冠脉CTA联合磁共振T1 mapping评估STEMI患者可挽救心肌的应用价值

目的：应用冠状动脉血管造影（CTA）与磁共振纵向弛豫时间定量（T1 mapping）成像联合评估ST段抬高型心肌梗死（STEMI）患者心肌缺血后血管复流水平及再灌注损伤心肌可挽救程度。方法：收集临床确诊的30例STEMI患者（实验组）和符合纳入标准的20例健康人（对照组）。实验组行冠脉CTA检查和磁共振T1 mapping序列，CTA评估血管复流水平，T1 mapping定量测量心肌危险区体积与可挽救心肌指数。计算实验组与对照组心肌不同节段水平T1值，进行统计学分析。结果：冠脉CTA显示实验组LAD，LCX，RCA责任血管全部复流（100%）；T1 mapping测得STEMI患者心肌危险区30.2±8.8（% LV），心肌核心梗死4.7±1.7（% LV），其可挽救指数为67±16%。实验组危险心肌节段T1值（1 395±108 ms）>远端心肌节段T1值（1062±93 ms）>正常对照组心肌节段T1值（967±78 ms）（P<0.05）。但实验组三支责任血管所支配心肌节段平均T1值无显著性差异（P=0.79）。结论：冠脉CTA技术与磁共振T1 mapping序列可全面、定量评估STEMI患者缺血再灌注损伤心肌可挽救程度，为临床提供影像支持。

Application Value of Coronary CTA Combined with CMR T1 Mapping in Evaluating Salvable Myocardium in Patients with STEMI

Objective:Coronary angiography(CTA) and magnetic resonance longitudinal relaxation time quantification(T1 mapping) imaging were used to evaluate the level of vascular reflow after myocardial ischemia and the salvage degree of myocardial reperfusion injury in patients with STEMI. Methods:Thirty patients with STEMI diagnosed clinically(experimental group) and 20 healthy persons who met the inclusion criteria(normal control group) were collected. In the experimental group, coronary CTA and T1 mapping sequence were performed. The level of vascular reflow was evaluated by CTA. The volume of area at risk and myocardial salvage index were measured quantitatively by T1 mapping. The T1 values of different segments of myocardium in the experimental group and the control group were calculated and statistically analyzed. Results:Coronary CTA showed reflow of all LAD, LCX, RCA responsible vessels in the experimental group, and T1 mapping showed that the area at risk of STEMI patients was 30.2 ±8.8(%LV), myocardial core infarction 4.7 ±1.7(%LV), and the myocardial salvage index was 67 ±16%. STEMI patients T1_AAR value(1395 ±108 ms) > T1_remote value(1062 ±93 ms) > T1_NC value(967 ±78 ms)(P < 0.05). However, there was no significant difference in the average T1 value of myocardial segments dominated by the three responsible vessels in the experimental group(P=0.79). Conclusion:Coronary CTA technique and CMR T1 mapping sequence can comprehensively and quantitatively evaluate the salvage degree of myocardial ischemia-reperfusion injury in patients with STEMI, and provide imaging support for clinic.