3D Non-Rigid Motion Modeling of the Liver from Undersampled Golden-Radial Phase Encoding (G-RPE) Acquisitions

Christian Buerger¹, Andrew Peter King¹, Tobias Schaeffter¹, Claudia Prieto¹

We propose a method to determine a 3D non-rigid motion model of the liver from a free-breathing MR acquisition. Multiple 3D near motion-free respiratory phases of an average breathing cycle are acquired by taking advantage of the recently introduced self-gated Golden-Radial Phase Encoding (G-RPE) trajectory. Non-rigid image registrations followed by time-wise motion field interpolations are applied to model the continuous deformation of the highest quality image to all other phases allowing us to predict any respiratory phase at arbitrary respiratory positions between end-exhale and end-inhale. The proposed approach was validated on 5 volunteers achieving target registration errors of 1.83mm.