Contact: Prof. Dr. Marina Eckermann
One type of electromagnetic waves are X-rays. With their short wavelength, hard X-rays can penetrate matter such as biological tissues deeply, and provide information about its interior architecture at sub-micrometric resolution. This is exploited in computed tomography (CT), a technique to retrieve three-dimensional images of samples. Traditionally, the image contrast in CT relies on the absorption within the sample, the complex part of the refractive index. However, soft tissues absorb X-rays little only, providing little absorption contrast. Here, the real part of the complex refractive index can provide much more insights into the sample architecture: Propagation-based X-ray phase-contrast CT (PC-CT) or holographic X-ray CT (holo-CT) is a special case of X-ray imaging, which relies on self-interfering wavefronts, and requires no or little contrast agents. In the context of biomedical tissues, due to its analogy to pathological histology, this is often referred to as “three-dimensional virtual histology”.
Beside such full-field X-ray imaging, there are further techniques to probe biomedical samples with hard X-rays, such as: X-ray scattering (SAXS, WAXS), X-ray fluorescence imaging (XRF), X-ray ptychography or X-ray crystallography.
We use and develop X-ray based methods in order to characterize biomedical samples. We also work on multi-modal approaches, combining different X-ray based methods or with other techniques pioneered at the IAP, or also conventional histology, electron microscopy, etc.
Our mission is the characterization of biomedical structures, where one important field of application is the identification of pathological mechanisms in order to decipher diseases.
Here, we work at different ends:
-
- Identification of sample systems & optimized sample preparation
- Development of our home-built X-ray CT setup
- Experiments at large-scale research facilities, esp. synchrotron facilities
- Development of data processing workflows and innovative mathematical tools for data analysis
