正常青年人左心室短轴心肌应变特征的MRI研究  

MRI measurement of left ventricle myocardial strain on short axis in normal youth

作　　者：李梦露[1] 李俊超[2] 程流泉[1] 陈韵岱[2] 董蔚[2] 智光[2] 席晓旭 张晓晶[1] LiMenglu;Li Junchao;Cheng Liuquan;Chen Yundai;Dong Wei;Zhi Guang;Xi Xiaoxu;Zhang Xiaojing(Department of Radiology,PIA General Hospital,Belling 100853,China)

机构地区：[1]解放军总医院放射科,北京100853 [2]解放军总医院心血管内科,北京100853

出　　处：《中华放射学杂志》2018年第12期913-918,共6页Chinese Journal of Radiology

摘　　要：目的运用特征追踪技术(FT)测量正常青年志愿者心脏MRI电影成像上心肌短轴各节段的径向与周向应变参数,分析左心室心内膜短轴应变运动的规律,建立径向与周向应变峰值和达峰时间(TTP)参考值范围。方法2015年3月采集29例年龄24~34岁的健康志愿者的心脏电影图像,包括左心室基底、中部和心尖3个典型短轴层面,采用心肌特征追踪软件TOMTEC对MRI电影图像进行分析,获得心脏除心尖外16节段的径向应变、周向应变、径向位移及其应变率和速度的峰值与TTP,总结分析各参数在平面和节段之间的规律。正态分布的数据结果采用方差分析及SNK法比较,非正态分布数据采用Kruskal-Wallis及Wilcoxon秩和检验法进行分析。结果左心室16个节段的径向应变和应变率峰值在心底、中部、心尖3个平面内各节段之间差异均具有统计学意义,无法形成均一的参考值范围;TTP在平面之间也不一致。心底和中部各节段的周向应变和应变率可以形成均一参考值,分别为(-27.09±9.51)%、(1.94±0.98)/s;各节段的TTP均匀一致,分别为0.38(0.08)RR周期、0.54(0.08)RR周期。除外左心室中部层面,左心室径向位移和速度在基心底、中部、心尖3个平面内各节段之间差异具有统计学意义,无法形成均一的参考值范围;但是各节段间径向速度的TTP均匀一致,为0.21(0.04)RR周期。除径向应变率外,基底部和中间部各参数的TTP值差异均无统计学意义。心尖水平测量变异系数大。应变率、位移和速度在个体之间缺乏规律性。结论左心室心肌内膜径向应变的峰值和TTP存在平面间和节段间差异,无法形成统一的参考值范围;左心室心底和中部的周向应变峰值与TTP值、径向速度的TTP可以形成统一的参考值范围。Objective To learn the endocardial strain patterns of the left ventricles on the short-axis views in normal youth volunteers using feature tracking techniques on cine cardiac MR imaging, and to build up the reference ranges of strain peak and time to peak (TTP) for endocardial strain analysis. Methods Twenty-nine normal youth volunteers aged from 24—34 years old were enrolled in the study in march 2015. The Cine MR imaging were acquired using balance FFE sequence with 24 phases for each cardiac cycle. The standard short-axis imaging planes were basal, mid-cavity and apical levels and divided into 16 segments. The peaks and TTPs of myocardial displacement and its velocity, radial and circumferential strain and strain rate and its velocity in each segment were calculated using feature tracking techniques. The data with normal distribution were analyzed by ANOVA and Student-Newman-Keuls (SNK) method, and Kruskal-Wallis and Wilcoxon rank sum test were used for the data without normal distribution. Results The peaks and TTPs of radial strain and strain rate differed in 16-segmental levels and basal, middle and apical plane levels and had no concordant reference ranges. The circumferential strain and strain rate were homogeneous at basal and middle plane levels [(-27.09±9.51)%, (1.94±0.98)/s, respectively]. Their TTPs were homogenous [0.38 (0.08) RR, 0.54 (0.08) RR, respectively], and there were no significant differences in planar-segments or inter-segment level. Except for middle level, the peaks of radial displacement and velocity differed in basal and apical levels and had no concordant reference ranges. But radial velocity TTPs were homogeneous in all 16 segments [0.21 (0.04) RR]. Except for the radial strain rate, TTPs showed no significant difference between basal level and middle level. The measurements at apical level revealed high variance. No regular pattern could be found on individual peak and TTP curves of velocity and strain rate.

关 键 词：心肌应变 左心室 MRI 正常青年人 参考值范围 变异系数 电影成像 径向应变 

分 类 号：R445.2[医药卫生—影像医学与核医学] R542.2[医药卫生—诊断学]