Denis Le Bihan | |
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Born | 30 July 1957 67) | (age
Awards | [Honda Prize, Louis-Jeantet Award, Rhein Foundation Award] |
Denis Le Bihan (born 30 July 1957) is a medical doctor, physicist, member of the Institut de France (French Academy of sciences), [1] member of the French Academy of Technologies and director since 2007 of NeuroSpin, an institution of the Atomic Energy and Alternative Energy Commission (CEA) in Saclay, dedicated to the study of the brain by magnetic resonance imaging (MRI) with a very high magnetic field. Denis Le Bihan has received international recognition for his outstanding work, introducing new imaging methods, particularly for the study of the human brain, as evidenced by the many international awards he has received, such as the Gold Medal of the International Society of Magnetic Resonance in Medicine (2001), [2] the coveted Lounsbery Prize (US National Academy of Sciences and French Academy of sciences 2002), the Louis D. Prize from the Institut de France [3] (with Stanislas Dehaene, 2003), the prestigious Honda Prize (2012), [4] the Louis-Jeantet Prize (2014), the Rhein Foundation Award (with Peter Basser) (2021). His work has focused on the introduction, development and application of highly innovative methods, notably diffusion MRI. [5]
Denis Le Bihan studied medicine and physics in Paris. After an internship in neurosurgery, radiology and nuclear medicine, he obtained his doctorate in medicine in 1984 (University of Paris VI) with the specialty "radiology". He also follows a course in human biology (functional explorations of the nervous system, mathematical models in medicine). His training in physics focuses on nuclear physics and elementary particles. He obtained his doctorate in physics in 1987, his thesis focusing on a completely new method of magnetic resonance imaging that he introduced and developed (diffusion imaging and IVIM imaging (en) for IntraVoxel Incoherent Motion). In 1987, he joined the National Institutes of Health (NIH) in Bethesda, Maryland, USA, where he remained until 1994. This is where he continues to develop diffusion MRI, introducing diffusion tensor MRI (DTI) with Peter Basser. Denis Le Bihan joined the Frédéric Joliot Hospital Service of the CEA in 1994 to head the anatomical and functional neuroimaging laboratory. In 2000, he became Director of the Federal Institute for Research in Functional Neuroimaging (IFR 49). He presided over the founding and opening of NeuroSpin in 2007 and has been its director since then. Since 2005, Denis Le Bihan has also been a regular guest professor at Kyoto University (Human Brain Research Center).
NeuroSpin has been able to mobilize significant public funding to conduct innovative research in neurodegenerative disease imaging. As part of the Franco-German Iseult NeuroSpin project, CEA teams are in the process of finalizing the construction of a unique MRI scanner using a record magnetic field of 11.7 teslas, thanks to a magnet of more than 100 tons with an original design. [6]
Denis Le Bihan is particularly recognized for his pioneering work on diffusion MRI, a concept whose principles he established [7] and demonstrated its potential, [8] particularly in the medical field during the 1980s. Since then, Denis Le Bihan has continued to develop and perfect the method, and has further extended its fields of application. Diffusion MRI is used worldwide to study the anatomy of our brain, its connections and functioning. In medicine, major neurological applications include acute stroke and white matter disorders, including psychiatric disorders. [9] Diffusion MRI is also of great importance outside the brain for the detection and monitoring of cancers and metastases. [10]
Diffusion MRI allows us to detect in the context of the emergency, a few hours after the onset of a stroke, the area of the brain that is dying because it is deprived of blood flow when a blood vessel has been obliterated by a clot. The consequences of stroke are formidable: it is the third leading cause of death, and in 30% of cases it leaves severe functional sequelae (hemiplegia, speech disorders) in patients who become unable to support themselves. Stroke is by far the leading source of disability in the long term, with significant social and economic consequences. Diffusion MRI has led to the urgent and accurate identification of stroke [11] and the development of drugs that, injected in the very first hours following stroke, can dissolve the clot and immediately clear up symptoms. The vast majority of MRI scanners manufactured and installed worldwide are equipped with the diffusion MRI method introduced by Denis Le Bihan.
