Weighted expectation maximization reconstruction algorithms with application to gated megavoltage tomography
We propose and investigate weighted expectation maximization (EM) algorithms for image reconstruction in x-ray tomography. The development of the algorithms is motivated by the respiratory-gated megavoltage tomography problem, in which the acquired asymmetric cone-beam projections are limited in num...
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| Published in: | Physics in medicine & biology Vol. 50; no. 21; p. N299 |
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| Main Authors: | , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
England
07.11.2005
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| Subjects: | |
| ISSN: | 0031-9155 |
| Online Access: | Get more information |
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| Summary: | We propose and investigate weighted expectation maximization (EM) algorithms for image reconstruction in x-ray tomography. The development of the algorithms is motivated by the respiratory-gated megavoltage tomography problem, in which the acquired asymmetric cone-beam projections are limited in number and unevenly sampled over view angle. In these cases, images reconstructed by use of the conventional EM algorithm can contain ring- and streak-like artefacts that are attributable to a combination of data inconsistencies and truncation of the projection data. By use of computer-simulated and clinical gated fan-beam megavoltage projection data, we demonstrate that the proposed weighted EM algorithms effectively mitigate such image artefacts. |
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| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 0031-9155 |
| DOI: | 10.1088/0031-9155/50/21/N02 |