Jean-Luc Gennisson

Jean-Luc Gennisson
French National Centre for Scientific Research | CNRS · Institut des sciences de l'ingénierie et des systèmes (INSIS)

Ph.D.

About

253
Publications
47,795
Reads
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10,650
Citations
Additional affiliations
October 2019 - present
French National Centre for Scientific Research
Position
  • Directeur de recherche 2ième classe
June 2017 - present
French National Centre for Scientific Research
Position
  • Charge de recherche 1ere classe
October 2005 - June 2017
École Supérieure de Physique et de Chimie Industrielles
Position
  • Charge de recherche 1ere classe

Publications

Publications (253)
Article
Recent developments in the field of elastography aim at developing the quantification of new mechanical properties of tissues, that are complementary to the shear modulus, which is characteristic of the linear elastic properties of a quasi-incompressible medium. In this context, measurement of the elastic nonlinearity of tissues was recently propos...
Article
Background The relationship between the diaphragm thickening fraction and the transdiaphragmatic pressure, the reference method to evaluate the diaphragm function, has not been clearly established. This study investigated the global and intraindividual relationship between the thickening fraction of the diaphragm and the transdiaphragmatic pressure...
Article
No PDF available ABSTRACT In vivo muscle biomechanical properties are classically deduced from inverse dynamics or measures of joint torque performed using ergometers. However, this provide information about the combined behavior of several structures. Thus, it is complicated to isolate the behavior of an individual muscle. Ultrasound elastography...
Article
Using shear wave elastography, we measure the changes in the wave speed with the stress produced by a striated muscle during isometric voluntary contraction. To isolate the behaviour of an individual muscle from complementary or antagonistic actions of adjacent muscles, we select the \textit{flexor digiti minimi} muscle, whose sole function is to e...
Chapter
Non-invasive characterization of renal parenchymal diseases is a challenge for nephrologists. Imaging could play a major role in the future for that purpose but our techniques still require more validation in terms of diagnosis or prognosis. To now, imaging of the kidney has been mainly based on morphological evaluation of the parenchyma and intrar...
Article
This study presents a novel ultrasound method for exploring the mechanical deformability of artificial tongue models (ATMs) topped with agar and/or gelatin food gels during uniaxial compression. The ATMs were made from polyvinyl alcohol and displayed different levels of rigidity and surface roughness. We quantified deformation of the ATM-food syste...
Article
Full-text available
Malignant tumors have abnormal biomechanical characteristics, including high viscoelasticity, solid stress, and interstitial fluid pressure. Magnetic resonance (MR) elastography is increasingly used to non-invasively assess tissue viscoelasticity. However, solid stress and interstitial fluid pressure measurements are performed with invasive methods...
Preprint
Full-text available
Using shear wave elastography, we measure the changes in the wave speed with the stress produced by a striated muscle during isometric voluntary contraction. To isolate the behaviour of an individual muscle from complementary or antagonistic actions of adjacent muscles, we select the flexor digiti minimi muscle, whose sole function is to extend the...
Article
Full-text available
Background Diaphragm dysfunction is highly prevalent in mechanically ventilated patients. Recent work showed that changes in diaphragm shear modulus (ΔSMdi) assessed using ultrasound shear wave elastography (SWE) are strongly related to changes in Pdi (ΔPdi) in healthy subjects. The aims of this study were to investigate the relationship between ΔS...
Article
Passive cavitation detection can be performed to monitor microbubble activity during brain therapy. Microbubbles under ultrasound exposure generate a response characterized by multiple nonlinear emissions. Here, the wide bandwidth of capacitive micromachined ultrasonic transducers (CMUTs) was exploited to monitor the microbubble signature through a...
Article
Hybridization of positron emission tomography (PET) with other functional neuroimaging techniques such as functional magnetic resonance imaging (fMRI) or functional ultrasound (fUS) still raises technical and methodological challenges. Beyond the co-registration of anatomical images with functional data, development of hybrid imaging systems has pa...
