Free-Breathing Abdominal MRI Water-Fat Separation Based On Radial Sampling

Fat suppression is usually required since fat tends to be an interference in clinical MRI,while it does have diagnostic value in some clinical applications like abdominal imaging.Thus water-fat separation is of high clinical interest.But it is challenging to perform abdominal water-fat separation due to the acquisition time restriction.Conventional abdominal imaging is performed under breath-hold to address the respiratory motion artifact.On the other hand,the acquisition time of water-fat separation technique is about two or three times that of routine imaging.To address this problem,this work presents a method for free-breathing abdominal MRI water-fat separation.Free-breathing abdominal imaging is achieved by using the 3D radial stack-of-stars sequence.Different from conventional image based water-fat separation,k-space based water-fat separation is used so that chemical shift artifact can be corrected.By modifying the three-point Dixon method,simultaneous R2* map is also obtained.Parallel imaging and compressed sensing are both incorporated to accelerate imaging.Phantom study demonstrates the feasibility of chemical shift artifact correction and R2* estimation.The free-breathing abdominal imaging experiments on healthy volunteers prove that uniform water-fat separation is achieved and the acquisition can be accelerated.