Berlin 2015 – scientific programme

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BP: Fachverband Biologische Physik

BP 1: Imaging

BP 1.12: Talk

Monday, March 16, 2015, 12:45–13:00, H 1028

Propagation-based phase contrast tomography of neuronal tissues — •Mareike Töpperwien¹, Martin Krenkel¹, Jürgen Goldschmidt², and Tim Salditt¹ — ¹Institute for X-Ray Physics, Göttingen, Germany — ²Leibniz Institute for Neurobiology, Magdeburg, Germany

In order to visualize the 3D native structure of neuronal tissues with cellular and sub-cellular resolution in macroscopically large volumes, hard x-ray tomography offers a unique potential beyond the current capabilities of histology. However, classical x-ray tomography based on absorption gives nearly no contrast for soft biological tissues. In order to visualize also non-absorbing or weakly absorbing structures, the much stronger phase shifts which the sample induces in a (partially) coherent wavefront can be exploited for contrast formation. During free space propagation behind the object, these phase shifts are converted to a measurable intensity image by interference of the disturbed wave fronts. Thus, the original phase distribution has to be reconstructed from the intensity images using suitable phase retrieval algorithms.

As proof-of-concept, in this work we present propagation-based x-ray phase contrast tomography of neuronal tissues. In specially dried samples, sub-cellular resolution in mm sized tissue volumes has been achieved yielding three dimensional renderings which are consistent with classical histology results. We also show that complementing the synchrotron radiation results, a compact laboratory setup with a high brilliance liquid-metal microfocus source can be used.