Article
No PDF available ABSTRACT The complex structure of the skull bone, reflected in particular by spatial variations in thickness and density, leads to a heterogeneity of its acoustic properties. This results in a strong attenuation as well as specific phase shifts of the ultrasonic wave during its crossing, leading to a defocusing of the beam. The imp...
Article
Key points: Twitch transdiaphragmatic pressure elicited by cervical magnetic stimulation of the phrenic nerves is a fully non-volitional method for assessing diaphragm contractility in humans, yet it requires invasive procedures such as oesophageal and gastric catheter balloons. Ultrafast ultrasound enables a very high frame rate allowing the capt...
Article
We present a new, to the best of our knowledge, method to perform acousto-optic imaging based on a spatiotemporal structuration of long-duration acoustic plane waves. This approach is particularly relevant when using detectors with long integration times. We show how it is possible to reconstruct an image by measuring its two-dimensional Fourier co...
Article
Full-text available
The multidrug resistance-associated protein 2 (MRP2) mediates the biliary excretion of drugs and metabolites. [99mTc]mebrofenin may be employed as a probe for hepatic MRP2 activity because its biliary excretion is predominantly mediated by this transporter. As the liver uptake of [99mTc]mebrofenin depends on organic anion-transporting polypeptide (...
Article
Full-text available
We investigated the in vivo effects of voluntary fatiguing isometric contractions of the knee extensor muscles on the viscoelastic properties of the vastus lateralis (VL). Twelve young males (29.0 ± 4.5 years) performed an intermittent voluntary fatigue protocol consisting of 6 sets × 10 repetitions of 5-s voluntary maximal isometric contractions w...
Article
Purpose To investigate the diagnostic accuracy of applying four levels of manual pressure in Shear Wave Elastography (SWE) of the breast and to assess inter-rater reliability. Materials and Methods Single-center prospective preliminary study including patients receiving ultrasound examination of breast lesions as part of routine clinical practice....
Preprint
Full-text available
Angiogenesis, the formation of new vessels, is one of the key mechanisms in tumor development and an appealing target for therapy. Non-invasive, high-resolution, high sensitivity, quantitative 3D imaging techniques are required to correctly depict tumor heterogeneous vasculature over time. Ultrafast Doppler was recently introduced and provides an u...
Article
Background and objective: Different biological models have shown how mechanical stimulation may induce physiological responses from solicited cells, tissues, or organs. In models of cultured skin cells, the frequency of the mechanical stress appears to be a paramount parameter, generating a biological response in some cells, particularly from derm...
Article
We present an experimental investigation of Rayleigh-like wave propagation along the surface of a dense granular suspension. Using an ultrafast ultrasound scanner, we monitor the softening of the shear modulus via the Rayleigh-like wave velocity slowdown in the optically opaque medium as the driving amplitude increases. For such nonlinear behavior...
Article
Full-text available
Ultrasound-modulated optical tomography (UOT) is an imaging technique that couples light and ultrasound in order to perform in-depth imaging of highly scattering media. In previous work, we introduced plane wave UOT, an imaging method analogous to x-ray tomography based on the filtered backprojection for image reconstruction. Angle-limited measurem...
Article
Full-text available
The paraspinal compartment acts as a bone–muscle composite beam of the spine. The elastic properties of the paraspinal muscles play a critical role in spine stabilization. These properties depend on the subjects’ posture, and they may be drastically altered by low back pain. Supersonic shear wave elastography can be used to provide quantitative sti...
Article
The reference method for the assessment of diaphragm function relies on the measurement of transdiaphragmatic pressure (Pdi). Local muscle stiffness measured using ultrafast shear wave elastography (SWE) provides reliable estimates of muscle force in locomotor muscles. This study aimed at investigating whether SWE could be used as a surrogate of Pd...
Article
Angiogenesis, the formation of new vessels, is one of the key mechanisms in tumor development and an appealing target for therapy. Non-invasive, high-resolution, high-sensitivity, quantitative 3-D imaging techniques are required to correctly depict tumor heterogeneous vasculature over time. Ultrafast Doppler was recently introduced and provides an...
