Homogenization of sample absorption for the imaging of large and dense fossils with synchrotron microtomography
2013 (English)In: Nature Protocols, ISSN 1754-2189, Vol. 8, no 9, 1708-1717 p.Article in journal (Refereed) Published
Propagation phase-contrast synchrotron radiation microtomography (PPC-SR mu CT) has proved to be very successful for examining fossils. Because fossils range widely in taphonomic preservation, size, shape and density, X-ray computed tomography protocols are constantly being developed and refined. Here we present a 1-h procedure that combines a filtered high-energy polychromatic beam with long-distance PPC-SR mu CT (sample to detector: 4-16 m) and an attenuation protocol normalizing the absorption profile (tested on 13-cm-thick and 5.242 g cm(-3) locally dense samples but applicable to 20-cm-thick samples). This approach provides high-quality imaging results, which show marked improvement relative to results from images obtained without the attenuation protocol in apparent transmission, contrast and signal-to-noise ratio. The attenuation protocol involves immersing samples in a tube filled with aluminum or glass balls in association with a U-shaped aluminum profiler. This technique therefore provides access to a larger dynamic range of the detector used for tomographic reconstruction. This protocol homogenizes beam-hardening artifacts, thereby rendering it effective for use with conventional mu CT scanners.
Place, publisher, year, edition, pages
2013. Vol. 8, no 9, 1708-1717 p.
IdentifiersURN: urn:nbn:se:uu:diva-208065DOI: 10.1038/nprot.2013.098ISI: 000323768600006OAI: oai:DiVA.org:uu-208065DiVA: diva2:651082