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| MRI dynamic changes in the ipsilateral substantia nigra following MCAO cerebral ischemia |
YANG Yan-mei, FENG Xiao-yuan, YAO Zhen-wei, JIANG Sheng-hong,
LIU Han-qiu, ZHANG Fang, TONG Tong, WANG Fei |
| Department of Radiology, the Huashan Hospital of Fudan University, Shanghai 200040, China |
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Abstract Objective: To analyze the MRI features of the substantia nigra(SN) following single side middle cerebral artery(MCA) occlusion by intraluminal thread in rats． Materials and Methods: Healthy adult male Sprague-Dawley rats(n=16) weighting 270 to 320g were divided into two groups randomly: permanent MCA occlusion(MCAO) group included 12 rats, and 4 rats in control group was sham-operated. The T2WI and absolute T2 values of the SN, cortex and striatum on MRI were assessed on 1h, 3h, 6h, 9h, 12h, 1d, 3d and 7d after MCAO using a 3.0T MR scanner. Results: The brains of the animals in the control group showed no noteworthy abnormality on MRI. All the rats in MCAO group showed cerebral infarction involving the ipsilateral cortex and striatum. The T2WI signal intensity of the mentioned lesions in MCAO group showed a dynamic changes according to time. No changes of bilateral SN can be seen on 1h, 3h, 6h, 9h, 12h and 1d after MCAO. On the 3rd day, the SN of the ipsilateral side to the occluded MCA showed obviously higher signal intensity on T2WI than that of the contralateral side with a clear demarcation. No changes of the signal on the contralateral side could be observed. The difference of the T2 value between the bilateral SN was significant. These changes in the ipsilateral SN were not displayed on the 7th day. The trend of the T2 value change of ipsilateral SN was not in-phase with that of cortex and striatum. Conclusions: MR signal changes can be seen in the ipsilateral SN on the 3rd day after MCAO.
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Received: 18 July 2006
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2007, Vol. 18 
