A Splitting Bregman-Based Compressed Sensing Approach for Radial UTE MRI

A splitting Bregman-based compressed-sensing (CS) approach (CS-SplitBerg), using the nonuniform fast Fourier transform, is proposed to reconstruct radial magnetic resonance (MR) images from undersampled k- space measurements. Using the splitting Bregman framework, the proposed CS-SplitBerg approach takes fully into account the measurement noise and exploits the combined sparsity of MR images, i.e., ℓ
₁
- norm and total variation regularization. With convergence guaranteed, the CS-SplitBerg approach uses the Bregman update process and some auxiliary variables to relax the constrained optimization problem to a sequence of easily solved unconstrained minimization problems. Experimental results using both a phantom example and a mouse cardiac example demonstrate that, under different undersampling rates, the CS-SplitBerg approach performs better than the CS-CG approach, which was introduced in our previous work. With an affordable computational cost by considering the influences of noise, the CS-SplitBerg approach can further reduce the necessary number of MR imaging (MRI) measurements for the recovery and better differentiate true MRI images from noisy data.