MRI study of transient cerebral ischemia in the gerbil: interest of T2 mapping.

RATIONALE AND OBJECTIVES: The aim of this study was to evaluate the diagnostic use of MRI and, more precisely, the use of quantitative T2 imaging at 7 T for the early detection of neuronal cerebral alterations after transient ischemia in the gerbil. METHODS: One hundred forty-seven Mongolian gerbils were separated into four groups for which a bicarotid artery occlusion lasted for 4, 6, 8, or 10 minutes, respectively. The animals were scanned before carotid artery occlusion and at 3, 6, 10, 24, and 48 hours and 5 days after the ischemic incident. MR images were acquired on a Bruker Avance DRX300 mini-imaging system. RESULTS: Our results show that T2 mapping is able to localize brain damage induced by transient ischemia and to detect early perturbations in water content (as early as 6 hours after ischemia). CONCLUSIONS: T2 measurements in the striata are correlated with the severity of the ischemic incident, since the changes observed on the T2 images are directly proportional to the duration of occlusion.