基于7.0 T心脏MR评估2型糖尿病小鼠早期心肌应变改变特点  

Early myocardial strain characteristics in type 2 diabetic mellitus mice evaluated by 7.0 T cardiac MR

作　　者：石春彦 张宏凯 高一峰 张楠[1] 刘东婷[1] 杨琳[1] 徐磊[1] 范占明[1] Shi Chunyan;Zhang Hongkai;Gao Yifeng;Zhang Nan;Liu Dongting;Yang Lin;Xu Lei;Fan Zhanming(Department of Radiology,Beijing Anzhen Hospital,Capital Medical University,Beijing Institute of Heart Lung and Blood Vessel Diseases,Beijing 100029,China)

机构地区：[1]首都医科大学附属北京安贞医院医学影像科,北京市心肺血管疾病研究所,北京100029

出　　处：《中华放射学杂志》2022年第5期569-575,共7页Chinese Journal of Radiology

基　　金：国家自然科学基金(81771791);北京市医院管理中心“青苗”计划专项(QML20190607)。

摘　　要：目的旨在探讨糖尿病心肌病(DCM)早期心肌应变的改变特点。方法60只健康4周龄雄性C57BL/6J小鼠,采用随机数字法分为2型糖尿病(T2DM)组(30只)和对照组(30只)。对照组采用普通饲料喂养,T2DM组采用高脂饲料喂养。喂养4周后,T2DM组单次大剂量腹腔注射链脲佐菌素(STZ)溶液制作T2DM模型,最终造模成功23只。对照组注射等剂量柠檬酸钠缓冲液。造模成功后第4、8、12、16、20和24周作为监测时间点采集实验数据。每个时间点时各组均入组9只小鼠,然后各组随机选取6只用于体重和血糖监测及7.0 T MR图像采集,处死剩余3只用于制作病理切片(天狼星红染色)以观察心肌间质纤维成分及微小血管的情况。MR图像采用心脏MR特征追踪(CMR-FT)技术进行分析,获得左心室整体周向应变峰值(GPCS)和径向应变峰值(GPRS),并测量射血分数(EF)等。观察期内,各组自身不同监测点参数间比较采用单因素方差分析;组间参数比较采取两独立样本t检验。结果观察期内组间血糖值差异均有统计学意义(P<0.05)。观察期(4~24周)内T2DM组小鼠GPCS呈下降趋势,组内差异有统计学意义(F=8.23,P<0.001);与对照组相比,T2DM组小鼠的GPCS于第20、24周时组间差异具有统计学意义。第20周时T2DM组GPCS为-11.4%±2.1%,对照组为-14.3%±1.9%(t=-2.54,P=0.029);第24周时T2DM组为-12.3%±1.7%,对照组为-14.6%±1.8%(t=-2.35,P=0.040)。EF在第24周时组间差异有统计学意义,T2DM组为51%±5%,对照组为62%±6%(t=3.38,P=0.007)。观察期内,T2DM组小鼠GPRS呈下降趋势,但组内和组间均差异无统计学意义(P>0.05)。心肌组织病理切片显示从第12周起T2DM组小鼠心肌间质纤维成分明显增多。结论T2DM小鼠早期即可出现心肌间质纤维化和心肌应变的改变,其中左心室整体周向应变峰值可较EF更早反映DCM的心功能改变。Objective To investigate the characteristics of early myocardial mechanics changes in diabetic cardiomyopathy(DCM).Method Sixty healthy 4-week-old male C57BL/6J mice were randomly divided into the T2DM group(n=30)and the control group(n=30).The T2DM group was fed with high-fat diet for 4 weeks,and accepted injection of a single high-dose of streptozotocin(STZ)intraperitoneally.Finally,the model was established successfully in 23 mice.The control group was fed with a normal diet and treated with citrate buffer liquid at an equal dose as T2DM group.Then,nine mice were randomly selected from each of the two groups every 4 weeks until the end of the 24th week.Six of the nine mice were randomly selected to perform 7.0 T MR scanning after measuring blood glucose and body weight.Cine images were acquired through cardiovascular MR feature tracking(CMR-FT).The obtained parameters included the left ventricle global peak circumferential strain(LV-GPCS),left ventricle global peak radial strain(GPRS)and the ejection fraction(EF),etc.The rest three mice were sacrificed for observation of the changes of interstitial fibers and micro-vessels in myocardial tissue with Sirius red staining.One-way analysis of variance(ANOVA)and t test were used for comparison.Results There were significant differences in blood glucose levels between the two groups during the observation period(P<0.05).In the 4^(th)-24^(th) week,the value of GPCS in T2DM group showed a downward trend,and the difference was statistically significant(F=8.23,P<0.001).Compared with the control group,the value of GPCS in T2DM group was statistically significant at the 20^(th) and 24^(th) week(the 20^(th) week:-11.4%±2.1% in the T2DM group vs.-14.3%±1.9% in the control group,t=2.54,P=0.029;the 24^(th) week:-12.3%±1.7% in the T2DM group vs.-14.6%±1.8% in the control group,t=2.35,P=0.040),while the EF value was different at the 24^(th) week(51%±5% in the T2DM group vs.62%±6% in the control group,t=3.38,P=0.007).There was no significant difference in the GPRS of the T2

关 键 词：磁共振成像 糖尿病 2型 糖尿病并发症 心肌纤维化 特征追踪 心肌应变 小鼠 

分 类 号：R587.1[医药卫生—内分泌]