The brain contains about 100 billion neurons, our grey matter, which are connected to each other at a rate of 1,000 to 10,000 connections per neuron through extensions called axons that constitute the fibres of the white matter. The diffusion MRI made it possible, for the first time, to produce 3D images of these connections (tractography), in a way that is totally harmless to patients (just lie down for about ¼ hours in the MRI scanner). The principle is based on the fact that the diffusion of water is slower perpendicular to the fibres. It is therefore sufficient to obtain images of the diffusion of water in different directions to account for the orientation of the fibres, which Denis Le Bihan's team first showed in 1991. [12] With the diffusion tensor MRI technique (DTI) developed by Denis Le Bihan and Peter Basser at the NIH in 1992 [13] [14] and its variants developed since then (high angular resolution methods), it is now possible to obtain atlases of intracerebral connections with very high accuracy. [15] Diffusion MRI can therefore not only diagnose and study white matter fibre disorders (such as multiple sclerosis), but also subtle connection abnormalities in neural circuits. These abnormalities that appear very early in life may reflect some functional disorders (dyslexia) or psychiatric conditions (schizophrenia, autism). At the other end of life, normal or pathological aging (neurodegenerative diseases, such as Alzheimer's disease) is also accompanied by a rearrangement of brain connections that diffusion MRI shows. [16]
Diffusion MRI is becoming increasingly important at the beginning of the 21st century in the exploration of cancers, particularly breast, [17] prostate and liver cancers. While diffusion MRI is mainly used for the brain, Denis Le Bihan's first trials actually focused on the liver to identify tumours and distinguish them from vascular malformations. [18] The proliferation of cells in cancers and metastases are all obstacles to the diffusion of water, which slows down. Diffusion MRI therefore makes it possible to identify these cancerous lesions and to judge the effect of treatments (such as chemotherapy) well before clinical improvement, which makes it possible to adapt treatment very early in the absence of a positive response.
Denis Le Bihan is passionate about music and an experienced amateur pianist who occasionally gives concerts on a voluntary basis. He is also an experienced photographer: he exhibited an extract of his works (photos of Kyoto) in November 2011 at the French Institute of Japan – Kansai in honour of the victims of the Pacific Coast earthquake at Tōhoku He is also at the origin of a weather forecast website (updated daily with a 6-day window, for the moment for the West Paris region) with original forecasting tools that he himself has developed since the age of 12. [19]
As a pioneer in his field, Denis Le Bihan has received many awards and recognitions during his career.
Denis Le Bihan is a prolific author with more than 300 publications in peer-reviewed scientific journals and a large number of book chapters. He is also the inventor or co-inventor for a dozen patents.
Scientific publications of a historical nature
Books
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body. MRI does not involve X-rays or the use of ionizing radiation, which distinguishes it from computed tomography (CT) and positron emission tomography (PET) scans. MRI is a medical application of nuclear magnetic resonance (NMR) which can also be used for imaging in other NMR applications, such as NMR spectroscopy.
In neuroscience, tractography is a 3D modeling technique used to visually represent nerve tracts using data collected by diffusion MRI. It uses special techniques of magnetic resonance imaging (MRI) and computer-based diffusion MRI. The results are presented in two- and three-dimensional images called tractograms.
Perfusion is the passage of fluid through the circulatory system or lymphatic system to an organ or a tissue, usually referring to the delivery of blood to a capillary bed in tissue. Perfusion may also refer to fixation via perfusion, used in histological studies. Perfusion is measured as the rate at which blood is delivered to tissue, or volume of blood per unit time per unit tissue mass. The SI unit is m3/(s·kg), although for human organs perfusion is typically reported in ml/min/g. The word is derived from the French verb perfuser, meaning to "pour over or through". All animal tissues require an adequate blood supply for health and life. Poor perfusion (malperfusion), that is, ischemia, causes health problems, as seen in cardiovascular disease, including coronary artery disease, cerebrovascular disease, peripheral artery disease, and many other conditions.
