Super-sampling SART with ordered subsets.
In: Journal of Structural Biology, Jg. 188 (2014-11-01), Heft 2, S. 107-115
academicJournal
Zugriff:
In tomography, the quality of the reconstruction is essential because the complete cascade of the subsequent analysis is based on it. To date, weighted back-projection (WBP) has been the most commonly used technique due to its versatility and performance in sub-tomogram averaging. Here we present super-sampling SART that is based on the simultaneous algebraic reconstruction technique. While algebraic reconstruction techniques typically produce better contrast and lately showed a significant improvement in terms of processing speed, sub-tomogram averages derived from those reconstructions were inferior in resolution compared to those derived from WBP data. Super-sampling SART, however, outperforms both in term of contrast and the resolution achieved in sub-tomogram averaging several other tested methods and in particular WBP. The main feature of super-sampling SART, as the name implies, is the super-sampling option – by which parameter-based up-sampling and down-sampling are used to reduce artifacts. In particular, the aliasing that is omnipresent in the reconstruction can be practically eliminated without a significant increase in the computational time. Furthermore, super-sampling SART reaches convergence within a single iteration, making the processing time comparable to WBP, and eliminating the ambiguity of parameter-controlled convergence times. We find that grouping of projections increases the contrast, while when projections are used individually the resolution can be maximized. Using sub-tomogram averaging of ribosomes as a test case, we show that super-sampling SART achieves equal or better sub-tomogram averaging results than WBP, which is of particular importance in cryo-electron tomography. [ABSTRACT FROM AUTHOR]
Titel: |
Super-sampling SART with ordered subsets.
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Autor/in / Beteiligte Person: | Kunz, Michael ; Frangakis, Achilleas S. |
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Zeitschrift: | Journal of Structural Biology, Jg. 188 (2014-11-01), Heft 2, S. 107-115 |
Veröffentlichung: | 2014 |
Medientyp: | academicJournal |
ISSN: | 1047-8477 (print) |
DOI: | 10.1016/j.jsb.2014.09.010 |
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