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Radiation dose reduction and image enhancement in biological imaging through equally-sloped tomography

Lee, Edwin and Fahimian, Benjamin P. and Iancu, Cristina V. and Suloway, Christian and Murphy, Gavin E. and Wright, Elizabeth R. and Castaño-Díez, Daniel and Jensen, Grant J. and Miao, Jianwei (2008) Radiation dose reduction and image enhancement in biological imaging through equally-sloped tomography. Journal of Structural Biology, 164 (2). pp. 221-227. ISSN 1047-8477. PMCID PMC3099251.

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Electron tomography is currently the highest resolution imaging modality available to study the 3D structures of pleomorphic macromolecular assemblies, viruses, organelles and cells. Unfortunately, the resolution is currently limited to 3–5 nm by several factors including the dose tolerance of biological specimens and the inaccessibility of certain tilt angles. Here we report the first experimental demonstration of equally-sloped tomography (EST) to alleviate these problems. As a proof of principle, we applied EST to reconstructing frozen-hydrated keyhole limpet hemocyanin molecules from a tilt-series taken with constant slope increments. In comparison with weighted back-projection (WBP), the algebraic reconstruction technique (ART) and the simultaneous algebraic reconstruction technique (SART), EST reconstructions exhibited higher contrast, less peripheral noise, more easily detectable molecular boundaries and reduced missing wedge effects. More importantly, EST reconstructions including only two-thirds the original images appeared to have the same resolution as full WBP reconstructions, suggesting that EST can either reduce the dose required to reach a given resolution or allow higher resolutions to be achieved with a given dose. EST was also applied to reconstructing a frozen-hydrated bacterial cell from a tilt-series taken with constant angular increments. The results confirmed similar benefits when standard tilts are utilized.

Item Type:Article
Related URLs:
URLURL TypeDescription CentralArticle
Iancu, Cristina V.0000-0002-7352-9226
Jensen, Grant J.0000-0003-1556-4864
Additional Information:© 2008 Elsevier. Received 5 May 2008; revised 25 July 2008; accepted 31 July 2008. Available online 15 August 2008. We thank H. Jiang for the help with the figures. JM thanks O. Levi, W. Chiu and Z.H. Zhou for stimulating discussions. This work was supported in part by the US Department of Energy, Office of Basic Energy Sciences under the contract number DE-FG02-06ER46276, the US National Science Foundation, Division of Materials Research (DMR-0520894), UC Discovery/TomoSoft Technologies, LLC under the Contract Number IT107-10166 and the Alfred P. Sloan foundation. GJJ acknowledges funding from the NIH (R01 AI067548 and P50 GM082545), DOE (Grant DE-FG02-04ER63785), a Searle Scholar Award to GJJ, the Beckman Institute at Caltech, and gifts to Caltech from the Gordon and Betty Moore Foundation and Agouron Institute. Supplementary data associated with this article can be found, in the online version, at doi:10.1016/j.jsb.2008.07.011.
Funding AgencyGrant Number
Department of Energy (DOE)DE-FG02-06ER46276
UC Discovery/TomoSoft Technologies, LLCIT107-10166
Alfred P. Sloan FoundationUNSPECIFIED
NIHR01 AI067548
NIHP50 GM082545
Department of Energy (DOE)DE-FG02-04ER63785
Searle Scholars ProgramUNSPECIFIED
Caltech Beckman InstituteUNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
Agouron InstituteUNSPECIFIED
Subject Keywords:Equally-sloped tomography; Electron cryomicroscopy; Iterative reconstruction algorithm; Radiation dose reduction; Image enhancement; Computed tomography
Issue or Number:2
PubMed Central ID:PMC3099251
Record Number:CaltechAUTHORS:LEEjsb08
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:12667
Deposited By: Archive Administrator
Deposited On:18 Dec 2008 18:22
Last Modified:03 Oct 2019 00:30

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