利用体内磁共振弹性成像技术评估心肌梗死诱导猪模型中的左心室僵硬度。
In vivo magnetic resonance elastography to estimate left ventricular stiffness in a myocardial infarction induced porcine model.
作者信息
Mazumder Ria, Schroeder Samuel, Mo Xiaokui, Litsky Alan S, Clymer Bradley D, White Richard D, Kolipaka Arunark
机构信息
Department of Electrical and Computer Engineering, 205 Dreese Laboratories, Ohio State University, Columbus, Ohio, USA.
Department of Radiology, Ohio State University, Columbus, Ohio, USA.
出版信息
J Magn Reson Imaging. 2017 Apr;45(4):1024-1033. doi: 10.1002/jmri.25432. Epub 2016 Aug 17.
PURPOSE
To estimate change in left ventricular (LV) end-systolic and end-diastolic myocardial stiffness (MS) in pigs induced with myocardial infarction (MI) with disease progression using cardiac magnetic resonance elastography (MRE) and to compare it against ex vivo mechanical testing, LV circumferential strain, and magnetic resonance imaging (MRI) relaxometry parameters (T , T , and extracellular volume fraction [ECV]).
MATERIALS AND METHODS
MRI (1.5T) was performed on seven pigs, before surgery (Bx), and 10 (D10), and 21 (D21) days after creating MI. Cardiac MRE-derived MS was measured in infarcted region (MIR) and remote region (RR), and validated against mechanical testing-derived MS obtained postsacrifice on D21. Circumferential strain and MRI relaxometry parameters (T , T , and ECV) were also obtained. Multiparametric analysis was performed to determine correlation between cardiac MRE-derived MS and 1) strain, 2) relaxometry parameters, and 3) mechanical testing.
RESULTS
Mean diastolic (D10: 5.09 ± 0.6 kPa; D21: 5.45 ± 0.7 kPa) and systolic (D10: 5.72 ± 0.8 kPa; D21: 6.34 ± 1.0 kPa) MS in MIR were significantly higher (P < 0.01) compared to mean diastolic (D10: 3.97 ± 0.4 kPa; D21: 4.12 ± 0.2 kPa) and systolic (D10: 5.08 ± 0.6 kPa; and D21: 5.16 ± 0.6 kPa) MS in RR. The increase in cardiac MRE-derived MS at D21 (MIR) was consistent and correlated strongly with mechanical testing-derived MS (r(diastolic) = 0.86; r(systolic) = 0.89). Diastolic MS in MIR demonstrated a negative correlation with strain (r = 0.58). Additionally, cardiac MRE-derived MS demonstrated good correlations with post-contrast T (r(diastolic) = -0.549; r(systolic) = -0.741) and ECV (r(diastolic) = 0.548; r(systolic) = 0.703), and no correlation with T .
CONCLUSION
As MI progressed, cardiac MRE-derived MS increased in MIR compared to RR, which significantly correlated with mechanical testing-derived MS, T and ECV.
LEVEL OF EVIDENCE
1 J. Magn. Reson. Imaging 2017;45:1024-1033.
目的
使用心脏磁共振弹性成像（MRE）评估猪心肌梗死（MI）疾病进展过程中左心室（LV）收缩末期和舒张末期心肌僵硬度（MS）的变化，并将其与离体力学测试、LV圆周应变和磁共振成像（MRI）弛豫测量参数（T1、T2和细胞外容积分数[ECV]）进行比较。
材料与方法
对7头猪在手术前（Bx）、MI创建后10天（D10）和21天（D21）进行MRI（1.5T）检查。在梗死区域（MIR）和远隔区域（RR）测量心脏MRE衍生的MS，并与D21处牺牲后获得的力学测试衍生的MS进行验证。还获得了圆周应变和MRI弛豫测量参数（T1、T2和ECV）。进行多参数分析以确定心脏MRE衍生的MS与1）应变、2）弛豫测量参数和3）力学测试之间的相关性。
结果
与RR中的平均舒张期（D10：3.97±0.4kPa；D21：4.12±0.2kPa）和收缩期（D10：5.08±0.6kPa；D21：5.16±0.6kPa）MS相比，MIR中的平均舒张期（D10：5.09±0.6kPa；D21：5.45±0.7kPa）和收缩期（D10：5.72±0.8kPa；D21：6.34±1.0kPa）MS显著更高（P<0.01）。D21时（MIR）心脏MRE衍生的MS增加是一致的，并且与力学测试衍生的MS密切相关（r（舒张期）=0.86；r（收缩期）=0.89）。MIR中的舒张期MS与应变呈负相关（r=0.58）。此外，心脏MRE衍生的MS与对比剂后T1（r（舒张期）=-0.549；r（收缩期）=-0.741）和ECV（r（舒张期）=0.548；r（收缩期）=0.703）具有良好的相关性，与T2无相关性。
结论
随着MI进展，与RR相比，MIR中心脏MRE衍生的MS增加，这与力学测试衍生的MS、T1和ECV显著相关。
证据水平
1 J.Magn.Reson.Imaging 2017；45：1024 - 1033。
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