Study of DWI and PWI in superacute cerebral ischemia

Objective To investigate the Characterization of DWI and PWI during ischemia and reperfusion and their value in the assessment of penumbra in ischemic rats. Methods 70 SD rats were randomly divided into three groups, group A (n=10) was sham-operated for control study, group B, C(n=30 for each) experience the occlusion and reperfusion of the right middle cerebral artery with thread. DWI, PWI were per- formed at B(I2h/R2h, 12h/R24h)and C(I6h/ R2h, I6h/ R24h) respectively. NEI topo- graphical maps were achieved through reconstruction of raw data of DWI and PWI at workstation. The ratios of NEI (relative value to the contralateral side) were measured at areas of ischemic core and border area. Results Rats in group A had no change on DWI and PWI, hyper-intensity was found on DW I in group B. RNEI map in group B showed recovery of perfusion after reperfusion. The recovery of perfusion in group C showed more inadequacy and more uneven, and perfusion deficit still can be seen in the lesion. Conclusion Semi-quantitative parameters of DWI and PWI can distinguish the penum- bra from ischemic necrosis. DWI can reflect the changes of the ischemic lesion, while PWI can monitor changes of blood dynamics following ischemia and reperfusion.