【摘要】 目的探讨磁共振R2*值对脑卒中易感性自发性高血压大鼠(SHRsp)自发性脑出血的预测价值。方法高龄雄性SHR模型30只,连续监测血压和定期行磁共振R2*及ESWAN序列扫描。ESWAN序列相位图或幅值图显示脑内任何部位微出血或出血灶为阳性组,记录微出血部位、数目和时期(周龄)。至实验终点76周未发现微出血或出血灶为阴性组。采用重复测量方差分析(Repeated measures ANOVA)比较出血前不同时间点、不同部位的R2*值。出血后处死大鼠,制作病理切片观察并与MRI对比分析。结果阳性组17只,阴性组9只,死亡4只。38~68周阳性组出血侧中心区及对侧镜相区R2*值均平稳上升,68~74周阳性组出血侧中心区R2*值上升较快,对侧镜相区变化相对平缓。阳性组出血前1~2周大脑皮层、基底节区出血侧中心区R2*值骤然升高,明显高于对侧镜相区,差异有统计学意义(P<0.05)。阳性组出血前1~2周大脑皮层、基底节区R2*值出血侧中心区高于阴性组末次,差异均有统计学意义(P<0.05)。R2*值升高的部位与随后出血的位置基本一致。ESWAN图微出血或出血灶分布与病理学观察基本一致。结论 SHRsp在自发性脑出血前1~2周R2*值骤升,R2*值对其出血的时间和部位有较高的预测价值。更多还原

【Abstract】 Objective To investigate the predictive value of MRI R2*values on the Spontaneous Intracerebral Hemorrhage in Stroke Prone Spontaneously Hypertensive Rats. Methods Thirty SHRsp elderly male rats were obtained in accordance with the experimental program of continuous monitoring of blood pressure and regular MRI scans. MRI sequences include ESWAN and R2*. Any part of the phase or magnetic diagrams of the ESWAN sequence that discovered brain microbleeds( or small brain hemorrhages) were recorded into the positive group. We measured the R2*values,observed whether there were microbleeding lesions of the rats’ brains,and recorded the time and locations of microbleeds. When no microbleeds were discovered,the data were recorded in the negative group. Once the rats were found to have microbleeds in ESWAN,the rats were sacrificed right away. Then,pathological examination of brain tissue with MRI images was analyzed. No bleeding group of rats were sacrificed at the end of the experiment. The R2*values were compared at different time points and locations in the rats’ brain before bleeding by Repeated measures ANOVA. Results 17 SHRsp rats underwent spontaneous intracerebral microbleeds or hemorrhage,9 were not bleeding and 4 died during the experiment. R2*values in the central area of the lesion and the contralateral mirror area in positive group steadily rose from 38 to 68 W.However R2*values in the central area of the lesion group in positive group increased faster,from 68 to 74 W. The contralateral mirror area,in contrast,remained relatively flat. In the positive group before bleeding for 1 to 2W,the R2*values in cerebral cortex and basal ganglia lesions were significantly higher than those of the contralateral side of the central part of the mirror area( P < 0. 05). In the positive group R2*the values of the central area in cerebral cortex and basal ganglia lesions were higher than the last time in the negative group,which indicated a significant difference between bleeding times for 1 to 2W( P < 0. 05). After the ESWAN processing image,the distribution of microbleeds was consistent with pathology distribution we observed. The positions where R2*values were elevated in ESWAN were consistent with the positions followed by microbleeds. Conclusion The R2*values were quickly elevated in cortex and basal ganglia followed by microbleeds. Predicting hemorrhage both in space and time is viable with this method.更多还原