几种基于中华小型猪心脏磁共振延时增强图像的心肌梗死体积定量算法的初步比较

目的心脏磁共振(CMR)心肌成像应用钆对比剂延迟强化(LGE)显示冠心病心肌梗死(MI)的价值已得到公认。近年来涌现出多种MI体积的定量方法,但是一直没能达成共识。笔者对比了定量MI体积计算的若干方法在中华小型猪MI模型的应用,以期得到准确度最高的定量MI体积计算方法。方法猪龄3个月中华小型猪6只,行冠状动脉结扎,制作MI模型,1个月后行磁共振扫描(可认为是陈旧MI),随后即取心做TTC染色。运用数学软件MATLAB(2011b)编程对LGE图像先手动勾勒心内膜和心外膜,然后行不同信号强度(SI)阈值(5种倍数标准差:2s、3s、4s、5s、6s)分割,提取MI体积,并与病理切片得到的MI体积进行比较。结果病理切片得到的MI体积为(12.24±4.34)cm3。随着SI阈值增大,5种半自动定量算法得到的MI体积分别为(24.04±6.10)cm3、(17.76±6.41)cm3、(14.29±5.88)cm3、(11.70±5.24)cm3、(9.56±4.73)cm3。采用相关分析显示,TTC染色结果与半自动定量方法得到的结果两两之间的相关系数分别为0.807、0.917、0.952、0.967、0.962。结论 5s半自动定量方法在中华小型猪MI模型MI体积计算中与TTC染色结果相关性好,且无统计学差异。5s是一种行之有效的MI定量方法。

Preliminary comparison of various quantification methods of myocardial infarction model with late gadolinium enhanced MRI in China miniature swine

Objective To compare various quantification methods of myocardial infarction（MI） model in China miniature swine,and obtain the highest accuracy of quantitative MI volume algorithm method. Methods Six three-month-old China miniature swine were performed coronary artery ligation（CAL） to produce MI model, and cardiac magnetic resonance（CMR） scanning（considered old MI） and triphenyltetrazolium chloride（TTC） staining were conducted after 1-month. The mathematical software MATLAB（2011b） was employed to treat LGE images and manually program the endocardial and epicardial outline, followed by different signal intensity（SI） threshold segmentation and MI volume extraction. The volumes of biopsy obtained with MI were compared. Results The volume of MI by pathological staining was（12.24 ± 4.34） cm3. With increasing threshold value of SI, the MI volume obtained from 5 kinds of semi quantitative algorithms was（24.04 ± 6.10） cm3,（17.76 ± 6.41） cm3,（14.29 ± 5.88） cm3,（11.70 ± 5.24） cm3and（9.56 ± 4.73） cm3, respectively. The analysis showed that the correlation coefficient of TTC and semi quantitative algorithms were 0.807, 0.917, 0.952, 0.967 and 0.962, respectively. Conclusion It is demonstrated that 5s semi quantitative method of MI volume has good correlation with TTC staining in China miniature swine model, and there is no statistical differences. The 5s is an effective quantitative method.