| Popis: |
On-going, large-scale neuroimaging initiatives have produced many MRI datasets with hundreds, even thousands, of individual participants and scans. These databases can aid in uncovering neurobiological causes and correlates of poor mental health, disease pathology, and many other important factors. While volumetric quantification of brain structures can be completed by expert hand-tracing, automated segmentations are becoming the only truly tractable approach for particularly large datasets. Here, we assessed the spatial and numerical reliability for newly-deployed automated segmentation of hippocampal subfields and amygdala nuclei in FreeSurfer (v7.1.0). In a sample of participants with repeated structural imaging scans (N=118), we found numerical reliability (as assessed by intraclass correlations, ICC) was reasonable, with an average ICCs of 0.853 for hippocampal subfields, and 0.878 for amygdala subnuclei. However, only 26% of all subfields and subnuclei were "excellent" in terms of having numerical reliability > 0.90. Spatial reliability was similarly reasonable, with 39% of hippocampal subfields and 33% of amygdala subnuclei having Dice coefficients > 0.70. However, and of note, multiple regions (e.g., portions of the Dentate Gyrus; Cornu Ammonis 3; Medial and Paralaminar amygdala nuclei) had poor numerical and/or spatial reliability. We also examined correlations between spatial reliability and person-level factors (e.g., participant age and sex; inter-scan interval, and difference in image quality). For these factors, inter-scan interval and sex were related to variations in spatial reliability metrics. Examined collectively, our work suggests caution should be exercised for a few hippocampal subfields and amygdala nuclei with more variable reliability. |
