Freddy Odille1, Sergio Uribe2, Tobias Schaeffter2, David Atkinson1
1Centre for Medical Image Computing, University College London, London, UK; 2Division of Imaging Sciences, King's College London, London, UK
Motion compensated reconstruction for arbitrary motion is a difficult task requiring prior knowledge about motion. One way to deal with this is to constrain the time component of motion to be correlated with certain motion sensors, such as bellows, ECG, or navigators. Here we propose an extended analysis of MR-navigators, based on 1D nonrigid registration on a per-coil basis, and principal component analysis of the resulting 1D motion fields. The method allows detection of motion eigenmodes from the imaging data themselves, which are then used to constrain a motion-compensated reconstruction for free-breathing cardiac imaging, without the need for external ECG.