Diffusion-weighted magnetic resonance imaging is the use of specific MRI sequences as well as software that generates images from the resulting data that uses the diffusion of water molecules to generate contrast in MR images. It allows the mapping of the diffusion process of molecules, mainly water, in biological tissues, in vivo and non-invasively. Molecular diffusion in tissues is not random, but reflects interactions with many obstacles, such as macromolecules, fibers, and membranes. Water molecule diffusion patterns can therefore reveal microscopic details about tissue architecture, either normal or in a diseased state. A special kind of DWI, diffusion tensor imaging (DTI), has been used extensively to map white matter tractography in the brain.
Magnetic resonance elastography (MRE) is a form of elastography that specifically leverages MRI to quantify and subsequently map the mechanical properties of soft tissue. First developed and described at Mayo Clinic by Muthupillai et al. in 1995, MRE has emerged as a powerful, non-invasive diagnostic tool, namely as an alternative to biopsy and serum tests for staging liver fibrosis.
Kenneth Kin Man Kwong is a Hong Kong-born American nuclear physicist. He is a pioneer in human brain imaging. He received his bachelor's degree in Political Science in 1972 from the University of California, Berkeley. He went on to receive his Ph.D. in physics from the University of California, Riverside studying photon-photon collision interactions.
A connectome is a comprehensive map of neural connections in the brain, and may be thought of as its "wiring diagram". An organism's nervous system is made up of neurons which communicate through synapses. A connectome is constructed by tracing the neuron in a nervous system and mapping where neurons are connected through synapses.
Magnetic resonance neurography (MRN) is the direct imaging of nerves in the body by optimizing selectivity for unique MRI water properties of nerves. It is a modification of magnetic resonance imaging. This technique yields a detailed image of a nerve from the resonance signal that arises from in the nerve itself rather than from surrounding tissues or from fat in the nerve lining. Because of the intraneural source of the image signal, the image provides a medically useful set of information about the internal state of the nerve such as the presence of irritation, nerve swelling (edema), compression, pinch or injury. Standard magnetic resonance images can show the outline of some nerves in portions of their courses but do not show the intrinsic signal from nerve water. Magnetic resonance neurography is used to evaluate major nerve compressions such as those affecting the sciatic nerve (e.g. piriformis syndrome), the brachial plexus nerves (e.g. thoracic outlet syndrome), the pudendal nerve, or virtually any named nerve in the body. A related technique for imaging neural tracts in the brain and spinal cord is called magnetic resonance tractography or diffusion tensor imaging.
Magnetic resonance imaging (MRI) is a medical imaging technique mostly used in radiology and nuclear medicine in order to investigate the anatomy and physiology of the body, and to detect pathologies including tumors, inflammation, neurological conditions such as stroke, disorders of muscles and joints, and abnormalities in the heart and blood vessels among others. Contrast agents may be injected intravenously or into a joint to enhance the image and facilitate diagnosis. Unlike CT and X-ray, MRI uses no ionizing radiation and is, therefore, a safe procedure suitable for diagnosis in children and repeated runs. Patients with specific non-ferromagnetic metal implants, cochlear implants, and cardiac pacemakers nowadays may also have an MRI in spite of effects of the strong magnetic fields. This does not apply on older devices, and details for medical professionals are provided by the device's manufacturer.
Robert Turner is a British neuroscientist, physicist, and social anthropologist. He has been a director and professor at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, and is an internationally recognized expert in brain physics and magnetic resonance imaging (MRI). Coils inside every MRI scanner owe their shape to his ideas.
Magnetic resonance imaging of the brain uses magnetic resonance imaging (MRI) to produce high quality two-dimensional or three-dimensional images of the brain and brainstem as well as the cerebellum without the use of ionizing radiation (X-rays) or radioactive tracers.
