Fig. 7.

Examples of MRI artifacts in T1 volumes present in the ABIDE dataset. a Head motion artifacts, with increasing magnitude of motion left to right. Volumes comparable to images 1 and 2 would be suitable for further analysis, but those rated as 3 through 5 have too much head motion to be useable. While most of the ABIDE data is of reasonable quality, it is large dataset and includes participants with autism spectrum disorder as well as children, both factors known to be associated with increased head motion (Pardoe et al. 2016; Engelhardt et al. 2017; Greene et al. 2018). b Ghosting artifacts, visible as overlapping images. The example on the left is only visible in the background with a constrained intensity range, but still results in distortions in the image. The image on the right shows a clear duplicate contour of the back of the head. c Blood flow artifact, creating a horizontal band of distortion, here affecting temporal lobe imaging. d Spike noise artifact, resulting in inconsistent signal intensity. e Coil failure artifact, resulting in a regional distortion around the affected coil. Participant IDs are included below each image to allow for the further examination of the original 3D volumes. Artifact MRIs were identified with the aid of MRIQC (Esteban et al. 2017). Pre-computed results are available from https://mriqc.s3.amazonaws.com/abide/T1w_group.html