Denis Le Bihan


Denis Le Bihan is a medical doctor, physicist, member of the Institut de France, member of the French Academy of Technologies and director since 2007 of NeuroSpin, an institution of the Atomic Energy and Alternative Energy Commission in Saclay, dedicated to the study of the brain by magnetic resonance imaging 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, the coveted Lounsbery Prize, the Louis D. Prize from the Institut de France and the prestigious Honda Prize. His work has focused on the introduction, development and application of highly innovative methods, notably diffusion MRI.

Biography

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 with the specialty "radiology". He also follows a course in human biology. 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. In 1987, he joined the National Institutes of Health in Bethesda, Maryland, USA, where he remained until 1994. This is where he continues to develop diffusion MRI, introducing diffusion tensor MRI 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. 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.
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.

Scientific Works

Denis Le Bihan is particularly recognized for his pioneering work on diffusion MRI, a concept whose principles he established and demonstrated its potential, 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. Diffusion MRI is also of great importance outside the brain for the detection and monitoring of cancers and metastases.

Diffusion MRI and Stroke

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 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 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.

Intracerebral connectivity

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, in a way that is totally harmless to patients. 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. With the diffusion tensor MRI technique developed by Denis Le Bihan and Peter Basser at the NIH in 1992 and its variants developed since then, it is now possible to obtain atlases of intracerebral connections with very high accuracy. Diffusion MRI can therefore not only diagnose and study white matter fibre disorders, but also subtle connection abnormalities in neural circuits. These abnormalities that appear very early in life may reflect some functional disorders or psychiatric conditions. At the other end of life, normal or pathological aging is also accompanied by a rearrangement of brain connections that diffusion MRI shows.

Diffusion MRI and cancer

Diffusion MRI is becoming increasingly important at the beginning of the 21st century in the exploration of cancers, particularly breast, 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. 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 well before clinical improvement, which makes it possible to adapt treatment very early in the absence of a positive response.

Non-professional activities

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 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 with original forecasting tools that he himself has developed since the age of 12.

International recognition

As a pioneer in his field, Denis Le Bihan has received many awards and recognitions during his career21.