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LMMSE filter for Rician MRI data

version 1.2 (3 KB) by

A filtering scheme for denoising MR data assuming an underlying Rician model.

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The linear minimum mean square error (LMMSE) estimator estimates the signal out of a noisy MR adquisition. The method automatically estimates the noise level from background. It is based on a Rician noise assumption, which is valid for single coil adquisitions (and sometimes in SENSE).

The whole method is described in

S Aja-Fernández, M. Niethammer, M. Kubicki, M. E. Shenton, C.F. Westin, "Restoration of DWI data using a Rician LMMSE estimator". IEEE Tr. on Medical Imag. Vol. 27, No. 10, Oct. 2008, pp. 1389-1403.

Comments and Ratings (8)

max Liu

I would like to know whether this method can be successfully deal with the T1 weighted MRI data

thanks

majid sadeghi

Thanks

Ram Singh

very good stuff

Christian

very useful! thank you!

The method now requires to choose one of the existing noise estimation methods as an input: (See help)

I_est=MRI_lmmse(I,[7,7],'mode2N');

However, I have just realized that the function moda.m is not in the toolbox. I upload now a new version with this fixed, and a default option

Alex

Alex (view profile)

I get the error:

I_est = MRI_lmmse(img,[10, 10]);
Undefined function or variable "sigma2".

Error in MRI_lmmse (line 137)
K1=1+(4.*sigma2^2-4.*sigma2.*Squ)./(Qua-Squ.^2);

Did I input something incorrectly?

Updates

1.2

Default method to estimate noise is added. Function moda.m was missing and it was added to the end to the file.

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