Article
2 D shear wave elastography (2D-SWE) is the latest evolution of elastography techniques and allows real-time quantitative assessment of the medium stiffness. The aim of this review is to identify, describe, explain and illustrate some technical restrictions and artifacts in 2D-SWE. Encountered artifacts and technical restrictions may be categorized...
Article
We prospectively evaluated the performance of combined shear wave elastography (SWE) and conventional ultrasound (US) for the characterization of 89 testicular focal masses. Testes were evaluated with B-mode, color Doppler and SWE measurements, locating a region of interest on the normal and pathologic parenchyma. Thirty-seven malignant tumors (MTs...
Article
Background: Varicocele is among the most common causes of male infertility because of various mechanism, including hypoxia. Purpose: To evaluate testicular vascularization (TV) with ultrasensitive Doppler before and during the Valsalva maneuver (VM) and correlate TV changes to varicocele's spermatic venous reflux graduated by color Doppler. Mat...
Article
Purpose To evaluate the ability of a new ultrasound (US) method based on sound speed estimation (SSE) with respect to the detection, quantification, and grading of hepatic steatosis using magnetic resonance (MR) proton density fat fraction (PDFF) as the reference standard and to calculate one US fat index based on the patient’s SSE. Materials and M...
Chapter
The supersonic shear imaging (SSI) technique allows quantitative and real‐time imaging of elasticity by judiciously using radiation pressure to generate a shear wave and ultrafast imaging for acquisition. The basis of the SSI technique is to use radiation force to excite the medium. The idea of the SSI technique is to use ultrafast imaging by illum...
Chapter
This chapter describes how transient elastography techniques can be adapted to study the anisotropic shear moduli of simple muscles in vitro and in vivo. It presents theoretical considerations from general to hexagonal anisotropic medium, also called a transverse isotropic medium and predicts the existence of a slow and a fast shear wave in biologi...
Chapter
Many ultrasound elastography methods rely on the transmission characteristics to rheologically define biological tissues, and analyze how they are behaving in comparison to healthy tissue parameters. This process is supported by a very strong mathematical basis ‐ a toolkit of equations that describe the laws of mechanical wave propagation. The equa...
Chapter
In vivo muscle biomechanical properties have been classically inferred from inverse dynamics or measurements of joint torque performed using ergometers. This chapter focuses on the supersonic shear imaging technique in musculoskeletal applications. It also focuses on the use of the supersonic shearwave imaging (SSI) technique that provides a quanti...
Preprint
Full-text available
We present an experimental investigation of shear elastic wave propagation along the surface of a dense granular suspension. Using an ultrafast ultrasound scanner, we monitor the softening of the shear wave velocity inside the optically opaque medium as the driving amplitude increases. For such nonlinear behavior two regimes are found: in the first...
Article
Full-text available
The non-invasive quantification of human tissue fat fraction using easily scalable and accessible imaging technologies is crucial for the diagnosis of many diseases including liver steatosis. Here, we propose a non-invasive quantification of fat content using a highly accessible ultrasonic imaging technology. Ultrasonic echoes backscattered from hu...
Chapter
Finding new parameters to improve diagnosis for physicians is challenging. So, the evaluation of quantified nonlinear shear parameters could help to answer this need. Different methods allow one to estimate nonlinear parameters, acoustoelasticity theory, high amplitude shear waves propagation, or nonlinear interaction of shear wave. However, assess...
Chapter
The wave equation can be expressed in terms of the different pair parameters of elastic properties of tissue. It was shown that two types of waves propagate in the solid: compressional waves and shear waves. The behavior of the solid is then described by the expression of the complex shear modulus. The complex shear modulus can simplify the notatio...
Article
Ultrasound Elastography for Biomedical Applications and Medicine Ivan Z. Nenadic, Matthew W. Urban, James F. Greenleaf, Mayo Clinic Ultrasound Research Laboratory, Mayo Clinic College of Medicine, USA Jean-Luc Gennisson, Miguel Bernal, Mickael Tanter, Institut Langevin Ondes et Images, ESPCI ParisTech CNRS, France Covers all major developments and...
