In Vivo Study of Ischemic Stroke in Mice Brain Using Sodium MRI

The purpose of this study is to use sodium magnetic resonance imaging (sodium MRI) to observe the variations in sodium signal intensity in mice brains after ischemic stroke, and to estimate the tissue sodium concentration of the ischemia area in mice brain. Experiments were performed using a 7T MRI system. Before the MRI scan (48 hours), the mice underwent middle cerebral artery occlusion (MCAO) to induce focal brain ischemia. The average signal intensity in the sodium images of mice brains showed a 2.2-fold increase. The average estimated values of the ischemia area and contralateral area in the mice brains were 106.5 mM and 49.9 mM, respectively. This study demonstrates the feasibility of sodium MRI in mice brain of ischemic stroke at 7T MRI. The signal intensity of sodium on the mice brain shows a significant increase in the ischemia area compared to the contralateral brain hemisphere. The estimated values of the sodium concentration exhibited a significant correlation with the biochemical values of the sodium concentrations.