“…Nonlinear registration (Ashburner, 2007;Avants et al, 2008;Rueckert et al, 1999;Vercauteren et al, 2009) estimates local deformations between pairs of images, and these algorithms tend to produce more accurate estimates when they can focus entirely on the anatomy of interest (Klein et al, 2009;Ou et al, 2014). Similarly, skull-stripping increases the reliability of linear registration (Cox and Jesmanowicz, 1999;Friston et al, 1995;Hoffmann et al, 2015;Jenkinson and Smith, 2001;Jiang et al, 1995;Modat et al, 2014;Reuter et al, 2010) by excluding anatomy that deforms non-rigidly, such as the eyes, jaw, and tongue (Andrade et al, 2018;Fein et al, 2006;Fischmeister et al, 2013;Hoffmann et al, 2020).…”