超早期脑梗塞及再灌注动物模型的磁共振弥散加权成像研究

目的

Study on Hyperacute Cerebral Infarction and Reperfusion in Rat with

ObjectiveTo observe the appearance of hype racute cerebral infarction and reperfusion in rat model after middle cerebral ar tery occlusion (MCAO) on diffusion weighted imaging and to study the relevant p athologic basis. Materials and MethodsTwenty seven Wistar rats w ere divided into 5 groups: group 1 (〖WTBXn〖WTBZ=6), non reperfusion; grou p 2, 3 and 4 (〖WTBXn〖WTBZ=4 for each), reperfusion at 30min, 1h and 2h oft er MCAO, respectively; group 5 (〖WTBXn〖WTBZ=9), sacrificed at different in tervals after MCAO for histologic and electro microscopic examination. DWI and T2WI at different intervals were performed in all rats of group 1～4. TTC was done after the last examination. Apparent diffusion coefficient (ADC), relative ADC (rADC) and the area of hyper intensity on DWI and T2WI were measured. ResultsDWI demonstrated hyper intensity in the ipsilateral hemisphere at 30min after MCAO in all rats, while T2WI showed nor mal. With the lapse of time, DWI signal intensity and the area of hyper intensi ty increased. ADC and rADC of abnormal areas continuously declined within 6 hour s after MCAO. Microscopic changes varied from scattered neural cell necrosis at 30 min to diffuse histologic damages at 24h. After reperfusion, abnormal area re covered entirely or partially in both group 2 and group 3, but no obvious change s were found in the rats of group 4. ConclusionDWI is highly sensitive to hyperacute cerebral infarction, it is very helpful in guiding clinical therapy and in evalu ating therapeutic effect.