Multi-scale X-ray phase-contrast tomography of the cochlea

The organ of Corti in the mammalian cochlea is the receptor organ for hearing, transducing sound into auditory nerve signals. In order to further extend our understanding of the underlying neurophysiology, three dimenstional (3D) imaging capabilities are required that are able to quantify the micro-anatomy of the cochlea. Due to the subtle and intricate structure of the cochlea, a non-destructive imaging method such as 3D virtual histology by propagation-based X-ray phase-contrast computed tomography (XPCT) is preferred. This thesis investigates the structure of the mammalian cochlea of different animal models and humans with XPCT. The scales covered range from mm-sized tissue segments up to small-animal heads and the human temporal bone. Experiments have been performed at dedicated imaging beamlines at synchrotron radiation facilities and at in-house laboratory µ-CT setups, exploring sample embedding and staining protocols. Datasets in this thesis include the visualisation of noise-induced hearing loss in the guinea pig, segmentation of spiral ganglion neuron nuclei and the visualization of the orientation of cochlear implants.