Over the past several years, although the resolution, signal-to-noise ratio and acquisition speed of magnetic resonance imaging (MRI) technology have been increased, MR images are still affected by artifacts and noise. A tradeoff between noise reduction and the preservation of actual detail features has to be made in the way that enhances the diagnostically relevant image content. Therefore, noise reduction is still a difficult task. A variety of techniques have been presented in the literature on denoising MR images and each technique has its own assumptions, advantages and limitations. The purpose of this paper is to present a survey of the published literature in dealing with denoising methods in MR images. After a brief introduction about magnetic resonance imaging and the characteristics of noise in MRI, the popular approaches are classified into different groups and an overview of various methods is provided. The denoising method's advantages and limitations are also discussed. 
A survey on the magnetic resonance image denoising methods