Prospective motion correction of high-resolution magnetic resonance imaging data in children

Abstract

Motion artifacts pose significant problems for the acquisition and analysis of high-resolution magnetic resonance imaging data. These artifacts can be particularly severe when studying pediatric populations, where greater patient movement reduces the ability to clearly view and reliably measure anatomy. In this study, we tested the effectiveness of a new prospective motion correction technique, called PROMO, as applied to making neuroanatomical measures in typically developing school-age children. This method attempts to address the problem of motion at its source by keeping the measurement coordinate system fixed with respect to the subject throughout image acquisition. The technique also performs automatic rescanning of images that were acquired during intervals of particularly severe motion. Unlike many previous techniques, this approach adjusts for both in-plane and through-plane movement, greatly reducing image artifacts without the need for additional equipment. Results show that the use of PROMO notably enhances subjective image quality, reduces errors in Freesurfer cortical surface reconstructions, and significantly improves the subcortical volumetric segmentation of brain structures. Further applications of PROMO for clinical and cognitive neuroscience are discussed.

Figure 1

T1-weighted midsagittal images by PROMO status for one subject. Reconstructed images for subject number six, comparing 3D IR-SPGR scans with PROMO off versus on, show greater image clarity and reduced blurring, ringing, and ghosting for both acquisitions using PROMO correction.

Figure 2

Segmentation results by PROMO status for one subject. Reconstructed images for subject number seven, comparing color-coded segmentation results with PROMO off versus on, show improved delineation of anatomical structures such as gray matter (color=gray), white matter (light green), caudate head (dark green), putamen (magenta), pallidum (light blue), and amygdala (aquamarine) for both acquisitions using PROMO correction.

Figure 3

Comparison of between-scan reliability for automated segmentation with and without motion correction. Percent volume overlap for structures and regions of interest with PROMO motion correction enabled and disabled. Error bars represent +/− one standard error of the mean.

Figure 4

Comparison of between-scan reliability for automated volumetric measurements with and without motion correction. Percent volume difference for structures and regions of interest with PROMO motion correction enabled and disabled. Error bars represent +/− one standard error of the mean.