TABLE 1.
Differences in hippocampal subfield volumes in older adults, patients with MCI and patients with AD using automatic FreeSurfer 6.0 segmentation of T1‐weighted MRI and manual segmentation of proton density (PD)‐weighted MRI. Bold font indicates significance after Bonferroni correction (0.05/24)
| Older adults vs. MCI | Older adults vs. AD | MCI vs. AD | ||||
|---|---|---|---|---|---|---|
| FS6‐T1 | Effect size (95% CI) | p‐value | Effect size (95% CI) | p‐value | Effect size (95% CI) | p‐value |
| CA1 | 1.19 (0.28; 2.10) | .02 | 2.35 (1.49; 3.21) | 0.000000001 | 0.97 (0.07; 2.00) | .01 |
| CA2/3/4/DG a | 1.59 (0.65; 2.53) | .001 | 2.08 (1.16; 2.91) | 0.00000007 | 0.45 (0.54; 1.45) | .25 |
| SUB b | 1.11 (0.21; 2.01) | .03 | 2.78 (1.86; 3.70) | 0.00000000003 | 1.56 (0.44; 2.67) | 0.0006 |
| Whole hippocampus | 1.56 (0.62; 2.50) | .002 | 2.70 (1.79; 3.61) c | 0.00000000004 | 0.93 (0.10; 1.96) | .01 |
| Man‐PD | ||||||
| CA1 | 1.47 (0.54; 2.40) | 0.0001 | 1.62 (0.83; 2.39) | 0.00000008 | 0.04 (0.94; 1.03) | .69 |
| CA2/3/4/DG | 0.19 (−0.67; 1.05) | .93 | 1.03 (0.32; 1.75) | 0.023 | 0.65 (0.36; 1.65) | .21 |
| SUB | 1.00 (0.11; 1.89) | .06 | 1.81 (1.02; 2.60) | 0.000002 | 0.63 (0.38; 1.64) | .09 |
| Whole hippocampus | 1.08 (0.18; 1.98) | .02 | 1.98 (1.17; 2.80) | 0.0000003 | 0.45 (0.46; 1.54) | .11 |
Abbreviations: AD, Alzheimer's disease; CA, cornu ammonis; CI, confidence interval; DG, dentate gyrus; Man, manual; MCI, Mild Cognitive Impairment; PD, proton density; SUB, subiculum.
This label includes CA2, CA3, CA4 and GC‐DG.
This label includes subiculum, presubiculum and parasubiculum.
cThe slightly higher reported effect sizes are likely due to a previously reported bias in FreeSurfer 6.0 where larger hippocampal volumes are over‐segmented to a larger extent than smaller hippocampal volumes (Schmidt et al., 2018), which could potentially explain the larger effect size in the current study.