Selective channel combination of MRI signal phase

Vegh, Viktor, O'Brien, Kieran, Barth, Markus and Reutens, David C. (2015) Selective channel combination of MRI signal phase. Magnetic Resonance in Medicine, . doi:10.1002/mrm.26057

Author Vegh, Viktor
O'Brien, Kieran
Barth, Markus
Reutens, David C.
Title Selective channel combination of MRI signal phase
Journal name Magnetic Resonance in Medicine   Check publisher's open access policy
ISSN 0740-3194
Publication date 2015-11-24
Year available 2015
Sub-type Article (original research)
DOI 10.1002/mrm.26057
Open Access Status Not Open Access
Total pages 9
Place of publication Hoboken, NJ, United States
Publisher John Wiley & Sons
Collection year 2015
Language eng
Formatted abstract
Purpose:  Signal magnitude can robustly be combined using the sum-of-squares approach. Methods have been developed to combine complex images. However, techniques based only on signal phase have not been developed and evaluated.

Theory and Methods:  We performed simulations to demonstrate the effect of noise on coil combination. 32-channel 7 Tesla human gradient echo MRI brain data were collected. We combined phase images based on phase noise leading to spatially selective and coil selective combination of phase images. We compared our selective combination approach to optimal noise distribution and adaptive combination methods.

Results:  We found that selective combination of signal phases leads to improved phase signal-to-noise ratio. Furthermore, a phase shift can be present in combined phase images introduced by the method used to combine multiple channel phases.

Conclusion:  Mapping of signal phase from ultra-high field MRI data undoubtedly provides a wealth of information about the ageing brain and the effects of neurodegenerative disorders. Measurement of signal phase is essential in frequency shift mapping and in quantitative susceptibility mapping. The method used to combine signal phase should be informed by an understanding of the noise distribution in signal phase at the individual channel level. 
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
Centre for Advanced Imaging Publications
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Created: Thu, 04 Feb 2016, 16:12:51 EST by Lorine Wilkinson on behalf of Centre for Advanced Imaging