Motion correction in fMRI via registration of individual slices into an anatomical volume

TLDR

The widely used rigid‑body volume registration based on stacked slices from the time series may hinder statistical accuracy by assuming no motion between slices in multislice fMRI data. This study adapts an automated retrospective image registration based on mutual information to multislice fMRI to provide accurate motion correction. The method maps each slice to an anatomical volume acquired in the same session and evaluates registration accuracy using simulated MR data with known truth, employing mutual‑information based image registration. The mapping‑each‑slice‑to‑volume approach improves sensitivity and specificity compared with stacked‑slice correction, as demonstrated in two normal volunteers, and reliably detects consistent activation signals in a standard anatomical coordinate system. Published in Magn Reson Med 41:964–972 (1999) and © 1999 Wiley‑Liss, Inc.

Abstract

An automated retrospective image registration based on mutual information is adapted to a multislice functional magnetic resonance imaging (fMRI) acquisition protocol to provide accurate motion correction. Motion correction is performed by mapping each slice to an anatomic volume data set acquired in the same fMRI session to accommodate inter-slice head motion. Accuracy of the registration parameters was assessed by registration of simulated MR data of the known truth. The widely used rigid body volume registration approach based on stacked slices from the time series data may hinder statistical accuracy by introducing inaccurate assumptions of no motion between slices for multislice fMRI data. Improved sensitivity and specificity of the fMRI signal from mapping-each-slice-to-volume method is demonstrated in comparison with a stacked-slice correction method by examining functional data from two normal volunteers. The data presented in a standard anatomical coordinate system suggest the reliability of the mapping-each-slice-to-volume method to detect the activation signals consistent between the two subjects. Magn Reson Med 41:964–972, 1999. © 1999 Wiley-Liss, Inc.