Non-destructive phase contrast hard x-ray imaging to reveal the three-dimensional microstructure of soft and hard tissues

Abstract

X-ray imaging in the absorption contrast mode is an established method of visualising calcified tissues such as bone and teeth. Physically soft tissues such as brain or muscle are often imaged using magnetic resonance imaging (MRI). However, the spatial resolution of MRI is insufficient for identifying individual biological cells within three-dimensional tissue. X-ray grating interferometry (XGI) has advantages for the investigation of soft tissues or the simultaneous three-dimensional visualisation of soft and hard tissues. Since laboratory microtomography (µCT) systems have better accessibility than tomography set-ups at synchrotron radiation facilities, a great deal of effort has been invested in optimising XGI set-ups for conventional µCT systems. In this conference proceeding, we present how a two-grating interferometer is incorporated into a commercially available nanotom ® m (GE Sensing & Inspection Technologies GmbH) µCT system to extend its capabilities toward phase contrast.We intend to demonstrate superior contrast in spiders (Hogna radiata (Fam. Lycosidae) and Xysticus erraticus (Fam. Thomisidae)), as well as the simultaneous visualisation of hard and soft tissues. XGI is an imaging modality that provides quantitative data, and visualisation is an important part of biomimetics; consequently, hard X-ray imaging provides a sound basis for bioinspiration, bioreplication and biomimetics and allows for the quantitative comparison of biofabricated products with their natural counterparts.

Implementation of a double-grating interferometer for phase-contrast computed tomography in a conventional system nanotom® m

“…A double-grating symmetric interferometric set-up, 28 see Fig. 1, was incorporated into the advanced lCT system nanotom V R m with an adjustable focal spot diameter w (0.9-2.7 lm).…”

“…40 A double-grating symmetric interferometric set-up was incorporated into the lCT system nanotom V R m. The measurements were performed using a phase grating G1 with a periodicity of 7 lm and a gold structure height of 6 lm, in order to induce a phase shift of p for the photon energy of 30 keV, corresponding to an estimated acceleration voltage of 42 kVp. 28 The gold lines of an analyzer grating G2 had a structure height of 85 lm with a periodicity of 7 lm. The inter-grating distance corresponds to the first fractional Talbot order, where the phase grating G1 is positioned at a distance of d 1 ¼ 29.6 cm downstream from the source and the analyzer grating just in front of the detector d 2 ¼ 29.6 cm.…”

Histology-validated x-ray tomography for imaging human coronary arteries

“…Moreover, histology belongs to the destructive analysis methods. In order to overcome these difficulties, non-destructive three dimensional (3D) X-ray imaging, such as micro computed tomography (µCT), is promising alternative for the characterization of atherosclerotic coronary arteries [5,6,[8][9][10]. One of the problems of X-ray tomography in absorption mode is the simultaneous visualization of soft and highly absorbing tissues: If the photon energy is optimized for the visualization of highly absorbing tissues, the soft tissues are almost transparent to the X-rays and provide poor contrast.…”

Combining High-Resolution Hard X-ray Tomography and Histology for Stem Cell-Mediated Distraction Osteogenesis

“…To master the imaging challenge, we propose employing micro computed tomography (µ CT), a method that enables us to non-destructively visualize hard and soft tissues with isotropic micrometer resolution [9,10]. This approach, however, has several limitations.…”