MRI心肌成像技术在心肌梗死后存活心肌中的诊断价值

Diagnostic value of myocardial MRI in detecting viability myocardium after myocardial infarction

目的探讨MRI心肌成像技术在心肌梗死后存活心肌诊断中的价值。方法采用1.5TGE Signa CV/iMRI对20例临床确诊为心肌梗死并经冠脉造影证实有心肌缺血的患者进行扫描。采用真正快速稳态梯度回波序列(FIESTA)完成心脏长轴面和短轴面的心脏运动MRI电影采集;快速梯度回波序列(FGREET)完成心肌灌注首过时相MRI图像采集;反转恢复梯度回波序列(MDE)完成心肌灌注延迟时相MRI图像采集。结果首过灌注减低区和延迟增强区与同层面正常区域心肌的时间-信号强度曲线的最大上升斜率(slope)差别显著(分别为t=12.9,P<0.001;t=14.3,P<0.001)。首过期灌注减低12例(60%),延迟期心肌增强19例(95%),延迟强化范围明显大于首过灌注缺损区。多因素线性回归分析显示,延迟强化的范围和与其运动能力呈负相关。结论多种MRI成像序列的应用为正确地评价心肌梗死后存活心肌提供了可靠的方法。

Objective To evaluate the effect of myocardial MRI in detecting viability myocardium after myocardial infarction （MI）. Methods Myocardial MRI was performed on 20 MI patients diagnosed according to clinical standard and proved by coronary angiography （CAG） with 1.5T magnetic resonance. Long and short axis imagines were acquired by cine FIESTA sequence. The tint-pass and delayedphase perfusion imagings were acquired by double echo steady state FGREET and inversion recovery gradin-echo MDE sequences. Results The maximum ascended slope had significant difference between the normal area and hypoenhancement area during the first-pass phase （t = 12.9, P 〈0. 001 ）, and hyperenhancement area during delayed phase （ t = 14. 3, P 〈0. 001 ）. Hypoenhancement area was detected in 12 cases （60%） during the first-pass phase and hyperenhancement area in 19 cases （95%） during delayed phase. The range of delayed phase was larger than that of first-paas phase. The extent of hyperenhancement during delayed phase was negatively related to abnormality of wall motion. Conclusions MRI seauences are oroved to be the most oromising method to evaluate viability mvocardium after MI.