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The rician distribution of noisy mri data
Author(s) -
Gudbjartsson HáKon,
Patz Samuel
Publication year - 1995
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910340618
Subject(s) - rician fading , noise (video) , gaussian noise , magnitude (astronomy) , distribution (mathematics) , gaussian , signal to noise ratio (imaging) , intensity (physics) , signal (programming language) , nuclear magnetic resonance , computer science , physics , artificial intelligence , mathematics , algorithm , image (mathematics) , optics , mathematical analysis , decoding methods , quantum mechanics , astronomy , fading , programming language
The image intensity in magnetic resonance magnitude images in the presence of noise is shown to be governed by a Rician distribution. Low signal intensities (SNR < 2) are therefore biased due to the noise. it is shown how the underlying noise can be estimated from the images and a simple correction scheme is provided to reduce the bias. the noise characteristics in phase images are also studied and shown to be very different from those of the magnitude images. Common to both, however, is that the noise distributions are nearly Gaussian for SNR larger than two.