Simultaneous motion correction and T1 estimation in quantitative T1 mapping: An ML restoration approach

摘要

In magnetic resonance imaging the spin-lattice relaxation time (T) of tissues is estimated from a set of T-weighted images. As the T estimation is a voxel-wise estimation, correct alignment of the T-weighted images is crucial for T mapping. Therefore, to correct for motion, the T-weighted images are often registered prior to the T estimation. This two-step approach, however, does not provide an accurate motion detection due to the high dynamic contrast changes in the series of images. Moreover, interpolation effects during registration, propagate to the T estimation. In this work, we propose a unified approach, where the motion estimation is integrated into the T estimation procedure. The motion model parameters and T parameters are jointly estimated using a Maximum Likelihood (ML) approach. Results on simulation and real data experiments show a substantial improvement in the precision and accuracy of the estimated T map compared to the conventional two-step approach.