X-Ray Tomography Group
Prof. Stampanoni heads a group of over 20 people, including three staff scientists, two technicians, one controls engineer, and many postdocs and PhD students. The team focuses on the development of tools, both instrumentation and algorithms, for tomographic X-ray imaging, exploiting synchrotron and laboratory sources. The group is engaged in the design and construction of ultra-fast data acquisition systems (stroboscopic coherent X-ray radiology and tomography) to provide dynamic investigation of rapidly evolving systems. The group also intensively develops optimized applications for fast, concurrent post-processing of tomographic data starting from simple normalization corrections to ad-hoc reconstruction and artifact reductions algorithms. Finally, the group investigates, creates and optimizes novel imaging modalities based on the coherent properties of synchrotron radiation and works on the transition of such work to conventional x-ray sources.
Scientific Highlights
3D printing silica aerogels at the micrometer scale
A group of EMPA and ETH Zürich researchers have developed a new method to directly write ink made of silica aerogels in 3D. Thanks to X-ray phase contrast tomography at the TOMCAT beamline they characterized the resulting printed material with different compositions. Their results were published in Nature on August 18, 2020.
Phase contrast microtomography reveals nanoparticle accumulation in zebrafish
Metal-based nanoparticles are a promising tool in medicine – as a contrast agent, transporter of active substances, or to thermally kill tumor cells. Up to now, it has been hardly possible to study their distribution inside an organism. Researchers at the University of Basel in collaboration with the TOMCAT team have used phase contrast X-ray tomographic microscopy to take high-resolution captures of the nanoparticle aggregation inside zebrafish embryos.
The study was published in the journal Small and featured on the cover of its current issue.
Miniaturized fluidic circuitry observed in 3D
The team of Prof. Thomas Hermans at the University of Strasbourg in France managed to create wall-less aqueous liquid channels called anti-tubes. Thanks to X-ray phase contrast tomography at the TOMCAT beamline those anti-tubes could be observed in 3D. The exciting results were published in Nature on May 6, 2020.
X-ray Imaging for Biomedicine: Imaging Large Volumes of Fresh Tissue at High Resolution
The TOMCAT beamline at the Swiss Light Source specializes in rapid high-resolution 3-dimensional tomographic microscopy measurements with a strong focus on biomedical imaging. The team has recently developed a technique to acquire micrometer-scale resolution datasets on the entire lung structure of a juvenile rat in its fresh natural state within the animal’s body and without the need for any fixation, staining or other alteration that would affect the observed structure (E. Borisova et al., 2020, Histochem Cell Biol).
4 times compression factor for tomographic data feasible
In a recent study, TOMCAT has shown that lossy compression by a factor of at least 3 to 4 of raw acquisitions generally does not affect the reconstruction quality and that higher factors (six to eight times) can be achieved for tomographic volumes with a high signal-to-noise ratio as it is the case for phase-retrieved datasets. This finding is relevant to current challenges on large tomography data management and storage especially at synchrotron facilities. The results of this study was published in Journal of Synchrotron Radiation.
Looking into the hints of early breast cancer detection
Microcalcifications are the most important indicator in the diagnosis of early breast cancer. The team of X-ray tomography group, in collaboration with Kantonsspital Baden, has carried out a reader study to characterize microcalcifications non-invasively using grating interferometry. This study reveals a potential way to discriminate benign and malignant lesions at early stage.
A new etcher is just unpacked!
TOMCAT has a new etcher tool for the fabrication of very high aspect ratio gratings in silicon. The new SPTS Rapier system for silicon deep reactive ion etching just arrived and unpacked from the crate in front of the Laboratory of Micro and Nanotechnology at PSI! We thank the LMN technical staff for the support and the great job of moving in!
How to correct beam hardening effects in dual phase grating interferometry?
Researchers at the X-ray tomography group have expanded the theoretical understanding of dual phase grating interferometry with polychromatic sources. As a result, beam hardening effects can be corrected and a real space correlation function of a sample can be retrieved in dark-field imaging. These are significant steps towards application of the method for the quantitative investigation of microstructures of materials and devices using dual phase grating interferometry. The results of the work were published in Optics Express on June 12, 2020.
Rapid 3D directional small-angle scattering imaging achieved at TOMCAT
Researchers from the TOMCAT beamline have developed a small-angle scattering tensor tomography method to visualize microscopic features within a macroscopic field of view with unprecedented data acquisition speed. The results of the study were published in Applied Physics Letters on April 1, 2020.
SNF funds dynamic X-ray imaging of the human auditory system in motion
In collaboration with clinicians from the Inselspital and engineers of the University Hospital of Bern, the X-Ray Tomography Group will be part of a new SNF project entitled “The Human Auditory System in Motion: Direct Observation of the Microfunction of Sound Transmission using Dynamic Phase-contrast X-ray Imaging”.