Synchrotron X-ray Phase Contrast micro-tomography, as implemented at the TOMCAT beamline (PSI), provide essential and unique 3D reconstructions of complete hearts (see figure) for understanding cardiac microstructure and its influencing factors, both on small animals or human fetal hearts. The aim of our current Heart Imaging Project is to quantify cardiac structures and tissues for the first time at micrometre scale, non-destructively, without the use of contrast agents and in 3D.
The main goal of this project is to propose X-ray phase contrast imaging as a fast complementary cost-effective non-destructive 3D quantitative approach for diagnosis in human EMBs and full thickness samples. Synchrotron propagation-based phase contrast imaging is used in order to identify meaningful markers at different stages of pathological remodelling and thus provide a detailed characterization of normal/abnormal tissue samples. This information will be useful for a future implementation of the techniques in the clinics, potentially by means of lab-source based grating interferometry.
The goal of this project is to implement a PIHS at the TOMCAT beamline, which will allow to dynamically study the heart, without the complications that an in vivo experiment might introduce. Such implementation includes the development of hardware for the experimental setup, as well as the design of acquisition protocols, image reconstruction and image processing, which are challenging in fast dynamical acquisitions due to reduced signal-to-noise ratio (SNR). These developments will be used to investigate global heart behavior and analyse cardiomyocyte aggregates orientation evolution during the heartbeat.
The global energy system relies strongly on fossil fuels. Their expected reduced availability and detrimental environmental impact call for alternative energy solutions. Polymer Electrolyte Fuel Cells (PEFC) are a promising technology for future energy sources, especially in decarbonizing the mobility sector. The aim of this project is to develop sub-second tomographic microscopy for PEFC in order to detect the liquid water dynamics in the gas diffusion layers (GDL), the key component regulating water management during cell operation.
Taking advantage of the recent development of efficient projectors, we are aiming at a highly flexible parallel iterative reconstruction framework, where the different algorithm components (e.g. projectors, regularizers and solvers) can be easily interchanged and therefore the reconstruction schemes easily optimized for each single experiment. In addition to enabling the reconstruction of a large variety of datasets, this flexible solution will provide invaluable insight and hands-on experience important for defining future directions.
At modern third generation synchrotron sources, voxel sizes in the micrometer range are routinely achieved. However, isotropic 100 nm barrier is reached and surpassed by only a few instruments. At the TOMCAT beamline of the Swiss Light Source, the multimodal endstation (which offers tomographic capabilities in the micron range) is equipped with a full field, hard X-ray nanoscope. The ongoing efforts aim to further improve the hard components (optics and setup versatility) as well as data acquisition speed, spatial resolution and sensitivity.
In the context of the SLS2.0 upgrade project, the possibility to gain, in addition to the microstructure, information on the elemental distribution in a rapid manner is explored. We aim at combining energy resolved 2D detectors (e.g. Mönch) with pinholes in a camera obscura geometry. We are currently assessing the achievable spatial, temporal and energy resolution as well as the sensitivity of such a system as well as developing the required reconstruction and data processing tools. Finally, the most suitable applications are also explored.
