[CONFERENCE] IMPLANTEUS LECTURES Perrine Chaurand

20 JANVIER 2021 Avignon Université.

Using medical imaging methods in environmental sciences

• Perrine CHAURAND (CEREGE, Aix en Provence):

X-ray imaging in 2D and 3D: multi-scale and correlative approach coupling X-ray fluorescence and tomography techniques. Applications in environmental science

Perrine CHAURAND,   https://www.cerege.fr/en/users/perrine-chaurand

Since 2007, engineer at CEREGE- Aix Marseille University, Aix-en-Provence. In charge of the 2D&3D X-ray imaging platform MATRIX, https://www.cerege.fr/fr/matrix
Academic background: Engineer in Chemical Engineering, Dr. in Geosciences of Environment.
Expertise: Physico-chemistry characterization of heterogeneous and divided solids (waste, nanomaterials …) with a multi-scale approach. X-ray techniques (micro-analyses, mapping and 3D imaging). Speciation of trace elements (X-ray absorption spectroscopy).
X-ray imaging in 2D and 3D: multi-scale and correlative approach coupling X-ray fluorescence and tomography techniques. Applications in environmental science.
Abstract:
2D and 3D X-ray imaging at high spatial resolution (i.e. micrometric and nanometric scale) represents the heart of the MATRIX platform located at CEREGE (Aix en Provence, France). MATRIX brings together in the same laboratory high-performance X-ray tools: two X-ray tomographs, several X-ray micro-fluorescence spectrometers and an X-ray diffractometer. These tools offer the opportunity to visualize in 2 and/or 3 dimensions the structural, the mineralogical and the chemical heterogeneity of very varied samples (geological samples, materials, biological samples, soft tissues, etc.). The use of X-ray radiation avoids the delicate and time-consuming preparations of other observation methods (such as electron microscopy) and the integrity of the samples is, in many cases, preserved.

X-ray tomography is a powerful 3D imaging technique for the in-situ and non-destructive investigation of the inner structure of an object. This relatively recent technique has tremendously evolved over the past decade with much more sensitive detection systems and increased spatial resolution. Indeed, it is now possible to reach spatial resolution of tens of nanometers with synchrotron X-ray source but also with lab-based systems (called nano-tomograph). The MATRIX platform is equipped with two X-ray tomographs, a micro-tomograph and a nano-tomograph, that offer the opportunity to perform multi-scale analysis on the same sample from several tens of microns up to 50 nm.
3D micro and nano-structural observations can also be integrated in a correlative approach by coupling X-ray tomography with 2D chemical mapping (X-ray fluorescence micro-spectroscopy, micro-XRF).

This lecture will introduce these X-ray imaging techniques: theoretical principles, operating mode and systems. Some examples of applications in environmental science (with a specific focus on the analysis of soft tissues as plants, organisms, organs or cells) will be detailed to illustrate the advantage and performance of a multi-scale and correlative approach.