大鼠肝肿瘤细胞灶性凋亡MRI表现

目的:建立大鼠肝肿瘤细胞凋亡模型并研究其磁共振成像表现.方法:选取45只肝肿瘤大鼠,随机分成放疗组,酒精注射组及对照组,每组15只,分1d、3d、7d共3个时间点观察;每组大鼠每个时间点均采集磁共振MRI、DWI、~1H-MRS图像,分析磁共振图像,并测量ADC值及~1H-MRS各代谢物波峰下面积,进行统计学处理;磁共振检查后取标本送病理学(HE,TUNEL,PCNA)及电镜检查;将病理学检查结果与磁共振图像对照分析.结果:①病理学检查结果证实放疗组肝肿瘤细胞发生凋亡;酒精注射组肝肿瘤细胞以发生坏死为主;②放疗组同未治疗组比较肿瘤体积减小,T_1 WI信号等低,T_2 WI信号稍减低,DWI信号下降,呈等高信号,内见条片状等低信号区,ADC值增加,Lip、Cho、Lae、Glx峰下降,Cr峰变化不大;③酒精治疗组体积缩小,病灶中央信号强度明显减低,旱条片状,T_1 WI等低信号,T_2 WI低信号;DWI信号不均匀片状减低,ADC值介于正常组织与残留肿瘤组织之间;Lip、Cho、Lac、Glx、Cr各峰明显下降.结论:大鼠肝肿瘤放疗可诱导细胞凋亡,凋亡后磁共振检查有特异性表现.特别是T_2WI、DWI、~1H-MRS,活体检测肿瘤细胞凋亡成为可能.

MRI Appearance of Focal Apoptosis in Rat Liver Tumor

Purpose: To establish tumor apoptosis model in rat liver cell and to study its appearances on MRI.Methods: Forty-five SD rats were randomly divided into three groups: radiation group, injection group with alcohol and no therapy group. All the rats in each group were observed at ID, 3D, 7D after operation and were examined with conventional MRI, DWI, and MRS. The ADC value and the peak value of the metabolites in MRS were measured and analyzed. After that, the rats were sampled for electronic microscopy and pathology exam.HE staining and TUNEL, PCNA, CD34 and VEGF staining were done. The results of MRI and pathology were compared and analyzed. Results: ①Apoptosis tumor cells were detected by pathology examination in radiation group, necroses were found in injection group with alcohol. ②There were some changes between radiation group and no therapy group in MRI, DWI, and MRS, including the decrease of tumor volume, the increase of signal of MRI, the decrease of intension in DWI, the increase of value of ADC, the decrease of peak value of Cho, Glx, Lac, Lip in MRS. ③In injection group with alcohol, the tumor volumes were decreased, and accompany with the decrease of signal in central of tumor, the decrease of local intension in DWI, the decrease of peak value of Cho, Glx, Lac and Lip in MRS. Conclusion: The apoptosis model in rat liver tumor would be made by radiation. There were some characteristic appearances of apoptosis in MRI, especially with T2WI, DWI and MRS. The apoptosis could be monitored in vivo by MRI.