Unilateral hypoxic-ischemic injury in the neonatal rat brain evaluated by in vivo MRI - Correlation with histopathology and neuroprotection by MK-801

RATIONALE AND OBJECTIVES. MRI was used for the in vivo evaluation of unilat eral hypoxic-ischemic brain injury and the evaluation of MK-801 in the neon atal rat. METHODS. T2-weighted scans were obtained during the acute phase of HI injur y and 3 months later, Histology was performed to correlate MRI signal chang es with pathology. Finally, the effectiveness of MK-801 to limit brain inju ry was regionally assessed in vivo using T2-weighted MRI, RESULTS. Injury visualized by MRI at 72 hours after hypoxia correlated stro ngly with histopathologic analysis. Transient injury was identified, MK-801 significantly reduced the lesion extent at the level of the hippocampus, P atterns of unilateral versus bilateral neonatal brain injury were found to differ, CONCLUSIONS. The study demonstrates unique patterns of brain injury not see n in adult animal hypoxia-ischemia studies, and the sensitivity of the corp us callosum to hypoxia ischemia, MK-801, although neuroprotective, did not offer any selective neuroprotective benefit.