- Grenoble, France
Francoise PEYRIN
INSA Lyon, Electrcal Eng, Faculty Member
Bone metastases are frequent complications of breast cancer, facilitating the development of anarchic vascularization and induce bone destruction. Therefore, anti-angiogenic drugs (AAD) have been tested as a therapeutic strategy for the... more
Bone metastases are frequent complications of breast cancer, facilitating the development of anarchic vascularization and induce bone destruction. Therefore, anti-angiogenic drugs (AAD) have been tested as a therapeutic strategy for the treatment of breast cancer bone metastasis. However, the kinetics of skeletal vascularization in response to tumor invasion under AAD is still partially understood. Therefore, the aim of this study was to explore the effect of AAD on experimental bone metastasis by analyzing the three-dimensional (3D) bone vasculature during metastatic formation and progression. Seventy-three eight-week-old female mice were treated with AAD (bevacizumab, vatalanib, or a combination of both drugs) or the vehicle (placebo) one day after injection with breast cancer cells. Mice were sacrificed eight or 22 days after tumor cell inoculation (time points T1 and T2, respectively). Synchrotron radiation microcomputed tomography (SR-μCT) was used to image bone and blood vesse...
Research Interests:
Research Interests:
Research Interests:
articleBone microarchitecture is receiving increasing attention in theassessment of the biomechanical properties of bone. While it iswell characterized in normal and pathologic human subjects,few quantitative data are available in human... more
articleBone microarchitecture is receiving increasing attention in theassessment of the biomechanical properties of bone. While it iswell characterized in normal and pathologic human subjects,few quantitative data are available in human fetal development.In this paper, quantitative parameters of bone microarchitecturein developing human bone are reviewed from the literature andsupplemented by new data from the femoral metaphysis of hu-man fetuses. The samples were imaged using synchrotron radi-ation 3D micro-CT and processed using customized analysismethods. This technique provides 3D model independent mor-phometric parameters, anisotropy, connectivity and geometrycharacteristics, as well as information on mineralization.The morphometric parameters obtained on fetal vertebrae andfemurs evidenced a dense trabecular structure as comparedto that of young adults. The histomorphometric and the 3D mi-cro-CT analysis were consistent to show a significant in-crease of trabecular bone volume...
Research Interests:
Research Interests:
In X-ray Computed Tomography, ring artifacts can be caused by imperfect elements in a detector or also by defects or impurities in the scintillator’s crystals. The artifacts appear on Computed Tomographic images as concentric rings... more
In X-ray Computed Tomography, ring artifacts can be caused by imperfect elements in a detector or also by defects or impurities in the scintillator’s crystals. The artifacts appear on Computed Tomographic images as concentric rings superimposed on the images of the structures being scanned. The presence of such artifacts significantly complicates the post processing techniques such as noise reduction, binarization, or segmentation of image information. The efficacy of these techniques depends on the consistency of the method of classification and detection of ring artifacts. In this paper we present a simple, fast and efficient method to detect ring artifacts on Computed Tomographic images in the Polar domain.
Research Interests:
International audienc
Research Interests:
Imaging bone tissue from the organ to the cellular level is a major goal in bone research to understand, diagnose and predict bone fragility associated to bone disease such as osteoporosis. In this presentation, we show that X-ray CT is... more
Imaging bone tissue from the organ to the cellular level is a major goal in bone research to understand, diagnose and predict bone fragility associated to bone disease such as osteoporosis. In this presentation, we show that X-ray CT is particularly well adapted to image bone in 3D up to the nanometer scale. After recalling the principles of 3D CT, we describe advances in bone CT imaging and the needs in associated inverse problems. Clinical X-ray CT is daily used to image skeletal tissue at the organ scale with a spatial resolution of about 0.5mm. However such systems do not permit to image bone micro-architecture made of a complex network of thin trabeculae (thickness about 150 µm). Imaging trabecular bone has been a driving application in the development of X-ray micro-Computerized Tomography (CT) ex-vivo. New High Resolution peripheral Quantitative CT (HR pQCT) systems provide images at voxel size around 100 µm, permitting the investigation of bone micro-structure in vivo [1]. S...
Research Interests:
Research Interests:
Recently, increasing attention has been given to the study of osteocytes, the cells that are thought to play an important role in bone remodeling and in the mechanisms of bone fragility. The interconnected osteocyte system is deeply... more
Recently, increasing attention has been given to the study of osteocytes, the cells that are thought to play an important role in bone remodeling and in the mechanisms of bone fragility. The interconnected osteocyte system is deeply embedded inside the mineralized bone matrix and lies within a closely fitted porosity known as the lacuno-canalicular network. However, quantitative data on human samples remain scarce, mostly measured in 2D, and there are gaps to be filled in terms of spatial resolution. In this work, we present data on femoral samples from female donors imaged with isotropic 3D spatial resolution by magnified X-ray phase nano computerized-tomography. We report quantitative results on the 3D structure of canaliculi in human femoral bone imaged with a voxel size of 30 nm. We found that the lacuno-canalicular porosity occupies on average 1.45% of the total tissue volume, the ratio of the canalicular versus lacunar porosity is about 37.7%, and the primary number of canalic...
