Table 1 Change in center of mass in Gx, Gy, and Gz axis and volume change from baseline for each variable

Gz shift

mean ± SD (mm)

mean  ±  SD (mm)

Comparison of change, LDSF Astronauts vs. Controls

White Matter

0.74 ± 0.28

−0.12 ± 0.07

<0.0001

Gray Matter

0.57 ± 0.34

−0.07 ± 0.04

<0.0001

Whole Brain

0.63 ± 0.32

−0.08 ± 0.05

<0.0001

Intracranial CSF

−2.14 ± 0.83

0.12 ± 0.23

<0.0001

Intracranial Blood

−0.48 ± 1.66

−0.87 ± 0.96

0.5357

Lateral Ventricle

0.31 ± 0.52

−0.01 ± 0.21

0.0858

eaCSF

−2.45 ± 0.99

0.096 ± 0.26

<0.0001

Gx shift

mean ± SD (mm)

mean ± SD (mm)

Comparison of change, LDSF Astronauts vs. Controls

White Matter

−0.15 ± 0.27

−0.002 ± 0.09

0.1132

Gray Matter

−0.16 ± 0.18

−0.08 ± 0.20

0.3764

Whole Brain

−0.16 ± 0.20

−0.05 ± 0.15

0.2052

Intracranial CSF

0.93 ± 0.60

0.23 ± 0.66

0.0294

Intracranial Blood

−0.27 ± 1.32

−0.29 ± 0.51

0.9921

Lateral Ventricle

−0.63 ± 0.77

0.02 ± 0.24

0.0168

eaCSF

1.09 ± 0.67

0.23 ± 0.71

0.0194

Gy shift

mean ± SD (mm)

mean ± SD (mm)

Comparison of change, LDSF Astronauts vs. Controls

White Matter

0.21 ± 0.60

0.035 ± 0.06

0.3404

Gray Matter

0.034 ± 0.07

0.02 ± 0.06

0.563

Whole Brain

0.022 ± 0.06

0.023 ± 0.06

0.9775

Intracranial CSF

−0.12 ± 0.17

−0.073 ± 0.13

0.5167

Intracranial Blood

0.38 ± 0.19

−0.084 ± 0.39

0.0044

Lateral Ventricle

−0.081 ± 0.26

−0.018 ± 0.13

0.5042

eaCSF

−0.14 ± 0.16

−0.079 ± 0.15

0.3951

Volume change

mean ± SD (cm³)

mean ± SD (cm³)

Comparison of change, LDSF Astronauts vs. Controls

White Matter

3.39 ± 9.46

0.25 ± 4.72

0.437

Gray Matter

5.67 ± 6.63

−1.69 ± 1.79

0.0041

Whole Brain

9.06 ± 15.05

−1.43 ± 5.82

0.0644

Intracranial CSF

−3.73 ± 5.93

3.26 ± 1.51

0.001

Intracranial Blood

−0.55 ± 0.69

−0.47 ± 0.96

0.9549

Lateral Ventricle

2.63 ± 2.18

0.04 ± 0.33

0.0086

eaCSF

−6.49 ± 6.30

3.45 ± 1.61

<0.0001