Development of Novel X-Ray Imaging Methods for Biomedical Applications
Prof. F. Pfeiffer, TUM
Since its discovery more than a hundred years ago x-ray radiation has become an indispensable tool in medical diagnostics. Despite its invaluable contribution to patient care, for example in imaging bone structure, x-ray diagnostics ultimately reaches its limits in the examination of soft tissue, such as tumors in healthy tissue. Coherent phase-contrast x-ray methods, which explicitly utilize the wave character of x-ray light, provide a marked improvement in image quality.
However, the requirements of existing - crystal- or propagation-based - phase-contrast imaging methods have so far restricted the application to large-scale accelerator synchrotron sources, which deliver a mainly coherent and monochromatic x-ray beam. To circumvent the problem, the Pfeiffer group is developing alternative approaches, based on x-ray optical gratings. These novel approach can efficiently yield quantitative differential phase-contrast images utilizing incoherent, broadband x-ray sources, as presently employed in medical imaging. Several proof-of-principle experiments carried out by Pfeiffer and co-workers at large-scale synchrotrons, table-top Thomson x-ray sources, and conventional x-ray tube apparatus have demonstrated the extensive and highly promising application potential of these novel methodological developments.
In addition to these efforts directed towards pre-clinicial and clinical applications of novel phase-contrast x-ray imaging methods the Pfeiffer group pioneers research in the area of novel coherent super-resolution x-ray microscopy methods for applications in x-ray nanotomography.
References - Selection:
- F. Pfeiffer et al., Nature Materials 7, 134-137 (2008)
- F. Pfeiffer et al., Physical Review Letters 101, 16810 (2008)
- F. Pfeiffer et al., Physics in Medicine and Biology 52, 6923 (2007)
- F. Pfeiffer et al., Nature Physics 2, 258-261 (2006)
- T. Weitkamp et al., Optics Express 13, 6296-6304 (2005)
Contribution to IMPRS curriculum:
Lecturer: Franz Pfeiffer (2 SWS lecture + 2 SWS exercises)
The course ‘Modern X-ray Physics’ will cover some of the basics of x-ray related science. Starting with the basics of x-ray generation (from x-ray tubes and synchrotron radiation facilities) and interaction with matter (absorption and scattering), a range of topics in the field is covered, including refraction, diffraction and spectroscopy. The properties of an x-ray beam will be described in terms of flux, coherence, divergence and spectral bandwidth, and these properties are then used in the description of x-ray application to medical imaging, x-ray microscopy and coherent diffraction. Further, the developments of new x-ray sources such as Free Electron Lasers and Inverse Compton Sources, and the concepts of using x-ray optics to manipulate the beam properties into a desirable state and shape are covered.