Conventional noise filtering schemes applied to magnitude magnetic resonanc
e (MR) images tacitly assume Gauss distributed noise. Magnitude MR data, ho
wever, are Rice distributed. Not incorporating this knowledge leads inevita
bly to biased results, in particular when applying such filters in regions
with low signal-to-noise ratio, In this work, we show how the Rice data pro
bability distribution can be incorporated so as to construct a noise filter
that is far less biased. (C) 1999 Elsevier Science Inc.