磁共振组织追踪技术定量评估急性心肌炎左室心肌应变

Magnetic resonance tissue tracking for left ventricular myocardial strain in acute myocarditis

目的应用心脏磁共振组织追踪(CMR-TT)技术定量分析急性心肌炎左室心肌应变。方法收集急性心肌炎患者30例(病例组)及健康志愿者25例(正常对照组),采用西门子Aera1.5T磁共振完成心脏磁共振检查,应用磁共振组织追踪技术定量分析,比较两组心功能指标:左室射血分数(LVEF)、左室舒张末期容积(LVEDV)、左室收缩末期容积(LVESD)、左室每博输出量(LVSV)、心输出量(CO);左室心肌应变参数:左室整体径向应变(RS)、周向应变(CS)、纵向应变(LS)、左室整体径向应变率(RSR)、周向应变率(CSR)、纵向应变率(LSR)。结果病例组LVEF低于正常对照组[(50.72±11.46)%vs.(59.11±4.87)%,P=0.001]。病例组LVESD高于正常对照组[(63.49±23.89)mL vs.(47.38±15.41)mL,P=0.007];两组间LVEDV、LVSV、CO差异无统计学意义(均P≥0.05)。病例组整体RS、CS、LS低于正常对照组[RS:(29.99±10.16)%vs.(40.97±10.03)%,P <0.001;CS:(-15.39±2.86)%vs.(-19.39±2.49)%,P <0.001;LS:(-14.33±2.78)%vs.(-16.60±3.20)%,P=0.01]。病例组的整体RSR、CSR、LSR低于正常对照组[RSR:(2.04±0.66)L/s vs.(3.05±1.04)L/s,P <0.001;CSR:(-0.92±0.21)L/s vs.(-1.19±0.25)L/s,P <0.001;LSR:(-0.84±0.22)L/s vs.(-1.08±0.29)L/s,P=0.002]。病例组左室射血分数≥55%的整体CS、RSR、CSR均低于正常对照组[CS:(-17.16±1.61)%vs.(-19.39±2.49)%,P=0.003;RSR:(2.42±0.58)L/s vs.(3.05±1.04)L/s,P=0.025;CSR:(-1.00±0.10)L/s vs.(-1.19±0.25)L/s,P=0.002]。结论 CMR-TT技术是一项操作简单、无创的分析左室心肌应变的方法,能定量评估急性心肌炎左室心肌应变;相比左室射血分数指标,心肌应变参数能更敏感地反映心脏早期受损。

Objective To quantitatively analyze the left ventricular myocardial strain of acute myocarditis by cardiac magnetic resonance tissue tracking(CMR-TT)technology.Methods 30 cases of acute myocarditis(case group)and 25 cases of healthy volunteers(normal control group)were recruited,Siemens Aera1.5T magnet-ic resonance imaging was used to complete the cardiac magnetic resonance examination and by using magnetic reso-nance tissue tracking technology quantitative analysis was conducted to caompare the following cardiac function in-dex including left ventricular ejection fraction(LVEF),left ventricular end diastolic volume(LVEDV),left ven-tricular end systolic volume(LVESD),left ventricular stroke output(LVSV),cardiac output(CO),left ventricu-lar myocardial strain parameters,left ventricular global circumferential strain(CS),radial strain(RS),the longi-tudinal strain(LS),left ventricular global radial strain ratio(RSR),circumferential strain ratio(CSR),longitu-dinal strain ratio(LSR).Results LVEF in the case group was lower than that in the control group[(50.72±11.46)%vs.(59.11±4.87)%,P=0.001].LVESD in the case group was higher than that in the control group[(63.49±23.89)mL vs.(47.38±15.41)mL,P=0.007].There was no significant difference in LVEDV,LVSV and CO between the two groups(P>0.05).The global RS,CS,LS of the case group was significantly lower than that of the control group[RS:(29.99±10.16)%vs.(40.97±10.03)%,P<0.001;CS:(-15.39±2.86)%vs.(-19.39±2.49)%,P<0.001;LS:(-14.33±2.78)%vs.(-16.60±3.20)%,P=0.01].The global RSR,CSR and LSR in the case group were lower than that in the control group[RSR:(2.04±0.66)L/s vs.(3.05±1.04)L/s,P<0.001;CSR:(-0.92±0.21)L/s vs.(-1.19±0.25)L/s,P<0.001;LSR:(-0.84±0.22)L/s vs.(-1.08±0.29)L/s,P=0.002].The global CS,RSR and CSR of the left ventricular ejection fraction of 55%or more in the case group were lower than those in the control group[CS:(-17.16±1.61)%vs.(-19.39±2.49)%,P=0.003;RSR:(2.42±0.58)L/s vs.(3.05±1.04)L/s,P=0.025;CSR:(-1.00±0.10)L/s vs.(-1.19±0.25)L/s,P=0.002].Conclusion The CMR-FT technique is not only featured by simple and noninvasive,but also can quantitatively evaluate left ventric-ular myocardial strain in acute myocarditis.Compared with left ventricular ejection fraction index,myocardial strain parameter is more sensitive to early cardiac damage.