肝细胞急性坏死与凋亡的磁共振波谱研究

MR spectroscopy study on acute hepatocyte necrosis and apoptosis

目的建立大鼠肝细胞坏死和凋亡的动物模型,将不同时间点的MRS检测结果与病理学所见进行对照研究,以评估MRS检测及鉴别肝细胞凋亡和坏死的能力与价值。方法72只S-D大鼠随机分成假手术对照组、右侧肝动脉与门静脉分支均结扎组(HA+PV组)和单独右侧门静脉分支结扎组(PV组),实验组各分成4个亚组,每个亚组6只,分别于术后3 h1、2 h2、4h7、2 h行普通MRI和单体素PRESS 35序列MRS,得到肝右叶与左叶各代谢物浓度,以及肝右叶内代谢物相对比值。结果HA+PV及PV组术后3 h,少量肝细胞发生坏死与凋亡时,肝右叶Lip-Lac较左叶相比即有明显增高,随着凋亡与坏死细胞增多,Lip-Lac增高更加明显。术后12 h肝右叶Cho较左叶相比出现降低,也随时间延长逐渐明显;肝右叶Lip-Lac/Cho比值在HA+PV及PV组术后3 h均有增高,以PV 3 h组增高更显著。结论凋亡与坏死组织在1H MRS中都有Lip-Lac增加,Cho降低。肝细胞凋亡后早期,Lip-Lac/Cho比值增高较坏死明显,采用Lip-Lac/Cho比值对鉴别早期肝细胞坏死与凋亡具有一定意义。

Objective To study the performance and value of MR spectroscopy(MRS) in detecting and characterizing hepatic necrosis and apoptosis in vivo by a comparison with pathological findings in animal model after ligation of hepatic blood-supplying vessels.Methods Seventy-two SD rats were randomly divided into three groups:a sham operated control group,a necrosis group with both right hepatic artery and right portal vein ligated(HA+PV group),and an apoptosis group with only right portal vein ligated(PV group).There were 4 sub-groups(6 rats each) in the HA+PV group or PV group.The rats in each group were examined by MRI and Single Voxel PRESS 35 sequence for spectroscopic analysis.The peak and area of metabolites were measured and the ratios between right and left lobes were calculated.Results At 3 h in both HA+PV group and PV group, compared with left lobe,the Lip-Lac peak of right hepatic lobe increased obviously with few necrotic and apoptic cells.Along with increasing necrotic and apoptic cells,the Lip-Lac peak of right hepatic lobe increased.Similarly,Cho of the right hepatic lobe decreased at 12 h after operation and more obviously thereafter.The ratios of Lip-Lac/Cho of right lobe increased in both HA+PV and PV groups at 3 h after operation,and more obviously in the PV 3 h sub-group.Conclusions There are an increase of Lip-Lac peak and a decrease of Cho in either necrotic or apoptic tissue.The ratio of Lip-Lac/Cho increases more obviously in apoptic tissue than in necrotic tissue in very early stage and has significance in differentiating acute necrosis and apoptosis.