Motion artifacts in MRI: A complex problem with many partial solutions

Abstract

Subject motion during magnetic resonance imaging (MRI) has been problematic since its introduction as a clinical imaging modality. While sensitivity to particle motion or blood flow can be used to provide useful image contrast, bulk motion presents a considerable problem in the majority of clinical applications. It is one of the most frequent sources of artefacts. Over 30 years of research have produced numerous methods to mitigate or correct for motion artefacts, but no single method can be applied in all imaging situations. Instead, a ‘toolbox’ of methods exists, where each tool is suitable for some tasks, but not for others. This article reviews the origins of motion artefacts and presents current mitigation and correction methods. In some imaging situations, the currently available motion correction tools are highly effective; in other cases, appropriate tools still need to be developed. It seems likely that this multifaceted approach will be what eventually solves the motion sensitivity problem in MRI, rather than a single solution that is effective in all situations. This review places a strong emphasis on explaining the physics behind the occurrence of such artefacts, with the aim of aiding artefact detection and mitigation in particular clinical situations.

Synthetic MRI for Clinical Neuroimaging: Results of the Magnetic Resonance Image Compilation (MAGiC) Prospective, Multicenter, Multireader Trial

“…Reports have, however, shown that single scans of short duration have lower incidences of motion than longer scans. 13,26 The trial results support the use of synthetic MR imaging in brain imaging to reduce scan time and the associated discomfort for patients undergoing brain MR imaging, with diagnostic performance similar to that of conventional imaging.…”

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

“…The influence of motion on MRI neuroimaging studies, particularly high-resolution, 3D-encoded imaging where scan times can extend to several minutes, has long been recognized in both clinical and research environments (Maclaren et al, 2013, Zaitsev et al (2015)). In both settings, images that are qualitatively considered to be motion-degraded are often discarded and rescanned.…”

Sensitivity Encoding for Aligned Multishot Magnetic Resonance Reconstruction

“…In this paper we propose a general framework for rigid motion corrected reconstructions in volumetric MR acquisitions, which admits a simpler formulation than in multislice counterparts, where treatment of through-plane motion appears more intricate [4]. The contributions of our proposal are threefold: (1) we provide a fully data-based generalized reconstruction formulation where a common functional is used to estimate the rigid motion and the structural data in parallel MR using the sensitivity encoding (SENSE) redundancy the coil array provides, (2) we make use of a rigid transformation representation that fully preserves the image resolution, thereby allowing for optimal reconstructions when neglecting the non-rigid motion components 1 , and (3) we study the regime in which these fully rigidly corrected reconstructions are possible in terms of the amount of motion, encoding trajectories, number of shots and use of prior information.…”

“…From the vast literature on motion compensation in MR (see [4] for a review), we restrict ourselves to retrospective rigid motion correction methods in structural multishot MR. In [5], inconsistencies in k-space are detected by using parallel reconstruction of k-space subsets and corrupted lines are removed in order to perform the final reconstruction.…”