A Unified Variational Approach to Denoising and Bias Correction in MR

Citation:

Fan A, Wells III WM, Fisher JW, Cetin M, Haker S, Mulkern R, Tempany CM, Willsky AS. A Unified Variational Approach to Denoising and Bias Correction in MR. Inf Process Med Imaging. 2003;18 :148-59.

Date Published:

2003 Jul

Abstract:

We propose a novel bias correction method for magnetic resonance (MR) imaging that uses complementary body coil and surface coil images. The former are spatially homogeneous but have low signal intensity; the latter provide excellent signal response but have large bias fields. We present a variational framework where we optimize an energy functional to estimate the bias field and the underlying image using both observed images. The energy functional contains smoothness-enforcing regularization for both the image and the bias field. We present extensions of our basic framework to a variety of imaging protocols. We solve the optimization problem using a computationally efficient numerical algorithm based on coordinate descent, preconditioned conjugate gradient, half-quadratic regularization, and multigrid techniques. We show qualitative and quantitative results demonstrating the effectiveness of the proposed method in producing debiased and denoised MR images.

Last updated on 05/04/2017