High resolution X‐ray phase contrast synchrotron imaging of normal and ligation damaged rat sciatic nerves

Abstract

This study was performed to apply synchrotron radiation (SR) imaging to a neuropathologic evaluation technique after treatment of peripheral nerve blocks. A phase contrast synchrotron images of normal and ligation damaged rat sciatic nerve were obtained with an 8 KeV monochromatic beam and 20-mum thick CsI(TI) scintillation crystal. The visual image was magnified using a 20x microscope objective and captured using an analog CCD camera. Obtained images were compared with conventional light microscopic findings from the same nerve samples. By using an edge enhancement effect of phase const with SR, we could easily discriminate each nerve fiber and identify the arrangement of nerve fibers within a whole thickness (about 1 mm in diameter) of peripheral nerve without sectioning and fixation. The composite SR image of a ligation damaged rat sciatic nerve sample showed that the response to nerve injury was different on each side of the site of injury. The SR image of damaged distal lesion showed destruction of neural microarchitecture and typical extensive Wallerian degeneration of nerve fibers as clearly as histologic image. We could get very detailed morphologic data for Wallerian degeneration of nerve fibers by using the SR imaging technique. We believe that the phase contrast synchrotron imaging has great potential as an imaging tool in the bioscience and medical science.

Three-dimensional architecture of human diabetic peripheral nerves revealed by X-ray phase contrast holographic nanotomography

“…By the use of osmium tetroxide staining, by which the present specimens were originally stained for conventional morphometry 19,20,29 , it is possible to distinguish between the axon and the surrounding myelin www.nature.com/scientificreports www.nature.com/scientificreports/ sheath as well as to identify substructures of the nerve fibres, such as the nodes of Ranvier, with their paranodes and paranodal remodelling 30 , and Schmidt-Lanterman incisures 17 , with the goal to evaluate structural alterations in diabetic neuropathy. In view of the potential use of different imaging techniques, such as synchrotron based X-ray microscopy 10,11,17,18,31 and other microscopy techniques 5-9,32 , we were able in the present study with a limited number of specimens to show detailed structures, as evaluated by a qualitative assessment, of the peripheral nerve, using the biopsies from the posterior interosseous nerve in the upper extremity in one healthy human subject and in two patients with type 1 and 2 diabetes 19,20 . Structural alterations in the sural nerve in type 1 and 2 diabetes, characterized by demyelination, degeneration and regeneration events of myelinated nerve fibre with changes in fibre density 33 and with remyelination remodelling found at the paranodal region 30 , have previously been studied and also quantified by conventional light and electron microscopical techniques, which only allows limited dimensional analyses 19,21,28,34 .…”

“…A variety of techniques are used to evaluate the macro-and microstructure in health and disease or following trauma of the peripheral nerve 1 . In clinical and experimental studies, the delicate structure of peripheral nerves can be visualized at various resolutions by conventional light and electron microscopy, generating two-dimensional (2D) images of thin tissue slices [2][3][4] , by laboratory source micro-CT [5][6][7][8][9] and synchrotron X-ray phase contrast micro-CT for three-dimensional (3D) imaging [10][11][12] and via other techniques [13][14][15] . To further understand dysfunction of the peripheral nervous system, a more detailed analysis is required to visualize the cellular network and subcomponents of the nerve trunk.…”

A Brief Review of Visualization Techniques for Nerve Tissue Engineering Applications

“…Beckmann et al acquired the 3D structural images of the unstained rat trigeminal nerves using PC-µCT, and a pattern of nerve fibers can be seen in the images [84]. Kim et al used a third generation synchrotron radiation facility for the visualization of normal and damaged rat sciatic nerve without fixation and staining, and obtained the high resolution PC-µCT images [85]. The structures with small density differences, such as nerve fibers and surrounding tissues, were successfully imaged due to the attenuation of phase boundaries.…”

Are Human Peripheral Nerves Sensitive to X-Ray Imaging?

“…PCI medical applications have received increasing interest over the past few years and efforts to implement the technique as a clinical equipment [17–21], including breast cancer investigation and joint imaging [22]. Recent studies suggest that these techniques could also be applied to nerve tissue evaluation [23–26], but only few experiments were performed so far.…”