摘要
目的 初步探讨MRI有效横向弛豫时间图（T2＊ map）序列对兔心肌铁超负荷模型心肌铁负荷定量评价的可行性.方法 日本长耳兔11只,分为心肌铁超负荷组（10只）和正常对照组（1只）.采用兔大腿深部肌内注射50 mg/kg右旋糖酐铁剂,制作心肌铁超负荷模型,注射12周.于注射铁剂前、注射铁剂后l～12周每周分别行血清铁和MR检查,MR扫描序列包括心脏短轴面和肝脏横轴面的T2＊ map序列,并测量心脏和肝脏的T2＊和弛豫效率（R2＊）值.于注射铁剂前、注射铁剂后1～8、11、12周的MR扫描完成后分别处死1只动物,剥离心脏和肝脏标本,进行离体MR扫描,扫描序列和测量方法同在体心脏和肝脏.MR扫描完成后切取左心室中间段心肌和部分肝组织进行石蜡包埋及普鲁士蓝染色.Pearson相关分析用于评价各测量参数之间的关系.结果 心肌T2＊[（32.5±8.3）ms]、R2＊值[（38.4±7.9）Hz]与注入铁含量[（1 033.2±673.4） mg]呈显著线性相关（r值分别为-0.799和0.770,P值分别为0.001和0.002）.心肌T2＊值与肝脏T2＊值无显著相关性（r=0.566,P=0.070）.在体心脏和肝脏T2＊值分别为（32.5±8.3）和（8.8 ±5.4）ms,与离体心脏和肝脏T2＊值[（19.4±6.5）和（9.8±5.0）ms]相关性均强（r =0.757,P=0.007和r=0.861,P=0.001）.在体与离体心脏和肝脏的T2＊和R2＊值与血清铁相关性均无统计学意义（P值均＞0.05）.随着注入铁含量的增加,心肌内蓝染颗粒逐渐增多；肝窦和肝细胞内蓝染颗粒显著增加.结论 MRI的T2＊ map无创定量心肌铁负荷是可行的,可以为临床铁超负荷患者早期检出心肌铁超负荷提供可靠依据.
Objective To preliminarily investigate the feasibility of MRI-T2＊ map in evaluating myocardial iron load of myocardial iron overload rabbit models.Methods Eleven rabbits were included in this study and divided into two groups,myocardial iron overload group （n =10） and the control group （n =1）.Iron dextrin （dose of 50 mg/kg） was injected in muscles of thigh once a week,totally 12 weeks.Serum iron test and MRI examination were performed before iron injection,and 1 week to 12 weeks after iron injection.MRI scan protocol included short axial T2＊ map of the left ventricle and cross-section T2＊ map of the liver.T2＊ and R2＊ of the heart and the liver were measured.One rabbit was killed after MRI examination at pre-iron injection,1 week to 8 weeks,11 weeks and 12 weeks after iron injection,respectively.Heart and liver were avulsed to undergo in vitro MRI scan and then paraffin embedded for pathological slices.MRI scan protocol and measurements of the heart and the liver samples were the same to that of in vivo ones.Pearson correlation was used to calculate the relationships between the parameters.Results Myocardial T2＊ [（32.5 ± 8.3 ms）] and R2＊ values [（38.4 ± 7.9） Hz] had significant correlation with injecting iron content（1 033.2 ± 673.4 mg）,the Pearson coefficients were-0.799 （P =0.001） and 0.770 （P =0.002）,respectively.Myocardial T2 had no significant correlation with liver T2＊ values （r =0.556,P =0.070）.T2＊ values of heart and liver in vivo [（32.5 ± 8.3） ms and （8.8 ± 5.4） ms],respectively had strong correlation with those in vitro [（19.4 ± 6.5） ms and （9.8 ± 5.0） ms],respectively （r =0.757,P =0.007 and r=0.861,P=0.001）.T2＊ and R2＊ values of the heart and the liver in vivo and in vitro had no significant correlations with serum iron （P 〉 0.05）.On Prussian blue staining slices,blue particles of myocardium,sinus hepaticus and hepatocyte increased with injecting iron content.Conclusions It is feasible for MRI-T2＊ map to evaluat
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2014年第3期236-240,共5页
Chinese Journal of Radiology
关键词
磁共振成像
心肌
动物实验
Magnetic resonance imaging
Myocardium
Animal experiment