Research Interests:
Research Interests:
... They showed that qualitative discrimination was possible between HR-SA-ECG recordings from patients with and without VT. 394 Page 3. ... R Kronland-Martinet, J. Morlet, A. Grossmann, "Analysis of sound patterns through... more
... They showed that qualitative discrimination was possible between HR-SA-ECG recordings from patients with and without VT. 394 Page 3. ... R Kronland-Martinet, J. Morlet, A. Grossmann, "Analysis of sound patterns through wavelet transforms ", International Journal of ...
Research Interests:
Research Interests:
Research Interests: Physics, Materials Science, Fluorescence Microscopy, Image Analysis, Histology, and 15 moreMedicine, Multidisciplinary, Imaging Techniques, Humans, Female, Quality Factor, Male, Bone Density, PLoS one, Aged, Reproducibility of Results, Sensitivity and Specificity, Bone Strength, Bone mass, and Femoral Fractures
We present a new prior for phase retrieval from X-ray Fresnel diffraction patterns. Fresnel diffraction patterns are achieved by letting a highly coherent X-ray beam propagate in free space after interaction with an object. Previously,... more
We present a new prior for phase retrieval from X-ray Fresnel diffraction patterns. Fresnel diffraction patterns are achieved by letting a highly coherent X-ray beam propagate in free space after interaction with an object. Previously, either homogeneous or multi-material object assumptions have been used. The advantage of the homogeneous object assumption is that the prior can be introduced in the Radon domain. Heterogeneous object priors, on the other hand, have to be applied in the object domain. Here, we let the relationship between attenuation and refractive index vary as a function of the measured attenuation index. The method is evaluated using images acquired at beamline ID19 (ESRF, Grenoble, France) of a phantom where the prior is calculated by linear interpolation and of a healing bone obtained from a rat osteotomy model. It is shown that the ratio between attenuation and refractive index in bone for different levels of mineralization follows a power law. Reconstruction wa...
Research Interests:
Research Interests:
Research Interests: Engineering, Materials Science, Biomedical Engineering, Computed Tomography, Medicine, and 15 moreBiological Sciences, Humans, Cancellous bone, Bone, Compressive Strength, Female, Male, Mechanical Testing, Aged, Calcaneus, Fractal Dimension, Compression test, Mechanical Property, Mechanical strength, and Medical and Health Sciences
Research Interests:
Human bone is known to adapt to its mechanical environment in a living body. Both its architecture and microstructure may differ between weight-bearing and non-weight-bearing bones. The aim of the current study was to analyze in three... more
Human bone is known to adapt to its mechanical environment in a living body. Both its architecture and microstructure may differ between weight-bearing and non-weight-bearing bones. The aim of the current study was to analyze in three dimensions, the morphology of the multi-scale porosities on human cortical bone at different locations. Eight paired femoral diaphyses, femoral necks, and radial diaphyses were imaged using Synchrotron Radiation µCT with a 0.7 µm isotropic voxel size. The spatial resolution facilitates the investigation of the multiscale porosities of cortical bone, from the osteonal canals system down to the osteocyte lacunar system. Our results showed significant differences in the microstructural properties, regarding both osteonal canals and osteocytes lacunae, between the different anatomical locations. The radius presents significantly lower osteonal canal volume fraction and smaller osteonal canals than the femoral diaphysis or neck. Osteocytes lacunae observed ...
Research Interests:
Research Interests:
In this work, we address the problem of the reconstruction of binary images from a small number of noisy tomographic projections. Recently, a new stochastic level-set approach was investigated to refine the reconstruction. The main... more
In this work, we address the problem of the reconstruction of binary images from a small number of noisy tomographic projections. Recently, a new stochastic level-set approach was investigated to refine the reconstruction. The main limitation of this method is that it is only changing the boundaries of the reconstructed regions. In this work, we study a new stochastic approach based on Total Variation (TV) regularization with box constraints. The main advantage of this method is that random shape and boundaries variations can be included in a new way and that topology changes can be also added. The methods are tested on two complex bone micro-CT cross-section images for different noise levels and number of projections. While for the higher noise levels, the best reconstructions are obtained with a stochastic diffusion based on the Total Variation regularization, large decreases of the reconstruction errors are obtained when shape and topology noises are used simultaneously.
