Sodium MRI enables to measure tissue sodium content (TSC) non-invasively, which provides additional cellular information and can serve as biomarker e.g. for tumor imaging. Thus, sodium imaging can complement standard clinical protocols. Many clinical routine protocols include perfusion scans with proton contrast agents but the influences on sodium relaxation times and therefore quantification accuracies of TSC are unknown. Our preliminary results showed no significant changes in sodium T1 and only small reductions of T2 with clinically relevant concentrations of contrast agents. Therefore, proton contrast agents are not expected to influence the TSC quantification in UTE sodium sequences.