Jean Talairach

Jean Talairach (January 15, 1911, Perpignan – March 15, 2007, Paris) was a neurosurgeon who practiced at the Centre Hospitalier Ste. Anne in Paris.

Talairach atlas and Talairach coordinates
Among his contributions to science and applied medicine is the Talairach coordinate system of the human brain, which is used to describe the location of brain structures independent from individual differences in the size and overall shape of the brain. Another signification contribution is toward construction of brain atlases.

The Talairach coordinate system is defined by making two points, the anterior commissure and posterior commissure, lie on a straight horizontal line. Since these two points lie on the midsagittal plane, the coordinate system is completely defined by requiring this plane to be vertical. Distances in Talairach coordinates are measured from the anterior commissure as origin. Talairach coordinates are sometimes also known as stereotaxic coordinates.

By defining standard anatomical landmarks that could be identified on different subjects (the anterior and posterior commissures), it became easier to spatially warp an individual brain image obtained through Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET) and other imaging methods to this 'standard Talairach space'. One can then make inferences about tissue identity at a specific location by referring to the atlas.

One disadvantage of the Talairach coordinate atlas is the approximate method of labeling a tissue-specific Brodmann area based on gross visual inspection rather than histological examination. Additionally, the brain examined for creation of the atlas was a post-mortem sample from a woman with a smaller than average cranium. Indeed, in the forward to their monograph, Talairach & Tournoux note that "Because of the variability in brain size, specifically at the level of the telencephalon, this method is valid with precision only for the brain under consideration." This means that most individual brains must be considerably warped to fit the small size of the atlas, inducing some error.

Nonetheless, the Talairach atlas is an invaluable tool in modern neuroimaging, and paved the way for more representative brain atlases including the MNI atlas from the Montreal Neurological Institute.

The Talairach atlas of anatomy constructed initially for stereotactic and functional neurosurgery is also used in human brain mapping, neuroradiology, medical image analysis, and neuroscience education Cerefy. An enhanced and extended electronic version of this atlas, fully segmented and labeled, is also constructed Cerefy. It is available for various applications on five CD-ROMs distributed by Thieme (the original publisher of the Talairach atlases 1988 and 1993). The CD-ROMs published in 1997, 2004, and 2005 also contain another atlas built by Talairach: the referentially oriented atlas with brain connections.

Literature
J. Talairach and P. Tournoux, "Co-planar Stereotaxic Atlas of the Human Brain: 3-Dimensional Proportional System - an Approach to Cerebral Imaging", Thieme Medical Publishers, New York, 1988

J. Talairach and P. Tournoux, "Referentially Oriented Cerebral MRI Anatomy: An Atlas of Stereotaxic Anatomical Correlations for Gray and White Matter", Thieme Medical Publishers, New York, 1993

Electronic Talairach Atlases on CD-ROMs

W.L. Nowinski, A. Thirunavuukarasuu, A.L. Benabid, "The Cerefy Clinical Brain Atlas: Enhanced Edition with Surgical Planning and Intraoperative Support", Thieme Medical Publishers, New York, 2005

W.L. Nowinski and A. Thirunavuukarasuu, "The Cerefy Clinical Brain Atlas on CD-ROM", Thieme Medical Publishers, New York, 2004

W.L. Nowinski, A. Thirunavuukarasuu, R.N. Bryan, "The Cerefy Atlas of Brain Anatomy: An Introduction to Reading Radiological Scans for Students, Teachers, and Researchers", Thieme Medical Publishers, New York, 2002

W.L. Nowinski, A. Thirunavuukarasuu, D.N. Kennedy, "Brain Atlas for Functional Imaging: Clinical and Research Applications", Thieme, New York, 2000

W.L. Nowinski, R.N. Bryan, R. Raghavan, "The Electronic Clinical Brain Atlas: Multiplanar Navigation of the Human Brain", Thieme Medical Publishers, New York, 1997 (foreword written by Dr. Jean Talairach)