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The first part of focal cerebral ischemia and reperfusion functional MRI study Objective: To study the diffusion-weighted imaging (DWI) and perfusion imaging (PWI) in the rat middle cerebral artery occlusion and reperfusion in the process of dynamic change and pathological basis, and ischemia-reperfusion was observed for neuronal apoptosis. Materials and Methods: 65 SD rats were randomly divided into six groups, suture method right middle cerebral artery occlusion (MCAO) model, A, B, C, D group (each 10) were sham group A , B group was I2h/R2h, I2h/R24h, C group I2h/R2h, I2h/R24h, I2h/R7d, D group I6h/R2h, I6h/R24h. Before reperfusion in each group, at different time points after reperfusion row DWI, PWI, T1WI, T2WI scan, and with TTC staining and pathological examination to compare. Group E (15) Every five were I2h/R2h, I2h/R24h, I2h/R7d, F group (10) Every five were I6h/R2h, I6h/R24h neurons by flow cytometry OK withered Determination of death. Results: B group after reperfusion DWI abnormal signal no significant changes in the relative size (p gt; 0.05), ADC values ??before and after reperfusion did not change significantly (p gt; 0.05). Group C reperfusion rats on day 7 6 DWI see high signal, but no abnormal ADC maps. Group D after reperfusion compared with the previous DWI abnormal signal area increased (p lt; 0.05), ADC values ??before and after reperfusion did not change significantly (P gt; 0.05). Group D ROIs ADC values ??were significantly lower than in group B (P lt; 0.05). B, D 24 hours of reperfusion DWI abnormal signal loss area and TTC stained area showed no significant difference in the relative area (P gt; 0.05). Before reperfusion B, D group right middle cerebral artery territory perfusion defects occur, no significant difference in the scope of its defects (P gt; 0.05), B group PWI abnormal signal is relatively larger than DWI abnormal signal area (P lt; 0.05), D group PWI and DWI abnormal signal no significant difference in the relative area (P gt; 0.05). After reperfusion B, C group CBF, CBV map returned to normal, MTT shows prolonged local blood flow, D group than in the B, C group restoration of blood flow is more uneven, incomplete, localized perfusion defects. Group E I2h/R2h, I2h/R24h, I2h/R7d ischemic cortex neuronal apoptosis percentages were: 3.08%, 41.11%, 14.82%, I2h/R24h when apoptosis peaked, I2h/R7d time Apoptosis ratio declined. Group F I6h/R2h ischemic cortex neuronal apoptosis percentage (28.71%) compared to I6h/R24h (21.99%) is high. Conclusion: With the extension of ischemic time aggravation of brain damage, two hours after ischemia and reperfusion can partially rescue the ischemic penumbra tissue, and ischemia-reperfusion 6 hours then aggravate ischemic brain injury. DWI reflects acute cerebral ischemia-reperfusion brain injury changes, PWI reflect reperfusion brain tissue perfusion. The second part of focal cerebral ischemia and reperfusion Activation of MRI and STAT1/STAT3
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