Research Interests:
ABSTRACT
Research Interests:
Human cortical bone fracture processes depend on the internal porosity network down to the lacunar length scale. Recent results show that at the collagen scale, the maturation of collagen cross-links may have a negative influence on bone... more
Human cortical bone fracture processes depend on the internal porosity network down to the lacunar length scale. Recent results show that at the collagen scale, the maturation of collagen cross-links may have a negative influence on bone mechanical behavior. While the effect of pentosidine on human cortical bone toughness has been studied, the influence of mature and immature enzymatic cross-links has only been studied in relation to strength and work of fracture. Moreover, these relationships have not been studied on different paired anatomical locations. Thus, the aim of the current study was to assess the relationships between both enzymatic and non-enzymatic collagen cross-links and human cortical bone toughness, on four human paired anatomical locations. Single Edge Notched Bending toughness tests were performed for two loading conditions: a quasi-static standard condition, and a condition representative of a fall. These tests were done with 32 paired femoral diaphyses, femoral...
Research Interests:
Resonant ultrasound spectroscopy (RUS) is the state-of-the-art method used to investigate the elastic properties of anisotropic solids. Recently, RUS was applied to measure human cortical bone, an anisotropic material with low Q-factor... more
Resonant ultrasound spectroscopy (RUS) is the state-of-the-art method used to investigate the elastic properties of anisotropic solids. Recently, RUS was applied to measure human cortical bone, an anisotropic material with low Q-factor (20), which is challenging due to the difficulty in retrieving resonant frequencies. Determining the precision of the estimated stiffness constants is not straightforward because RUS is an indirect method involving minimizing the distance between measured and calculated resonant frequencies using a model. This work was motivated by the need to quantify the errors on stiffness constants due to different error sources in RUS, including uncertainties on the resonant frequencies and specimen dimensions and imperfect rectangular parallelepiped (RP) specimen geometry. The errors were first investigated using Monte Carlo simulations with typical uncertainty values of experimentally measured resonant frequencies and dimensions assuming a perfect RP geometry. ...
Research Interests:
Research Interests: Distributed Computing, Quantum Computing, Image Processing, Signal Processing, Quantum Mechanics, and 12 moreDigital Signal Processing, Time Frequency Analysis, Interpolation, Time Domain, Wigner Ville Distribution, Frequency Response, Fourier Transforms, Frequency Domain, Application Software, Sampling Frequency, Distribution Function, and Discrete time
Micro-tomographic imaging of bone micro-architecture is increasingly used on wild and transgenic mice to follow effects of diseases or therapeutics. Synchrotron radiation micro-tomography (SR micro-CT) provides quantitative images at very... more
Micro-tomographic imaging of bone micro-architecture is increasingly used on wild and transgenic mice to follow effects of diseases or therapeutics. Synchrotron radiation micro-tomography (SR micro-CT) provides quantitative images at very high spatial resolution but has mainly been used in vitro. The aim of this work was to show the feasibility of SR micro-CT for assessing bone mineral density and micro-architecture
Research Interests:
ABSTRACT In this work, we use stochastic diffusion equation with a singular diffusivity and a gradient-dependent noise to improve the reconstruction of binary tomography cross-sections obtained from a small number of projections. A first... more
ABSTRACT In this work, we use stochastic diffusion equation with a singular diffusivity and a gradient-dependent noise to improve the reconstruction of binary tomography cross-sections obtained from a small number of projections. A first reconstruction image is obtained with the Total Variation regularization method. The reconstruction is then refined with this stochastic approach. The method is applied to a noisy bone cross-section with 10 projection angles.
Research Interests:
A solution to the problem of undesired cross-terms in the Wigner distribution (WD) of two-dimensional real signals is presented. The solution is to introduce the notion of two-dimensional analytic signal in the WD. The relation between... more
A solution to the problem of undesired cross-terms in the Wigner distribution (WD) of two-dimensional real signals is presented. The solution is to introduce the notion of two-dimensional analytic signal in the WD. The relation between WDs of the two-dimensional real signal and those of its associated two-dimensional analytical signal is discussed and illustrated by an example
Research Interests:
Bone fracture is a major health issue worldwide and consequently there have been extensive investigations into the fracture behavior of human cortical bone. However, the fracture properties of human cortical bone under fall-like loading... more
Bone fracture is a major health issue worldwide and consequently there have been extensive investigations into the fracture behavior of human cortical bone. However, the fracture properties of human cortical bone under fall-like loading conditions remains poorly documented. Further, most published research has been performed on femoral diaphyseal bone, whereas it is known that the femoral neck and the radius are the most vulnerable sites to fracture. Hence, the aim of this study is to provide information on human cortical bone fracture behavior by comparing different anatomical sites including the radius and the femoral neck acquired from 32 elderly subjects (50 - 98 y.o.). In order to investigate the intrinsic fracture behavior of human cortical bone, toughness experiments were performed at two different strain rates: standard quasi-static conditions, and a higher strain rate representative of a fall from a standing position. The tests were performed on paired femoral neck, femoral...
