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A simple method for rectified noise floor suppression: Phase-corrected real data reconstruction with application to diffusion-weighted imaging.

Authors :
Prah DE
Paulson ES
Nencka AS
Schmainda KM
Source :
Magnetic resonance in medicine [Magn Reson Med] 2010 Aug; Vol. 64 (2), pp. 418-29.
Publication Year :
2010

Abstract

Diffusion-weighted MRI is an intrinsically low signal-to-noise ratio application due to the application of diffusion-weighting gradients and the consequent longer echo times. The signal-to-noise ratio worsens with increasing image resolution and diffusion imaging methods that use multiple and higher b-values. At low signal-to-noise ratios, standard magnitude reconstructed diffusion-weighted images are confounded by the existence of a rectified noise floor, producing poor estimates of diffusion metrics. Herein, we present a simple method of rectified noise floor suppression that involves phase correction of the real data. This approach was evaluated for diffusion-weighted imaging data, obtained from ethanol and water phantoms and the brain of a healthy volunteer. The parameter fits from monoexponential, biexponential, and stretched-exponential diffusion models were computed using phase-corrected real data and magnitude data. The results demonstrate that this newly developed simple approach of using phase-corrected real images acts to reduce or even suppress the confounding effects of a rectified noise floor, thereby producing more accurate estimates of diffusion parameters.

Details

Language :
English
ISSN :
1522-2594
Volume :
64
Issue :
2
Database :
MEDLINE
Journal :
Magnetic resonance in medicine
Publication Type :
Academic Journal
Accession number :
20665786
Full Text :
https://doi.org/10.1002/mrm.22407