磁共振T_(1)-mapping特征参数评价扩张型心肌病心肌纤维化及与射血分数的相关性

Evaluation of myocardial fibrosis in patients with dilated cardiomyopathy by magnetic resonance T_(1)-mapping characteristic parameters and its correlation with ejection fraction

目的探讨心血管磁共振(CMR)T_(1)-mapping技术评价扩张型心肌病(DCM)心肌纤维化的价值,分析T_(1)-mapping量化指标与射血分数(EF)的相关性。方法选择2015年至2017年在郑州大学第一附属医院治疗的48例DCM患者(DCM组),其中男性38例,女性10例;年龄24~73岁,平均年龄47.40岁;身高155~178 cm,平均身高169 cm;体质量49~98 kg,平均体质量75.51 kg。同期选择24例健康志愿者作为对照组,其中男性14例,女性10例;年龄28~71岁,平均年龄47.67岁;身高155~179 cm,平均身高167 cm;体质量55~85 kg,平均体质量69.21 kg。全部受试者行3.0 T CMR检查。通过心脏短轴电影图像计算EF。采用改进的Look-Locker反转恢复(MOLLI)序列获取T_(1)-mapping图像。用MATLAB软件提取T_(1)-mapping图像直方图参数,包括5组百分位数(P10、P25、P50、P75、P90)、最小值、最大值、偏度系数(Skewness)、峰度系数(Kurtosis)、标准差(s)、均值等。比较T_(1)-mapping参数与EF的相关性。DCM组根据延时钆增强(LGE)图像是否有强化,将DCM组分为LGE(+)亚组和LGE(-)亚组。结果DCM组EF与对照组比较,差异有显著统计学意义[(21.75±9.31)%vs(55.22±7.39)%。P<0.01]。DCM组分为LGE(+)亚组33例和LGE(-)亚组15例。DCM组均值、s、最大值及P10、P25、P50、P75、P90等T_(1)-mapping直方图参数较对照组显著上升,而EF较对照组显著降低(P<0.01)。均值、s、最大值、P10、P25、P50、P75、P90等T_(1)-mapping参数与EF呈负相关(r=-0.546、-0.380、-0.580、-0.387、-0.502、-0.564、-0.583、-0.562,P<0.05)。结论T_(1)-mapping技术有助于诊断DCM心肌纤维化,尤其是弥漫性心肌纤维化,T_(1)-mapping参数与EF呈负相关。

Objective To investigate the value of cardiovascular magnetic resonance(CMR)T_(1)-mapping technique for evaluating myocardial fibrosis in dilated cardiomyopathy(DCM),and analyze the correlation between T_(1)-mapping quantitative parameters and ejection fraction(EF).Methods Form March 2015 July 2017,a total of 48 patients with DCM(DCM group)were enrolled,which included 38 males and 10 females,aged 24-73 years old with mean age of 47.40 years old;height was 155-178 cm with mean height of 169 cm;body mass was 49-98 kg with mean body mass of 75.51 kg.Meantime,24 healthy volunteers were set as control group,which included 14 males and 10 females,aged 28-71 years old with mean age of 47.67years old;height was 155-179 cm with mean height of 167 cm;body mass was 55-85 kg with mean body mass of 69.21 kg.All of them performed 3.0 T CMR examination,and EF was calculated from cardiac short axis cine images.The modified Look-Locker inversion recovery(MOLLI)sequence was used to obtain T_(1)-mapping images.The MATLAB software was used to extract histogram parameters of T_(1)-mapping images,which included 5 groups of percentiles(P10,P25,P50,P75,P90),minimum value,maximum value,Skewness coefficient(Skewness),Kurtosis coefficient(Kurtosis),standard deviation(s)and mean value.The correlation between T_(1)-mapping parameters and EF was compared.DCM group was divided into late gadoliniumenhanceed LGE(+)subgroup and LGE(-)subgroup according to LGE or non-LGE.Results There was significant difference in EF between DCM group and control group[(21.75±9.31)%vs(55.22±7.39)%.P<0.01].DCM group was divided into LGE(+)subgroup(n=33)and LGE(-)subgroup(n=15).The T_(1)-mapping histogram parameters of mean value,s,maximum value and P10,P25,P50,P75,P90 in DCM group were significantly higher than those in control group,while EF was significantly lower than that in control group(P<0.01).The T_(1)-mapping parameters of mean value,s,maximum value,P10,P25,P50,P75,P90were negatively correlated with EF(r=-0.546,-0.380,-0.580,-0.387,-0.502,-0.564,-0.583,-0.562,P<0.05).Conclusion It is demonstrated that T_(1)-mapping technology is helpful to diagnose myocardial fibrosis in DCM,especially in diffuse myocardial fibrosis,and T_(1)-mapping parameters are negatively correlated with EF value.