Work

Effects of de‐facing with mri_reface on brain measurements in ethnoracially diverse cohorts

Year: 2025

Type: article

Abstract: BACKGROUND: Use of software to "de-face" research brain images has grown as advances in automated face recognition have made it increasingly possible to re-identify participants. Imaging studies of Alzheimer's Disease and related diseases have included more participants from historically underrepresented groups, but de-facing software have primarily been validated using images from mostly non-Hispanic White participants, and its performance has not been directly compared across ethnoracial groups. METHOD: From The Health and Aging Brain Study: Health Disparities (HABS-HD) study, we constructed a sample of 305 T1-weighted MRI from HABS-HD baseline visits, matched across three ethnoracial groups (non-Hispanic White (NHW, n = 104), non-Hispanic African American (AA, n = 104), Mexican American (MA, n = 97)) according to age-decade, sex, cognitive status (impaired/unimpaired), and MRI scanner model. We ran mri_reface 0.3.5 on each image, and we ran FreeSurfer 7.4.1 on each unmodified image and on each de-faced output. We then compared regional gray matter (GM) volume and cortical thickness measurements by subtracting each de-faced image measurement from the corresponding unmodified image measurement. We compared these differences between de-faced and unmodified images across the three matched groups using GLM analyses adjusted for age, sex, and cognitive status, and Bonferroni corrected. RESULT: When aggregating across all brain regions, differences in cortical thickness measures due to de-facing were significantly different between the NHW and MA groups, and between AA and MA, but not between NHW and AA (Figure 1). Differences between these group means were <0.005mm. For GM volume, differences were significant between AA and MA (magnitude < 0.2%), but not between NHW and AA or NHW and MA (Figure 2). Examining each region individually (Figure 3), cortical thickness differences were significant for only 4 regions (all with magnitudes <0.03mm), and GM volume differences were significant for only 6 regions (all with magnitudes <2%). CONCLUSION: Effects of mri_reface on FreeSurfer brain measurements were significantly different across ethnoracial groups. Our future work will optimize mri_reface to eliminate these differences. However, the magnitudes of these differences are sufficiently small that they are unlikely to have a practical effect on analyses of data using current versions.

Source: Alzheimer s & Dementia

DOI: 10.1002/alz70862_109991