NOMIS: Quantifying morphometric deviation from normality over the lifetime in the adult human brain

We present NOMIS (https://github.com/medicslab/NOMIS), a comprehensive open MRI tool to assess morphometric deviation from normality in the adult human brain. Based on MR anatomical images from 6,909 cognitively healthy individuals aged 18-100 years, we modeled 1,344 measures computed using the open access FreeSurfer pipeline, taking into account personal characteristics (age, sex, head size), scanner characteristics (manufacturer and magnetic field strength), and image quality, providing expected values for any new individual. Then, for each measure, the NOMIS tool was built to generate Z-score effect sizes denoting the extent of deviation from the normative sample. Depending on the user need, NOMIS offers four versions of Z-score adjusted on different sets of variables. While all versions take into account head size, image quality and scanner characteristics, they can also incorporate age and/or sex, thereby facilitating multi-site neuromorphometric research across adulthood.