Abstract
Nano-CT enables 3D imaging of micro/nano-structures and is becoming an indispensable tool. At such a high resolution, specimens must have a small diameter small enough to fit into the instrument’s field of view, typically a few tens of micrometers to a few hundred micrometers. As a result, samples are commonly glued to the tip of a steel pin for alignment before imaging. Ideally, data are collected from the part of a specimen above the pin and the x-ray opaque pin will not interfere with imaging. However, the tiny sample size makes precise mounting very tricky, and many times a region adjacent to the pin is found of to be of interest post mounting. Sometimes the sample is too fragile to remount and other times removing the specimen and repeating the tedious remounting steps is impractical due to time constraints, we find that the information occluded by the metal pin can be almost fully recovered via iterative reconstruction with simple metal-trace masked from a regular scan of an imperfectly mounted specimen. Specifically, combining the metal artifact reduction and interior tomography techniques, a metal trace mask in the sinogram is first extracted from a low-resolution global reconstruction which covers the whole cross-section of the pin, then the desired high-resolution reconstruction of a region of interest is iteratively reconstructed excluding any contribution from the metal trace. Our method is demonstrated with a 42.35 nm reconstruction of a portion of a sea urchin tooth, which is scanned on a synchrotron with the pin moving across the field of view during sample rotation, showing that streaking artifacts caused by pin occlusion can be greatly suppressed to achieve an image quality close to that without occlusion. These results suggest that our method has a great potential in simplifying the specimen preparation and relaxing the proficiency requirements, which significantly facilitates nano-CT imaging applications.
Original language | English (US) |
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Title of host publication | Developments in X-Ray Tomography XIV |
Editors | Bert Muller, Ge Wang |
Publisher | SPIE |
ISBN (Electronic) | 9781510654686 |
DOIs | |
State | Published - 2022 |
Event | Developments in X-Ray Tomography XIV 2022 - San Diego, United States Duration: Aug 22 2022 → Aug 24 2022 |
Publication series
Name | Proceedings of SPIE - The International Society for Optical Engineering |
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Volume | 12242 |
ISSN (Print) | 0277-786X |
ISSN (Electronic) | 1996-756X |
Conference
Conference | Developments in X-Ray Tomography XIV 2022 |
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Country/Territory | United States |
City | San Diego |
Period | 8/22/22 → 8/24/22 |
Funding
The specimen was prepared with support of grant DMR-2104759-001 to Dr. Keith Alvares, and the authors would like to thank Wenle Xu for producing the thin sections. This work made use of the MatCI Facility supported by the MRSEC program of the National Science Foundation (DMR-1720139) at the Materials Research Center of Northwestern University. Microdissection was performed on Zeiss PALM microdissection system purchased with the support of NCRR 1S10RR025624-01 at the Northwestern Center for Advanced Microscopy, supported by NCI CCSG P30 CA060553 awarded to the Robert H Lurie Comprehensive Cancer Center. This research also used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility, operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Argonne National Laboratory’s work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract DE-AC02-06CH11357.
Keywords
- Nano-CT
- interior tomography
- iterative reconstruction
- metal artifacts reduction
- pin occlusion
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering