Overlapped k-Space Acquisition and Reconstruction Technique for Motion Artifact Reduction in Magnetic Resonance Imaging

A new MRI acquisition strategy based on acquiring the k-space in consecutive overlapped bands was developed. Starting from the general assumption of rigid body motion, we consider the case when the acquisition of the k-space is in the form of bands of finite number of lines arranged in a rectilinear fashion to cover the k-space area of interest. We consider cases with an averaging factor of at least 2. Instead of acquiring a full k-space of each image and then average the result, we developed a new acquisition strategy based on acquiring the k-space in consecutive overlapped bands. In case of no motion, this overlap can be used as the second acquisition. On the other hand, when motion is encountered, such overlap can be used to substantially reduce motion artifacts in the resultant image. This is achieved by utilizing the overlap area to estimate the motion, which is then taken into consideration in image reconstruction. We demonstrate the success of this approach using both numerical simulations as well as real data acquired from a human volunteer. The new method has the potential for practical applications to make more efficient use of MRI scanners and making the scanning time lower providing more comfort to the patient.