenomena, gamma-ray imaging, Rotating V-line transform, Compton scattering, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience; Integral transformations over conical sets appear as the natural mathematical models in scattered radiation imaging. Compton cameras are emblematic examples of these imaging techniques. The concept of Compton camera originates from the need to improve sensitivity in Single Photon Emission Imaging, which uses hole collimators. It advocates electronic collimation which registers radiation emitted by the radiating object and scattered by a scattering detector placed before an absorption detector. The data consists of three dimensional conical projections of the activity density of a radio-tracer. We consider here a particular two-dimensional Compton camera in which the collected data consists of the set of integrals of the density on rotating V-lines. We present approximate reconstructions obtained both from an adequate back-projection procedure, and from the action of the adjoint operator of this transform. The relation between these operators is also established.

Published
2017

38. V-line and Cone Radon transforms: overview and applications to cultural heritage object imaging

Author

Nguyen, Mai K., Nguyen, Mai K., Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), and Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
V-line Radon transform, [SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, Cone Radon transform, Compton scatter imaging, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, [MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph], [MATH.MATH-MP] Mathematics [math]/Mathematical Physics [math-ph], [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience; We present an overview of the so-called V-line and Cone Radon transforms as they arise in Compton scatter imaging and give a short account of the latest developments on this concept in recent years which are relevant for imaging processes in many fields of applications. After recalling their applications in Compton scatter imaging, we show how the two transforms may be supporting a successful cultural heritage object imaging research.

Published
2017

39. Simulation d'une nouvelle modalité d'imagerie basée sur le rayonnement X diffusé

Author

Guerrero Prado, Patricio, Nguyen, Mai K., Dumas, Laurent, Cohen, Serge, Institut photonique d'analyse non-destructive européen des matériaux anciens (IPANEMA), Muséum national d'Histoire naturelle (MNHN)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC), Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), CY Cergy Paris Université (CY)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA), Laboratoire de Mathématiques de Versailles (LMV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut Elie Cartan de Lorraine et SMAI, Nguyen, Mai K., and Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
Compton scatter tomography, [SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Conical Radon Transform
Abstract

International audience; Patrimonial and ancient material objets having a attened geometry, i.e. having a large ratio between the top or bottom area and its thickness, are nowadays dicult to study with classic radiation tomography methods. A Compton Scatter Tomography (CST) approach is then envisaged.While incoherent (Compton) scattering data is usually considered as noise, it will be treated in this work as the primary phenomenon of the image formation process. In a Compton event, an incident photon of energy E0 is absorbed by a target electron, who re-emits a secondary photon scattered by an angle 'omega' relative to the direction of the original photon. The scattered photon has an energy E'omega' < E0 and it will be the collected information to perform the in-depth reconstruction, without the need of rotating the system. The energy loss is practically encoding the scattering angle information.

Published
2016

40. Biometry based on retinal analysis

Author

Boucherk, Kahina, Zohra, Ameur, Nguyen, Mai K., Laboratoire d’Analyse et de Modélisation des Phénomènes Aléatoires( LAMPA), Université Mouloud Mammeri Tizi Ouzou, Algérie, Laboratoire d'Analyse & Modélisation des Phénomènes Aléatoires [Tizi-Ouzou] (LAMPA), Université Mouloud Mammeri [Tizi Ouzou] (UMMTO), Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), and Nguyen, Mai K.

Subjects
[SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Computer Science::Computer Vision and Pattern Recognition, rétine, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, crossing number, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, seuillage entropique, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing, filtre gaussien, segmentation d’images
Abstract

International audience; The biometrics analysis is among powerful technics used for people recognition. It’s well adapted for high security applications. In this paper, we present a method of vascular retina network segmentation with characteristic points detection used as biometric signature. The method consists of three steps: first, enhancement of images using Gaussian filters network oriented in several directions. Second, binarisation based on entropic thresholding. In the final step, the intersection points characterizing the vascular network are extracted.

Published
2016

43. Backprojection of a conical Radon Transform in Compton scatter tomography

Author

Guerrero, Patricio, Dumas, Laurent, Nguyen, Mai K., Cohen, Serge X., Fondation des Sciences du Patrimoine, LabEx PATRIMA, Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Laboratoire de Mathématiques de Versailles (LMV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut photonique d'analyse non-destructive européen des matériaux anciens (IPANEMA), Muséum national d'Histoire naturelle (MNHN)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC), Guerrero, Patricio, and CY Cergy Paris Université (CY)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)

Subjects
[MATH.MATH-GM]Mathematics [math]/General Mathematics [math.GM], [MATH.MATH-GM] Mathematics [math]/General Mathematics [math.GM], [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, ComputingMilieux_MISCELLANEOUS, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract

National audience

Published
2016

45. In-depth imaging of flat ancient material objects: backprojection reconstruction of a 2D conical Radon Transform

Author

Guerrero, Patricio, Cohen, Serge X., Nguyen, Mai K., Dumas, Laurent, Guerrero, Patricio, Fondation des Sciences du Patrimoine, LabEx PATRIMA, Institut photonique d'analyse non-destructive européen des matériaux anciens (IPANEMA), Muséum national d'Histoire naturelle (MNHN)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC), Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), CY Cergy Paris Université (CY)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA), Laboratoire de Mathématiques de Versailles (LMV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
[MATH.MATH-GM]Mathematics [math]/General Mathematics [math.GM], [MATH.MATH-GM] Mathematics [math]/General Mathematics [math.GM], [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, ComputingMilieux_MISCELLANEOUS, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience

Published
2016

48. Compton scattered radiation imaging and Bimodality

Author

Nguyen, Mai K., Nguyen, Mai K., Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), and Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
[SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2013

49. This title is unavailable for guests, please login to see more information.

Author

Pathak, Divya, Pathak, Divya, Berthet, Amandine, Bendor, Jacob T, Yu, Katharine, Sellnow, Rhyomi C, Orr, Adam L, Nguyen, Mai K, Edwards, Robert H, Manfredsson, Fredric P, Nakamura, Ken, Pathak, Divya, Pathak, Divya, Berthet, Amandine, Bendor, Jacob T, Yu, Katharine, Sellnow, Rhyomi C, Orr, Adam L, Nguyen, Mai K, Edwards, Robert H, Manfredsson, Fredric P, and Nakamura, Ken

Published
2017

50. Une nouvelle modalité de la tomographie Compton pour le contrôle non destructif

Author

Nguyen, Mai K., Rigaud, Gaël, Nguyen, Mai K., ICI, Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), and Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
[SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2011

Catalog

Books, media, physical & digital resources
See catalog results