Article
Full-text available
Diffuse optical tomography (DOT) is a reliable and widespread technique for monitoring qualitative changes in absorption inside highly scattering media. It has been shown, however, that acousto-optic (AO) imaging can provide significantly more qualitative information without the need for inversion algorithms due to the spatial resolution afforded b...
Article
Full-text available
The assessment of myocardial fiber disarray is of major interest for the study of the progression of myocardial disease. However, time-resolved imaging of the myocardial structure remains unavailable in clinical practice. In this study, we introduce 3D Backscatter Tensor Imaging (3D-BTI), an entirely novel ultrasound-based imaging technique that ca...
Article
Full-text available
The functional mapping of brain activity is essential to perform optimal glioma surgery and to minimize the risk of postoperative deficits. We introduce a new, portable neuroimaging modality of the human brain based on functional ultrasound (fUS) for deep functional cortical mapping. Using plane-wave transmissions at an ultrafast frame rate (1 kHz)...
Data
Transcranial functional ultrasound (fUS) imaging in an awake and freely moving mouse using our newly developed ultralight ultrasonic probe and fixation setup.
Article
Background Ultrasensitive Doppler is a novel non-invasive ultrasound (US) Doppler technique that improves sensitivity and resolution for the detection of slow flow. Purpose To investigate the feasibility of ultrasensitive Doppler (USD) for testicular disease diagnosis, using both qualitative and quantitative results. Material and Methods This pro...
Article
A recent ultrasound imaging technique—shear wave elastography—showed its ability to image and quantify the mechanical properties of biological tissues, such as prostate or liver tissues. In the present study this technique was used to evaluate the relationship among tumor growth, stiffness and reduction of treatment with combretastatin (CA4 P) in a...
Poster
Full-text available
Purpose: The development of new innovative therapies implies to monitor activity in the whole visual brain system with high spatial and temporal resolutions. To increase the resolution obtained with fMRI, we investigated if the new functional imaging technique based on ultrasounds (US) can accurately map activity in the Visual Cortex (VC), Superior...
Article
Full-text available
Functional ultrasound (fUS) imaging by ultrasensitive Doppler detection of blood volume was reported to measure adult rat brain activation and functional connectivity with unmatched spatiotemporal sampling (100 µm, 1 ms), but skull-induced attenuation of ultrasonic waves imposed skull surgery or contrast agent use. Also, fUS feasibility remains to...
Article
Longitudinal imaging techniques are needed that can meaningfully probe the tumor microenvironment and its spatial heterogeneity. Contrast-enhanced ultrasound, shear wave elastography and quantitative ultrasound are ultrasound-based techniques that provide information on the vascular function and micro-/macroscopic tissue structure. Modifications of...
Data
"3D fUS imaging of the rat brain structures responding to visual stimuli. Responding areas, left and right visual cortices, Superior Colliculus and LGN, were manually superimposed to a Calabrese rat brain model. Thus allowing 3D visualization in depth in the brain or along different coronal cross-sections.".
Article
Full-text available
Hepatic steatosis is a common condition, the prevalence of which is increasing along with non-alcoholic fatty liver disease (NAFLD). Currently, the most accurate noninvasive imaging method for diagnosing and quantifying hepatic steatosis is MRI, which estimates the Proton-Density Fat Fraction (PDFF) as a measure of fractional fat content. However,...
Article
Full-text available
3D functional imaging of the whole brain activity during visual task is a challenging task in rodents due to the complex tri-dimensional shape of involved brain regions and the fine spatial and temporal resolutions required to reveal the visual tract. By coupling functional ultrasound (fUS) imaging with a translational motorized stage and an episod...
Article
Noninvasive evaluation of the rheological behavior of soft tissues may provide an important diagnosis tool. Nowadays, available commercial ultrasound systems only provide shear elasticity estimation by shear wave speed assessment under the hypothesis of a purely elastic model. However, to fully characterize the rheological behavior of tissues, give...