## 4 Results
Among such changes were myelination deficiency (\(n\) = 19; 26.8%; 95% CI [21.55-32.05]), congenital dilatation of the ventricular system (\(n\) = 9; 12.7%; 95% CI [8.75-16.65]), cortical atrophy with various locations and degrees (\(n\) = 10; 14.1%; 95% CI [9.97-18.23]), dilatation of the subarachnoid spaces (\(n\) = 7; 9.9%; \begin{table}
\begin{tabular}{l c c c} \hline \hline \multirow{2}{*}{**Imaging Changes**} & \multicolumn{3}{c}{**Acute IS**} \\ \cline{2-3}  & **Abs.** & **P, \%** & **\#195\%** \\ \hline Acute millimeter ischemic lesions (0.5 \(\times\) 1.0 cm) & 4 & 5.6 & 2.86–8.34 \\ \hline Small acute ischemic lesions (1.0 \(\times\) 3.0 cm) & 18 & 25.4 & 20.24–30.56 \\ \hline Medium-sized ischemic lesions (3 \(\times\) 5.0 cm) & 37 & 52.1 & 46.17–58.03 \\ \hline Large ischemic lesions (encephalomalacia or porenephaly) & 8 & 11.3 & 7.55–15.05 \\ \hline Large ischemic lesions with diffuse & & & \\encephalomalacia and ischemic & 4 & 5.6 & 2.86–8.34 \\ destructive-necrotic lesions & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Changes detected in brain MRI examination during the acute period of IS in neonates (abs., %). \begin{table}
\begin{tabular}{l c c c} \hline \hline \multirow{2}{*}{**Imaging Changes**} & \multicolumn{3}{c}{**Acute IS**} \\ \cline{2-3}  & **Abs.** & **P, \%** & **\#195\%** \\ \hline Acute millimeter ischemic lesions (0.5 \(\times\) 1.0 cm) & 1 & 2.7 & 0.03–5.37 \\ \hline Small acute ischemic lesions (1.0 \(\times\) 3.0 cm) & 8 & 21.6 & 14.83–28.37 \\ \hline Medium-sized ischemic lesions (3 \(\times\) 5.0 cm) & 17 & 46 & 37.71–54.09 \\ \hline Large ischemic lesions (encephalomalacia or porenephaly) & 7 & 18.9 & 12.46–25.34 \\ \hline Large ischemic lesions with diffuse & & & \\ encephalomalacia and ischemic & 4 & 10.8 & 5.7–15.9 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Changes detected during brain MRI examination during the acute period of IS in children aged 28 days–18 years (abs., %). 95% CI [6.36-13.44]), nonspecific glioependymal foci (\(n=6\); 8.5%; 95% CI [5.2-11.8]), nonspecific intracerebral foci with subcortical extension (\(n=5\); 7.0%; 95% CI [3.96-10.04]), intracerebral cystic formations (\(n=3\); 4.2%; 95% CI [1.81-6.59]), etc. (Figure 4). Such changes, in some cases combined, were mainly detected in the group of infants and young children. In some children, besides ischemic foci, other types of changes were observed, which might have been present before the stroke or contributed to its onset. These included: myelination deficiency (\(n=5\); 13.5%; 95% CI [7.88-19.12]), ventricular system dilatation (\(n=9\); 24.3%; 95% CI [17.25-31.35]), cortical atrophy of varying degrees and locations (\(n=6\); 16.2%; 95% CI [10.14-22.26]), subarachnoid space dilatation (\(n=5\); 13.5%; 95% CI [7.88-19.12]), nonspecific glioependymal foci of various sizes (\(n=7\); 18.9%; 95% CI [12.46-25.34]), nonspecific intracerebral foci with subcortical extension (\(n=2\); 5.4%; 95% CI [1.68-9.12]), intracerebral cystic formations (\(n=3\); 8.1%; 95% CI [3.61-12.59]), and other anomalies of brain development (Figure 5). These changes, sometimes occurring together, were predominantly observed in infants and young children. Figure 4: Other changes detected during cerebral MRI examination, associated with AVCI in newborns and children (in absolute numbers and %). _Note:_ MD—myelination deficiency, CA—cortical atrophy, CDVS—congenital dilation of the ventricular system, DSS—dilation of the subarachnoid spaces, NGEF—nonspecific glioependymal foci, IPSE—intracerebral foci with nonspecific subcortical extension, ICF—intracerebral cystic formations. Figure 3: Distribution of ischemic lesions detected during cerebral MRI examination depending on the size of the focus in newborns and children (in absolute numbers and %).