Speaker
Prof.
Julia Herzen
(Biomedical Imaging Physics Physics Department & Munich School of BioEngineering Technical University of Munich)
Description
Recently, novel X-ray staining protocols have been developed, which are able to specifically enhance the contrast for one special type of cell structure (eosin-based stain for cytoplasm[1]; cell-nuclei specific stain based on modified hematein staining [2]). For better understanding of the staining process, a quantitative characterization of those X-ray staining protocols inside the soft tissue is required at high spatial resolution to determine the exact distribution of the stain within the cell structure. Here spatial resolutions between 0.5-5 m are required to visualize the major tissue types in the stained human tissue and at the same time to image a representative fraction of the tissue for good statistics.
The major issue with such a quantitative characterization is the fact that no pure attenuation is available at these high spatial resolutions at highly-brilliant synchrotron sources. The high resolution always comes along with propagation-based phase-contrast effects – the so-called edge enhancement - and requires a phase retrieval. The common phase-retrieval methods for single-distances do not provide quantitative values (e.g. Paganin phase retrieval [3]). The grating-based method can clearly and very accurately separate the attenuation and the phase effects. Here, we will elaborate the potential and the remaining challenges of this imaging modality with regard to a quantitative soft-tissue characterization [4], [5].
[1] M. Busse et al., “Three-dimensional virtual histology enabled through cytoplasm-specific X-ray stain for microscopic and nanoscopic computed tomography,” Proceedings of the National Academy of Sciences, vol. 115, no. 10, p. 201720862, 2018, doi: 10.1073/pnas.1720862115.
[2] M. Müller et al., “Nucleus-specific X-ray stain for 3D virtual histology,” Scientific Reports, vol. 8, no. 1, p. 17855, Dec. 2018, doi: 10.1038/s41598-018-36067-y.
[3] D. Paganin, S. C. Mayo, T. E. Gureyev, P. R. Miller, and S. W. Wilkins, “Simultaneous phase and amplitude extraction from a single defocused image of a homogeneous object,” Journal of Microscopy, vol. 206, no. 1, pp. 33–40, Apr. 2002, doi: 10.1046/j.1365-2818.2002.01010.x.
[4] E. Braig et al., “Direct quantitative material decomposition employing grating-based X-ray phase-contrast CT,” Scientific Reports, vol. 8, no. 1, p. 16394, Dec. 2018, doi: 10.1038/s41598-018-34809-6.
[5] E.-M. Braig et al., “Single spectrum three-material decomposition with grating-based x-ray phase-contrast CT,” Physics in Medicine & Biology, May 2020, doi: 10.1088/1361-6560/ab9704.
Primary author
Prof.
Julia Herzen
(Biomedical Imaging Physics Physics Department & Munich School of BioEngineering Technical University of Munich)
Co-author
Dr
Madleen Busse
(Department of Physics, Technical University Munich)
