^(99)Tc^m-HL91脑缺血半暗带显像的实验研究

An experimental study on cerebral ischemic penumbra imaging with ^(99)Tc^m-HL91

目的 观察99Tcm 4,9 二氮 3,3,10 ,10 四甲基十二烷 2 ,11 二酮肟 (HL91)在局部脑缺血模型脑组织中分布特点。方法 建立 31只大鼠局部脑缺血模型 ,对99Tcm HL91在正常大鼠体内以及在动物模型脑组织中的分布进行研究 ,同时对动物模型脑组织行放射自显影研究。结果 99Tcm HL91静脉注射后主要分布于肝、肾、小肠 ,正常脑组织放射性较低。患 /健侧大脑中动脉主要供血区(靶区 )单位质量放射性比值与对照组相比差异均有显著性 ,且随时间的延长而逐渐增高。动物模型脑组织自显影图像均可见靶区放射性明显高于对侧镜像部位 ,经计算机图像分析系统进行图像分析和数据处理后 ,同一时相靶与非靶区单位面积净吸光度值差异有显著性 ,各时相靶 /非靶比值与对照组比较差异均有显著性 ,且随注射药物时间的延长而增高。结论 99Tcm HL91能够选择性地浓集于缺血缺氧的脑组织中 ,清除延缓 ,可用于急性脑卒中缺血半暗带的探测。

Objective To investigate the biodistribution of 99 Tc m-4,9-diaza-3,3,10,10-tetramethyldodecan-2,11-dione dioxime (HL91) in rat model of middle cerebral artery occlusion (MCAO). Methods Thirty-one MCAO rats were established. Fourteen rats were used to study the biodistribution of 99 Tc m-HL91 and 15 rats were used to study the distribution of 99 Tc m-HL91 in the brain of MCAO model rats. Autoradiographic study of brain was also done in 16 MCAO model rats. Results The liver and kidney retention were higher than that in other tissues. At 1 h after injection, small intestine retention was also high.But radioactivity in normal brain was low. Retention in target site was higher than that in non-target site. Difference between subgroups of operation and that of pseudo-operation was significant( P <0.05 to P <0.001). Regional selective retention of 99 Tc m-HL91 at the target-ischemic area was shown in the autoradiograph. By using computer-enhanced image analysis, difference between target site and non-target site in the same autoradiograph and the differences between operation subgroups and that of pseudo-subgroups were all significant via Dunnett t -test and One-Way ANOVA. Conclusions 99 Tc m-HL91 can be avidly taken up by ischemic penumbra and target/non-target ratio is high. 99 Tc m-HL91 is a potential agent for hypoxic tissue imaging, and 99 Tc m-HL91 SPECT is a promising modality in detecting the ischemic penumbra.