Table 2.
Brain tissue growth in VPT infants before and after 33–34 weeks’ gestation
| Absolute Tissue Growth (cm3/week) | ||||
|---|---|---|---|---|
| Tissue Type | Delta | Mean (SD) (n=9) | Mean Difference (95% CI) | P-value |
| Total Tissue | 1 2 |
15.59 (3.63) 20.56 (2.25) |
4.98 (2.51, 7.45) | .002 |
| CSF | 1 2 |
8.60 (8.17) 5.55 (2.87) |
−3.05 (−9.08, 2.97) | .276 |
| Unmyelinated WM | 1 2 |
6.69 (2.26) 5.10 (0.91) |
−1.60 (−3.55, 0.36) | .096 |
| Myelinated WM | 1 2 |
0.21 (0.07) 0.28 (0.12) |
0.07 (−0.04, 0.17) | .174 |
| Cortical GM | 1 2 |
6.27 (1.43) 11.88 (2.26) |
5.61 (3.56, 7.66) | .0002 |
| DNGM | 1 2 |
1.38 (1.51) 1.10 (0.31) |
−0.28 (−1.40, 0.85) | .584 |
| Cerebellum | 1 2 |
1.20 (0.27) 1.55 (0.37) |
0.35 (0.13, 0.57) | .006 |
| ICV | 1 2 |
21.75 (4.00) 25.46 (5.40) |
3.71 (0.55, 6.86) | .027 |
| Relative Tissue Growth (%/week) | ||||
| Tissue Type | Delta | Mean (SD) (n=9) | Mean Difference (95% CI) | P-value |
| Unmyelinated WM | 1 2 |
−0.62 (0.48) −1.64 (0.59) |
−1.02 (−1.77, −0.27) | .014 |
| Myelinated WM | 1 2 |
−0.08 (0.03) −0.04 (0.05) |
0.03 (−0.01, 0.07) | .105 |
| Cortical GM | 1 2 |
0.52 (0.49) 1.62 (0.58) |
1.10 (0.35, 1.85) | .010 |
| DNGM | 1 2 |
0.18 (0.87) −0.10 (0.08) |
−0.28 (−0.96, 0.40) | .377 |
| Cerebellum | 1 2 |
0.28 (0.09) 0.16 (0.08) |
−0.11 (−0.19, −0.03) | .013 |
Delta 1: ≤33–34 weeks; Delta 2: ≥33–34 weeks
VPT=very preterm; SD=standard deviation; CI=confidence interval; CSF=cerebrospinal fluid; WM=white matter; GM=grey matter; DNGM=deep nuclear grey matter; ICV=intracranial volume