3D Image Reconstruction of a Fossil Using Neutron Tomography

Benjamin, Isaac; Clarke, Scarlett

Student Work

3D Image Reconstruction of a Fossil Using Neutron Tomography

Public Deposited

Non-Destructive Testing (NDT) is an interdisciplinary field encompassing various inspection techniques and principles not compromising the structural integrity of the tested objects. NDT is commonly used in medicine, mechanical engineering, materials science, and numerous applications. Neutron imaging is a very efficient tool of NDT: contrary to X-rays, neutrons, when passing through the sample, are attenuated in accordance with the sample's composition or geometrical form and produce contrasts made by light materials (e.g., hydrogen, carbon, lithium). This characteristic gives neutron imaging a particular advantage when it comes to 3D visualizations. Neutron computed tomography (NCT) found its use in visualizing the inner structure of industrial, biological, geological, engineering, and other samples of interest. In this project, a unique small fossil appearing as the vertebral column of an unknown pre-historic animal embedded in sandstone was investigated with the use of NCT. The fossil was found in the Morrison formation in Wyoming by the expedition of the Swiss Aathal Dinosaur Museum. The work in 3D image reconstruction was performed at the Swiss spallation source SINQ of the Paul Scherrer Institute (PSI) (Villigen, Switzerland). The fossils was exposed to a neutron beam, and the contrasts thus obtained were post-processed with the use of mathematical methods assuming the exponential law of radiation attenuation (the Beer–Lambert law) and using the Radon transform of the distribution of the linear neutron attenuation. Implementations of these methods in the three pieces of software, ImageJ, MuhRec, and Avizo, were used for visualization of the fossil. A high-resolution 3D image of the sandstone block with the embedded vertebral column of the unknown animal was successfully obtained. The image seems to be showing all parts of bones and ribs hidden inside the sandstone block. However, the initial analysis was inconclusive as it was not possible to identify, based on the visible set of bones, the animal behind this fossil. The image, along with the materials documenting the full process of visualization, was passed to the Aathal Dinosaur Museum for more detailed investigation with the help of external paleontologist with relevant expertise.

This report represents the work of one or more WPI undergraduate students submitted to the faculty as evidence of completion of a degree requirement. WPI routinely publishes these reports on its website without editorial or peer review.

Creator

Publisher