Évaluation des potentialités de l'IRM pour la recherche sur la Physiologie des Bivalves Premiers résultats anatomiques et perspectives

Nuclear Magnetic Resonance (NMR) is increasingly used in biology and the appearance of imaging and structural and/or metabolic spectroscopy (MRI/MSR) platforms (Rennes, Strasbourg, Marseille...) devoted to this small animal shows the recent keen interest in these research techniques. However, to this day and to our knowledge, no approach of this style has been developed for sea molluscs and even less so for the cup oyster, Crassostrea gigas. Because of its economic importance, this bivalve mollusc is the subject of much research in physiology, to the point of becoming, at IFREMER, a biological model for marine invertebrates. Nonetheless, most of the methodologies developed for studying it are destructive, which (1) prevents individual follow-up, (2) limits, indeed, prevents our understanding of certain biological processes and (3) requires the setting-up and maintenance of experimental populations at high cost. In terms of technological innovation, it seemed to us necessary to perform a preliminary technological evaluation of the MRI's possibilities. This report therefore presents the preliminary results on Nuclear Magnetic Resonance imaging obtained about the cup oyster. H is a summary of research conducted in collaboration with two teams from Rennes (CEMAGREF and CHU) since 2002 and clearly shows the feasibility and the exceptional interest of this technique for the study of the cup oyster's physiology. This report only presents the results of morphological and parametric imaging. These results constitute a basis for research but are probably anecdotal with respect to the possibilities of functional (or metabolic) imaging in vivo. We propose to make this approach the subject of upcoming research in 2004-2005. In addition, we used low and mid-field MRIs (0.2T and 1.5T). An evaluation of the possibilities of a high field (4.7T) MRI has also proven to be one of the upcoming priorities in terms of high-resolution anatomical imaging (creation of a digital atlas of the cup oyster).