@article {aja2008noise, title = {Noise and signal estimation in magnitude MRI and Rician distributed images: a LMMSE approach}, journal = {Image Processing, IEEE Transactions on}, volume = {17}, number = {8}, year = {2008}, pages = {1383{\textendash}1398}, publisher = {IEEE}, author = {Santiago Aja-Fern{\'a}ndez and Carlos Alberola-Lopez and Carl-Fredik Westin} }