Alignment of cryo-electron tomography images using Markov Random Fields

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Abstract/Contents

Abstract
Cryo-Electron tomography (CET) is the only imaging technology capable of visualizing the 3D organization of intact bacterial whole cells at nanometer resolution in situ. However, quantitative image analysis of CET datasets is extremely challenging due to very low signal to noise ratio (well below 0dB), missing data and heterogeneity of biological structures. In this thesis, we present a probabilistic framework to align CET images in order to improve resolution and create structural models of different biological structures. The alignment problem of 2D and 3D CET images is cast as a Markov Random Field (MRF), where each node in the graph represents a landmark in the image. We connect pairs of nodes based on local spatial correlations and we find the "best'' correspondence between the two graphs. In this correspondence problem, the "best'' solution maximizes the probability score in the MRF. This probability is the product of singleton potentials that measure image similarity between nodes and the pairwise potentials that measure deformations between edges. Well-known approximate inference algorithms such as Loopy Belief Propagation (LBP) are used to obtain the "best'' solution. We present results in two specific applications: automatic alignment of tilt series using fiducial markers and subtomogram alignment. In the first case we present RAPTOR, which is being used in several labs to enable real high-throughput tomography. In the second case our approach is able to reach the contrast transfer function limit in low SNR samples from whole cells as well as revealing atomic resolution details invisible to the naked eye through nanogold labeling.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2010
Issuance monographic
Language English

Creators/Contributors

Associated with Amat Gil, Fernando
Associated with Stanford University, Department of Electrical Engineering
Primary advisor Horowitz, Mark (Mark Alan)
Thesis advisor Horowitz, Mark (Mark Alan)
Thesis advisor Downing, Kenneth (Kenneth H.)
Thesis advisor Koller, Daphne
Advisor Downing, Kenneth (Kenneth H.)
Advisor Koller, Daphne

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Fernando Amat Gil.
Note Submitted to the Department of Electrical Engineering.
Thesis Thesis (Ph. D.)--Stanford University, 2010.
Location electronic resource

Access conditions

Copyright
© 2010 by Fernando Amat Gil
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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