High temporal resolution retrospective motion correction with radial parallel imaging

A method for motion correction in multicoil imaging applications, involving both data collection and reconstruction, is presented. A bit‐reversed radial acquisition scheme, in conjunction with a rapid self‐calibrated parallel imaging method, Generalized auto‐calibrating partial parallel acquisition (GRAPPA) operator for wider radial bands (GROWL), is used to achieve motion correction at a high temporal resolution. View‐by‐view in‐plane motion correction is achieved in 2D imaging, while 3D motion correction is achieved for every two consecutive slice‐encoding planes in 3D imaging. In the proposed technique, GROWL contributes in two aspects: First, a central k‐space circle/cylinder used as the motion‐free reference is generated from a small number of radial lines/planes; Second, undersampled k‐space regions resulting from rotation and inconsistent (e.g. intraview and nonrigid body) motion can be filled in. When compared with navigator‐based motion correction methods, the proposed method does not prolong scan time and can be applied to short‐TR sequences. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.