3.4 Developments in High-Resolution CT: Studying Bioregeneration by Hard X-Ray Synchrotron-Based Microtomography☆

Computed tomography, frequently called CT, with high spatial resolution up to the (sub-)micrometer range (µCT) can be considered as microscopy in three dimensions. The spatial resolution and contrast in µCT volume images is significantly increased when synchrotron light sources are applied instead of laboratory-based X-ray tubes. This fact is related to the orders of magnitude higher photon flux density available, the nearly parallel beam propagation as well as the (partial) spatial coherence of the beam at the sample position. In this chapter, synchrotron-based microtomography using hard X-rays is employed to study bioceramic-supported bone regeneration. The high contrast and excellent signal-to-noise ratio in the tomographic images are the basis to segment the data sets. Thus, volume renderings are acquired which can be considered as an extension of classical histology into three dimensions but in a widely nondestructive manner. The principles of the techniques for acquiring as well as analyzing the images are introduced and described in this chapter including a detailed review on the available literature in order to facilitate further studies by the reader. To demonstrate the potential of synchrotron-based microtomography in biomaterials research, the example of regenerating human bone tissue with the support of clinically established bone substitute materials is chosen. Furthermore, results from an animal study are shown in which various resorbable ceramics were compared for bone grafting. For the future, exploiting the coherence of the X-ray beam at a synchrotron light source for low-dose X-ray imaging bears enormous potential to study bioregenenration in vivo and in a longitudinal way .