Intravoxel incoherent motion (IVIM) imaging is a concept and a method initially introduced and developed by Le Bihan et al. to quantitatively assess all the microscopic translational motions that could contribute to the signal acquired with diffusion MRI. In this model, biological tissue contains two distinct environments: molecular diffusion of water in the tissue, and microcirculation of blood in the capillary network (perfusion). The concept introduced by D. Le Bihan is that water flowing in capillaries mimics a random walk (Fig.1), as long as the assumption that all directions are represented in the capillaries is satisfied.
Medical image computing (MIC) is an interdisciplinary field at the intersection of computer science, information engineering, electrical engineering, physics, mathematics and medicine. This field develops computational and mathematical methods for solving problems pertaining to medical images and their use for biomedical research and clinical care.
Val Murray Runge is an American and Swiss professor of radiology and the editor-in-chief of Investigative Radiology. Runge was one of the early researchers to investigate the use of gadolinium-based contrast agents for magnetic resonance imaging (MRI), giving the first presentation in this field, followed two years later by the first presentation of efficacy. His research also pioneered many early innovations in MRI, including the use of tilted planes and respiratory gating. His publication on multiple sclerosis in 1984 represented the third and largest clinical series investigating the role of MRI in this disease, and the first to show characteristic abnormalities on MRI in patients whose CT was negative.
Perfusion MRI or perfusion-weighted imaging (PWI) is perfusion scanning by the use of a particular MRI sequence. The acquired data are then post-processed to obtain perfusion maps with different parameters, such as BV, BF, MTT and TTP.
Wolfgang Grodd is a German neuroradiologist and professor emeritus of the University hospital at the University of Tübingen. He is known for his scientific works on the development and application of structural and functional magnetic resonance imaging in metabolic diseases, sensorimotor representation, language production, and cognitive processing, cerebellum, thalamus, and basal ganglia. Currently, Wolfgang Grodd is a research scientist at the Department of the High-Field MR at the Max Planck Institute for Biological Cybernetics.
The history of magnetic resonance imaging (MRI) includes the work of many researchers who contributed to the discovery of nuclear magnetic resonance (NMR) and described the underlying physics of magnetic resonance imaging, starting early in the twentieth century. One researcher was American physicist Isidor Isaac Rabi who won the Nobel Prize in Physics in 1944 for his discovery of nuclear magnetic resonance, which is used in magnetic resonance imaging. MR imaging was invented by Paul C. Lauterbur who developed a mechanism to encode spatial information into an NMR signal using magnetic field gradients in September 1971; he published the theory behind it in March 1973.
An MRI pulse sequence in magnetic resonance imaging (MRI) is a particular setting of pulse sequences and pulsed field gradients, resulting in a particular image appearance.
Arterial spin labeling (ASL), also known as arterial spin tagging, is a magnetic resonance imaging technique used to quantify cerebral blood perfusion by labelling blood water as it flows throughout the brain. ASL specifically refers to magnetic labeling of arterial blood below or in the imaging slab, without the need of gadolinium contrast. A number of ASL schemes are possible, the simplest being flow alternating inversion recovery (FAIR) which requires two acquisitions of identical parameters with the exception of the out-of-slice saturation; the difference in the two images is theoretically only from inflowing spins, and may be considered a 'perfusion map'. The ASL technique was developed by John S. Leigh Jr, John A. Detre, Donald S. Williams, and Alan P. Koretsky in 1992.
Magnetic resonance fingerprinting (MRF) is methodology in quantitative magnetic resonance imaging (MRI) characterized by a pseudo-randomized acquisition strategy. It involves creating unique signal patterns or 'fingerprints' for different materials or tissues after which a pattern recognition algorithm matches these fingerprints with a predefined dictionary of expected signal patterns. This process translates the data into quantitative maps, revealing information about the magnetic properties being investigated.