Prospective motion correction with volumetric navigators (vNavs) reduces the bias and variance in brain morphometry induced by subject motion

Abstract

Recent work has demonstrated that subject motion produces systematic biases in the metrics computed by widely used morphometry software packages, even when the motion is too small to produce noticeable image artefacts. In the common situation where the control population exhibits different behaviours in the scanner when compared to the experimental population, these systematic measurement biases may produce significant confounds for between-group analyses, leading to erroneous conclusions about group differences. While previous work has shown that prospective motion correction can improve perceived image quality, here we demonstrate that, in healthy subjects performing a variety of directed motions, the use of the volumetric navigator (vNav) prospective motion correction system significantly reduces the motion-induced bias and variance in morphometry.

Utility of real-time prospective motion correction (PROMO) on 3D T1-weighted imaging in automated brain structure measurements

“…Previous studies826 and our study showed that motion-correction methods improve image qualities. However, not all motion artefacts were prevented by PROMO in “side to side” and “nodding” motion scans in this study.…”

“…analysed the utility of the navigator method for prospective motion correction, a research version of the vNavs on MEMPRAGE for Siemens scanner platforms, in brain morphology analyses26. The authors measured changes in the ratio of total brain and total GM volume of motion scans with and without motion correction compared to resting scans without motion correction using several neuroimaging methods (VBM8 of SPM8, FSL Siena and FreeSurfer) and found that the navigator method for prospective motion correction reduced motion-related bias and variance in total brain and total GM volume measurements, although comparisons of GM volume measurements on resting scans with and without PROMO were not performed.…”

Adolescent Tuning of Association Cortex in Human Structural Brain Networks

“…While we have carried out stringent quality control of our structural scans and FreeSurfer reconstructions of cortical thickness (details in Supplementary Information), we cannot completely rule out potential artefactual effects of motion on our results. Thus, further analysis of structural correlation development in datasets including estimates of head motion from volumetric tracking (Tisdall et al 2012, 2016) or novel automated estimates of data quality (Shehzad et al 2015; Pizarro et al 2016; Rosen et al 2017) will be important in the future.…”

Studying neuroanatomy using MRI

“…An appealing alternative to the hardware and patient preparation involved with external tracking systems is the use of the MR scanner itself to track and remove motion effects [91][92][93] . If additional navigators are used in the sequence, they may increase scan time but are sometimes inserted in the "dead time" present in many MR sequences during which the scanner is idle while magnetization evolves (either decays or recovers).…”