In this paper we introduce a new non-uniformity correction technique for receiver dependent intensity fluctuations in NMR images. Our method was designed for lower limb images, particularly those acquired in the context of muscular dystrophy studies . The new approach was motivated by the fact that in pathological cases we cannot make assumption about the characteristics of the various tissues in the image, which is a prerequisite and a main limitation for the numerous techniques proposed in the literature. In this work we considered a parametric model for the non-uniformity field based on combination of cosine functions. The estimation of the parameters was done by minimizing a cost function that reduces the variance in the subcutaneous fat as well as the total variation of the non-uniformity function. Experimental results were promising and showed the efficiency of the proposed approach.