Figure 1.

Correlation coefficients for subjects 1 (left) and 2 (right). The coefficients were calculated for correlation between motion parameters recorded by the prospective motion correction system and those estimated by retrospective motion correction from different software packages. Each bar is the average across 3 coefficients, that is, for translational motion parameters (left group) and rotational (right group), 2 scans, and 2 resolutions. Different colors correspond to different software packages used for motion realignment, with FSL 1 and 2 being FSL package using the default normalized mutual information and least squares methods, respectively.