Imperial College London
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Dr Peter J Lally

Faculty of Engineering, Department of Bioengineering

Sir Henry Wellcome Fellow and Proleptic Lecturer
 
 
 
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Contact

 

p.lally

 
 
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Location

 

511ASir Michael Uren HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Lally:2021:10.1002/mrm.28593,
author = {Lally, P and Matthews, P and Bangerter, N},
doi = {10.1002/mrm.28593},
journal = {Magnetic Resonance in Medicine},
pages = {2477--2489},
title = {Unbalanced SSFP for super-resolution in MRI},
url = {http://dx.doi.org/10.1002/mrm.28593},
volume = {85},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Purpose: To achieve rapid, low SAR super-resolution imaging by exploiting the characteristic magnetization off-resonance profile in SSFP.Theory and Methods: In the presented technique, low flip angle unbalanced SSFP imaging is used to acquire a series of images at a low nominal resolution which are then combined in a super-resolution strategy analogous to non-linear structured illumination microscopy. This is demonstrated in principle via Bloch simulations and synthetic phantoms, and the performance is quantified in terms of point-spread function (PSF) and signal-to-noise ratio (SNR) for gray and white matter from field strengths of 0.35T to 9.4T. A k-space reconstruction approach is proposed to account for B0 effects. This was applied to reconstruct super-resolution images from a test object at 9.4T.Results: Artifact-free super-resolution images were produced after incorporating sufficient preparation time for the magnetization to approach the steady state. High-resolution images of a test object were obtained at 9.4T, in the presence of considerable B0 inhomogeneity. For gray matter, the highest achievable resolution ranges from 3% of the acquired voxel dimension at 0.35T, to 9% at 9.4T. For white matter, this corresponds to 3% and 10% respectively. Compared to an equivalent segmented gradient echo acquisition at the optimal flip angle, with a fixed TR of 8ms, gray matter has up to 34% of the SNR at 9.4T while using a x10 smaller flip angle. For white matter, this corresponds to 29% with a x11 smaller flip angle.Conclusion: This approach achieves high degrees of super-resolution enhancement with minimal RF power requirements.
AU  - Lally,P
AU  - Matthews,P
AU  - Bangerter,N
DO  - 10.1002/mrm.28593
EP  - 2489
PY  - 2021///
SN  - 0740-3194
SP  - 2477
TI  - Unbalanced SSFP for super-resolution in MRI
T2  - Magnetic Resonance in Medicine
UR  - http://dx.doi.org/10.1002/mrm.28593
UR  - https://onlinelibrary.wiley.com/doi/10.1002/mrm.28593
UR  - http://hdl.handle.net/10044/1/84896
VL  - 85
ER  -
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