## 3 Results
### \({}^{1}\)HMRS Spectroscopy-Soldiers vs. Control  
The mean relative concentrations of particular metabolites were compared between the study and the control group for the frontal and occipital lobes separately. Means with standard deviations and 95% confidence intervals of the relative concentrations of particular metabolites within the frontal and occipital lobes of soldiers and healthy volunteers, as well as the \(p\) values obtained for the comparison of the mean relative concentrations of metabolites between these two groups, are shown in Table 3.  
The results show that in the frontal lobes of the soldiers the ml/Cr (\(p\) = 0.005) ratio was significantly higher, while the NAA/Cr ratio was markedly lower (\(p\) = 0.001), than in  
\begin{table}
\begin{tabular}{c c c c c c} \hline \multicolumn{2}{c}{**Neurocranium**} & \multicolumn{4}{c}{**Viscerocranium**} \\ \hline
**Finding** & **\% of Soldiers** & **No. of Soldiers** & **Finding** & **\% of Soldiers** & **No. of Soldiers** \\ \hline Asymmetry of the lateral ventricles & 11.1\% & 6 & Sinusitis & 38.9\% & 21 \\ \hline Dilated perivascular spaces & 7.4\% & 4 &
\begin{tabular}{c} Paranasal sinus \\ retention cyst \\ \end{tabular} & 14.8\% & 8 \\ \hline Enlargement of the subarachnoid spaces & 7.4\% & 4 & Sinusasal polyps & 3.7\% & 2 \\ \hline Cavum septum pellucidum and & 5.6\% & 3 & & & \\ cavum vergae & 3.7\% & 2 & & & \\ \hline Pineal cyst & 3.7\% & 2 & & & \\ \hline White matter hyperintensities & 1.9\% & 1 & & \\ \hline Empty sella & 1.9\% & 1 & & \\ \hline Meningjoma & 1.9\% & 1 & & \\ \hline \end{tabular}
\end{table}
Table 2: Anatomic variations and abnormalities observed in magnetic resonance imaging examinations of the heads of soldiers.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \multicolumn{2}{c}{**Location**} & **Metabolite** & \multicolumn{2}{c}{**Soldiers**} & \multicolumn{2}{c}{**Control Group**} & \\  & & **Mean \(\pm\) SD** & **95\% CI** & **Mean \(\pm\) SD** & **95\% CI** & \(p\) Value** \\ \hline \multirow{4}{*}{**Frontal lobes**} & NAA/Cr & 1.981 \(\pm\) 0.282 & 1.905–2.058 & 2.220 \(\pm\) 0.380 & 2.107–2.333 & 0.001 \\  & Cho/Cr & 0.943 \(\pm\) 0.125 & 0.909–0.977 & 0.907 \(\pm\) 0.100 & 0.878–0.937 & 0.121 \\  & ml/Cr & 1.936 \(\pm\) 1.009 & 1.637–2.236 & 1.374 \(\pm\) 0.538 & 1.214–1.534 & 0.005 \\  & NAA/Cr & 1.959 \(\pm\) 0.232 & 1.896–2.023 & 2.108 \(\pm\) 0.287 & 2.023–2.193 & 0.005 \\
**Occipital lobes** & Cho/Cr & 0.822 \(\pm\) 0.347 & 0.727–0.917 & 0.794 \(\pm\) 0.071 & 0.773–0.815 & 0.714 \\  & ml/Cr & 0.821 \(\pm\) 0.096 & 0.795–0.848 & 0.785 \(\pm\) 0.092 & 0.758–0.812 & 0.056 \\ \hline \end{tabular}
\begin{tabular}{c c c c c} \hline \multicolumn{2}{c}{Cl—confidence interval, SD—standard deviation} & Cho—choline, Cr—creatine, ml—myoinositol, NAA—N-acetylaspartate, was significantly higher, while the NAA/Cr ratio was markedly lower (\(p\) = 0.001), than in  
\end{table}
Table 3: The comparison of mean relative concentrations of metabolites in the frontal and occipital lobes between soldiers and controls.  
the healthy group. However, the mean relative concentration of Cho/Cr was comparable for these two groups.  
With regard to the occipital lobes, the NAA/Cr ratio was also significantly lower (\(p\) = 0.005) in military personnel compared to the control group. Furthermore, borderline statistical significance was observed for the ml/Cr ratio (\(p\) = 0.056), as there was a tendency to a higher mean relative concentration of ml in the soldiers' occipital lobes, than within the control group. No notable difference in the mean relative concentration of choline was detected.  
Exemplary spectra from VOIs in the brains of a healthy control and a soldier are shown on Figure 1.