Table I.
Demographic characteristics and global brain tissue parameters of the professional ballet dancers and the control females
| Variable | Professional ballet dancers | Control subjects | Probability two‐tailed | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Mean | S.D. | Min. | Max. | Mean | S.D. | Min. | Max. | ||
| Age (years) | 21.9 | 3.03 | 18.3 | 27.8 | 24.8 | 5.50 | 18.5 | 37.8 | P = 0.17 |
| Body‐mass index (BMI) | 18.7 | 1.53 | 16.7 | 21.9 | 21.6 | 2.32 | 18.6 | 25.8 | P = 0.003 |
| Education (years) | 11.1 | 1.83 | 9.0 | 13.0 | 14.3 | 2.56 | 12.0 | 22.5 | P = 0.01 |
| Age of dance commencement | 7.3 | 2.50 | 4.0 | 13.0 | — | — | — | — | — |
| Intensity of training (h/week) | 35.8 | 7.83 | 20.0 | 45.0 | — | — | — | — | — |
| Total GM volume (cm3) | 717.5 | 81.21 | 625.5 | 844.8 | 753.9 | 55.65 | 661.4 | 851.7 | P = 0.26 |
| Total WM volume (cm3) | 405.0 | 48.89 | 338.5 | 488.4 | 432.7 | 22.97 | 390.7 | 462.8 | P = 0.13 |
| Total CSF volume (cm3) | 434.6 | 76.58 | 377.5 | 568.1 | 457.0 | 23.99 | 413.1 | 484.3 | P = 0.44 |
| Total IC volume (cm3) | 1566.3 | 152.66 | 1318.1 | 1741.6 | 1639.1 | 77.19 | 1558.0 | 1764.2 | P = 0.24 |
| Mean fractional anisotropy | 0.141 | 0.0041 | 0.130 | 0.145 | 0.144 | 0.0050 | 0.138 | 0.156 | P = 0.08 |
| Average mean diffusivity (mm2/s) | 0.000917 | 0.000026 | −0.0042 | 0.0046 | 0.000916 | 0.000029 | −0.0041 | 0.0046 | P = 0.92 |
There were significant differences in body‐mass index and years of education as well as a trend toward significance (0.05 < P < 0.1) in mean fractional anisotropy between the groups revealed by t‐tests for independent samples. Note that the minima of average mean diffusivity are negative because the tool used to compute these values does not impose that the tensors are positive.
CSF, cerebrospinal fluid; GM, gray matter; IC, intracranial; Max., maximum; Min., minimum; S.D., standard deviation; WM, white matter.