Table 3.
Differences in the volume and volume ratio of the segmented regions among the three age groups
| < 40 years | 40–59 years | ≥60 years | p value | |
|---|---|---|---|---|
| Total number (female:male) | 47 (31:16) | 49 (34:15) | 37 (22:15) | |
| Intracranial space (volume, mL) | 1468.7 ± 105.7 | 1427.0 ± 141.0 | 1432.7 ± 137.5 | 0.066 |
| Total brain (mL) | 1155.5 ± 90.8 | 1096.2 ± 115.3 | 1035.8 ± 102.8 | < 0.001 |
| Cortical gray matter (mL) | 490.2 ± 33.6 | 452.7 ± 48.4 | 422.8 ± 44.1 | < 0.001 |
| Frontal cortex (mL) | 180.1 ± 13.5 | 166.7 ± 19.1 | 154.4 ± 15.8 | < 0.001 |
| Parietal cortex (mL) | 123.1 ± 9.5 | 113.5 ± 11.9 | 106.7 ± 11.4 | < 0.001 |
| Temporal cortex (mL) | 127.4 ± 9.6 | 117.5 ± 13.6 | 108.5 ± 12.6 | < 0.001 |
| Occipital cortex (mL) | 59.5 ± 6.4 | 55.0 ± 7.2 | 53.2 ± 7.0 | < 0.001 |
| Cerebral white matter (mL) | 435.1 ± 47.2 | 424.4 ± 50.2 | 387.4 ± 43.4 | < 0.001 |
| Cerebellum (mL) | 143.8 ± 13.8 | 134.2 ± 11.3 | 127.8 ± 11.4 | < 0.001 |
| Brainstem (mL) | 43.5 ± 3.6 | 42.6 ± 3.7 | 41.6 ± 3.8 | 0.166 |
| Insula cortex (mL) | 13.4 ± 1.1 | 12.7 ± 1.5 | 12.2 ± 1.5 | < 0.001 |
| Hippocampus (mL) | 6.9 ± 0.5 | 6.8 ± 0.7 | 6.8 ± 0.8 | 0.302 |
| Basal ganglia (mL) | 13.9 ± 1.4 | 13.2 ± 1.4 | 13.8 ± 1.6 | 0.035 |
| Limbic system (mL) | 35.0 ± 3.2 | 32.8 ± 3.9 | 31.6 ± 3.7 | < 0.001 |
| Total ventricle (mL) | 19.6 ± 7.5 | 21.9 ± 8.0 | 36.6 ± 14.1 | < 0.001 |
| Lateral ventricle (mL) | 17.3 ± 7.2 | 19.4 ± 7.5 | 33.4 ± 13.4 | < 0.001 |
| Third ventricle (mL) | 0.8 ± 0.3 | 0.9 ± 0.4 | 1.5 ± 0.7 | < 0.001 |
| Fourth ventricle (mL) | 1.6 ± 0.4 | 1.5 ± 0.4 | 1.7 ± 0.4 | 0.078 |
| Total subarachnoid space (mL) | 267.3 ± 35.0 | 285.7 ± 43.5 | 352.1 ± 54.3 | < 0.001 |
| Intracranial CSF space (mL) | 287.0 ± 38.3 | 307.6 ± 47.8 | 388.7 ± 63.8 | < 0.001 |
| Total ventricle on 3D T2 (mL) | 21.5 ± 7.1 | 23.7 ± 8.2 | 38.0 ± 14.1 | < 0.001 |
| Total subarachnoid space on 3D T2 (mL) | 215.2 ± 43.5 | 243.5 ± 51.9 | 305.6 ± 57.2 | < 0.001 |
| Intracranial CSF space on 3D T2 (mL) | 236.7 ± 47.0 | 267.2 ± 55.6 | 343.6 ± 64.5 | < 0.001 |
| Total brain (volume ratio, %) | 78.7 ± 2.0 | 76.8 ± 2.3 | 72.3 ± 2.6 | < 0.001 |
| Cortical gray matter (%) | 33.4 ± 1.4 | 31.7 ± 1.2 | 29.5 ± 1.1 | < 0.001 |
| Frontal cortex (%) | 12.3 ± 0.6 | 11.7 ± 0.6 | 10.8 ± 0.5 | < 0.001 |
| Parietal cortex (%) | 8.4 ± 0.5 | 8.0 ± 0.4 | 7.4 ± 0.4 | < 0.001 |
| Temporal cortex (%) | 8.7 ± 0.5 | 8.2 ± 0.4 | 7.6 ± 0.4 | < 0.001 |
| Occipital cortex (%) | 4.1 ± 0.3 | 3.9 ± 0.3 | 3.7 ± 0.3 | < 0.001 |
| Cerebral white matter (%) | 29.6 ± 1.6 | 29.7 ± 1.3 | 27.1 ± 2.1 | < 0.001 |
| Cerebellum (%) | 9.8 ± 0.7 | 9.4 ± 0.7 | 8.9 ± 0.6 | < 0.001 |
| Brainstem (%) | 3.0 ± 0.2 | 3.0 ± 0.2 | 2.9 ± 0.2 | 0.090 |
| Insula cortex (%) | 0.9 ± 0.1 | 0.89 ± 0.05 | 0.85 ± 0.06 | < 0.001 |
| Hippocampus (%) | 0.47 ± 0.03 | 0.48 ± 0.03 | 0.47 ± 0.03 | 0.376 |
| Basal ganglia (%) | 0.95 ± 0.09 | 0.92 ± 0.07 | 0.97 ± 0.08 | 0.039 |
| Limbic system (%) | 2.38 ± 0.14 | 2.3 ± 0.1 | 2.2 ± 0.1 | < 0.001 |
| Total ventricle (%) | 1.3 ± 0.5 | 1.5 ± 0.5 | 2.5 ± 0.8 | < 0.001 |
| Lateral ventricle (%) | 1.2 ± 0.5 | 1.3 ± 0.5 | 2.3 ± 0.8 | < 0.001 |
| Third ventricle (%) | 0.05 ± 0.02 | 0.06 ± 0.03 | 0.11 ± 0.04 | < 0.001 |
| Fourth ventricle (%) | 0.11 ± 0.02 | 0.11 ± 0.02 | 0.12 ± 0.02 | 0.114 |
| Intracranial CSF space (%) | 19.5 ± 2.2 | 21.5 ± 2.4 | 27.1 ± 3.0 | < 0.001 |
p-value of the differences between the three age groups based on the Kruskal–Wallis rank sum test