GRE T_2*WI在超急性期脑内血肿诊断中的应用价值

The application of Gradient-recalled Echo T_2*WI (GRE T_2WI) sequence in diagnosis of hyperacute intracerebral hematoma (ICH)

目的利用动物实验探讨MRIGRE T2*WI扫描序列在诊断超急性期脑内血肿中的应用价值。方法将兔自身血注入脑内形成脑内血肿,分时段进行GRET2*WI及常规序列(T1WI、T2WI)扫描,并结合各时段组织学表现分析MRI图像特征。结果血肿形成3hT2*WI即可清晰显示脑内血肿大小及其轮廓,血肿形成6、12、24h表现与3h相仿呈低信号,边界清。常规扫描序列T1WI、T2WI显示血肿边界欠清。各时段T2WI和T2*WI血肿体积测量值分别为3h(118±45)μl、(310±19)μl,6h(134±60)μl、(301±22)μl,12h(166±49)μl、(290±8)μl,24h(181±13)μl、(257±14)μl。两者差异有统计学意义(P<0.05)。6h以后组织学上可见血肿周围有中性粒细胞及少量小胶质细胞浸润,12h及24h可见血肿中心少量红细胞开始溶解。结论GRET2*WI序列对超急性期脑内出血敏感性较高,结合常规扫描序列可对超急性期脑血肿做出诊断。

Objective To investigate the application of GRE T2WI in diagnosis of hyperacute ICH in experimental animals. Methods Hyperacute ICH model was induced in 32 rabbits with different stages （3h, 6h,12h, 24h） and animals were scanned with GRE T2WI, T1WI and T2WI. MRI images of different stages were analyzed and compared with corresponding histopathological changes. Results GRE T2WI showed hypointensity with clear boundary at 3h, and the images of 6h, 12h and 24h were similar. T2WI and T1WI showed faint hyperintensity. The hematoma volume of T2WI and T2WI was（118±45μl,310 ±19μl） at 3h,（134±60μl,301±22μl）at 6h,（166±49μl,290±8μl）at 12h,（181±13μl,257±14μl）at 24h respectively. The mean volume of T2WI and T2WI were significantly different （P〈0.05）. From 6h on there scattered neutrophils and a few glial cells around the periphery of the hematoma. At 12h and 24h, there showed a little early degeneration of erythrocytes in the center. Conclusion GRE T2WI sequence shows high sensitivity in the diagnosis of hyperacute ICH. Hyperacute ICH can be diagnosed on MRI using GRE T2WI combined with conventional sequences.