Research Interests:
The rapid and effective bone regeneration of large non-healing defects remains challenging. Bioactive proteins, such as bone morphogenetic protein (BMP)-2, are proved their osteoinductivity, but their clinical use is currently limited to... more
The rapid and effective bone regeneration of large non-healing defects remains challenging. Bioactive proteins, such as bone morphogenetic protein (BMP)-2, are proved their osteoinductivity, but their clinical use is currently limited to collagen as biomaterial. Being able to deliver BMP-2 from any other biomaterial would broaden its clinical use. This work presents a novel means for repairing a critical size volumetric bone femoral defect in the rat by combining a osteoinductive surface coating (2D) to a polymeric scaffold (3D hollow tube) made of commercially-available PLGA. Using a polyelectrolyte film as BMP-2 carrier, we tune the amount of BMP-2 loaded in and released from the polyelectrolyte film coating over a large extent by controlling the film crosslinking level and initial concentration of BMP-2 in solution. Using microcomputed tomography and quantitative analysis of the regenerated bone growth kinetics, we show that the amount of newly formed bone and kinetics can be modulated: an effective and fast repair was obtained in 1-2 weeks in the best conditions, including complete defect bridging, formation of vascularized and mineralized bone tissue. Histological staining and high-resolution computed tomography revealed the presence of bone regeneration inside and around the tube with spatially distinct organization for trabecular-like and cortical bones. The amount of cortical bone and its thickness increased with the BMP-2 dose. In view of the recent developments in additive manufacturing techniques, this surface-coating technology may be applied in combination with various types of polymeric or metallic scaffolds to offer new perspectives of bone regeneration in personalized medicine.
Research Interests:
... Thus, having a model of the bone microarchitecture could be useful to perform tomographic reconstruction from a limited number of projections and a low X-ray dose. (a) (b) Fig. ... [5] XavierDESCOMBES, Champs markoviens en analyse... more
... Thus, having a model of the bone microarchitecture could be useful to perform tomographic reconstruction from a limited number of projections and a low X-ray dose. (a) (b) Fig. ... [5] XavierDESCOMBES, Champs markoviens en analyse d'images, Ph.D. thesis, ENST, 1993. ...
Research Interests:
Research Interests:
ABSTRACT
ABSTRACT The preferred assessment of bone biomechanical competence in vitro is by direct mechanical testing and in vivo by X-ray absorptiometry techniques. For more than 30 years investigators have been developing alternative techniques,... more
ABSTRACT The preferred assessment of bone biomechanical competence in vitro is by direct mechanical testing and in vivo by X-ray absorptiometry techniques. For more than 30 years investigators have been developing alternative techniques, by ultrasonic methods, aimed at providing (i) the elastic properties in vitro without the complications related the destructive character of mechanical testing and (ii) the evaluation of the fracture risk in vivo, taking benefit of the propagation of elastic wave which are inherently affected by both material and structural bone properties. The in vitro strategy includes the use of multiscale ultrasonic assessment for the combined evaluation of both the material (or intrinsic) and the structural elastic properties in various axes of symmetry. The in vivo approach involves the use of the different propagation modes (bulk wave, guided wave, surface wave) permitted by the ultrasonic approach. We will review the in vitro and clinical data on each ultrasonic approach and discuss potential areas of development in the field of quantitative bone assessment bone.
Research Interests:
Research Interests:
The present paper is devoted to a comparison between time- resolved fluorescence diffuse optical tomography and continuous wave fluorescence diffuse optical tomography. Both of these techniques aim at reconstructing 3D biodistribution of... more
The present paper is devoted to a comparison between time- resolved fluorescence diffuse optical tomography and continuous wave fluorescence diffuse optical tomography. Both of these techniques aim at reconstructing 3D biodistribution of fluorescent markers embedded in biological tissues. The study is restricted in the time domain to the exploitation of the first three temporal moments of measurements. The temporal benefits in terms of reconstruction have been shown to depend strongly on the optical parameters of the medium investigated as well as the fluorescence lifetime.
Research Interests:
Research Interests:
Research Interests:
ABSTRACT Practical applications of the discrete version of the Wigner-Ville transform (WVT) to the real-time digital processing of one-dimensional signals and two-dimensional and three-dimensional images are discussed. It is shown how... more
ABSTRACT Practical applications of the discrete version of the Wigner-Ville transform (WVT) to the real-time digital processing of one-dimensional signals and two-dimensional and three-dimensional images are discussed. It is shown how many of the WVT properties can be simply deduced from those of the Fourier transform, and the characteristics of the present method are compared with those of the spectrogram method. In its discrete formulation, and due to the introduction of a sliding window, this transform is found to be well suited for quasi-real-time applications and to provide fast digital processing. A joint representation method in a space-frequency domain is considered to extend the application of the WVT to multidimensional signals and images.