Regions of interest placement for DTI analyses.

<p>Representative example of ROI placements (red circles) on high-resolution T2 images (A-C, coronal orientation; D, sagittal orientation). A: thalamus, B: internal capsule (inset: corresponding MD map), C: periventricular white matter, D: cerebellar vermis</p

Blood vessel profiles.

<p>Number of blood vessel profiles with serum extravasation in the subcortical white matter (A), periventricular white matter (B) and cortical grey matter (C) in lambs that received conventional ventilation (no SI, n = 6; ■), a single 30 s sustained inflation (single SI, n = 6; ○) or 5 consecutive 3 s sustained inflations (multiple SI, n = 5; ●). Data presented as median (IQR). One animal in the multiple SI group was omitted from analysis due to poor tissue quality.</p

Cerebral oxygen delivery.

<p>Cerebral oxygen delivery in lambs receiving 5 consecutive 3 s sustained inflations (multiple SI; ●), a single 30 s sustained inflation (single SI; ○) or conventional ventilation (no SI; ■) before the onset of ventilation (BV) and with the initiation of ventilation (designated as time 0). Data are mean ± SEM. * p<0.05 single SI vs multiple SI; # p<0.05 single SI vs no SI.</p

Peak-area MRS lactate ratios.

<p>Individual peak area MRS ratios using a single voxel encompassing supratentorial deep grey matter and central WM in protectively ventilated (PROT; open circles) and injuriously ventilated (INJ; black squares) preterm lambs. LAC; lactate, Cr; creatine, NAA; N-acetylaspartate, Cho; choline. Compared to the PROT group, MRS peak-area ratios of lactate to other metabolites (Cr, NAA, Cho) were more scattered in INJ lambs.</p

Representative images of blood vessel profiles.

<p>Representative images of blood vessel profiles (indicated by arrowheads) with serum extravasation (indicated by asterisk) in the subcortical white matter of a lamb that received a single 30 s sustained inflation (single SI; A) and 5 consecutive 3 s sustained inflations (multiple SI; B). Representative images of blood vessel profiles (indicated by arrowheads) with no serum extravasation in the subcortical white matter of a lamb that received no sustained inflation (no SI; C). Scale bar represents 90μm.</p

Magnetic resonance spectroscopy.

<p>Sample 270(TE) spectra from one lamb that received injurious ventilation with a representative example of voxel placement (right). Cho; choline, Cr; creatine, NAA; N-acetylaspartate, Lac; lactate. Peak ratios were determined for Lac/Cr, Lac/NAA, Lac/Cho, NAA/Cr, NAA/Cho and Cho/Cr.</p

Physiological parameters.

<p>(A) Fraction of inspired oxygen (FiO₂) in the unoperated control (Cont; blue open squares n = 6), sham surgery (Sham; blue closed squares n = 5), injurious ventilation (INJ; red open circles n = 5), and INJ + umbilical cord occlusion (INJ+UCO; red closed circles n = 7) groups. (B) pH. (C) Partial pressure of arterial oxygen (PaO₂) and (D) carbon dioxide (PaCO₂). *<i>P</i><0.01, **<i>P</i><0.001 vs INJ+UCO.</p

Percentage of lambs found to have AD, RD, and MD in the selected WM regions of each group below the colour map threshold intensity 90% confidence interval of the Cont group.

<p>Percentage of lambs found to have AD, RD, and MD in the selected WM regions of each group below the colour map threshold intensity 90% confidence interval of the Cont group.</p

Peak dF/dT.

<p>Peak derivative of the carotid arterial blood flow pulse (peak dF/dT) in lambs receiving 5 consecutive 3 s sustained inflations (multiple SI; ●), a single 30 s sustained inflation (single SI; ○) or conventional ventilation (no SI; ■) before the onset of ventilation (BV) and with the initiation of ventilation (designated as time 0). Data are mean ± SEM. * p<0.05 single SI vs multiple SI; # p<0.05 single SI vs no SI.</p

Fetal characteristics at the time of intervention at 124 days of gestation.

<p>Fetal characteristics at the time of intervention at 124 days of gestation.</p