TABLE 1.

Demographic information of cosmonaut and control group subjects.

	Cosmonauts average (SD)	Controls average (SD)	Two-sample t-test (p-value)
Age (years)	45 (5)	43 (6)	0.349
Mission duration (days)	172 (25)
Previous mission experience (days)	199 (199)
Preflight MRI – launch (days)	89 (34)
Return – postflight MRI (days)	10 (3)
Preflight MRI – postflight MRI (days)	270 (32)	240 (54)	0.099
Return – followup MRI (days)	230 (62)

Preflight and postflight MRI for the control group represents the two scanning sessions for this group. Statistical comparisons between the two groups were performed using a two-sample t-test (2-tailed). SD = standard deviation.