Stress CMR T1-mapping technique for assessment of coronary microvascular dysfunction in a rabbit model of type II diabetes mellitus: Validation against histopathologic changes.
Stress CMR T1-mapping technique for assessment of coronary microvascular dysfunction in a rabbit model of type II diabetes mellitus: Validation against histopathologic changes.
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DOI：
10.3389/fcvm.2022.1066332
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发表时间：
2022
影响因子：
3.6
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中科院分区：
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冠状动脉微血管功能障碍（CMD）是2型糖尿病（T2 DM）的早期特征，是不良事件的指征。本研究旨在验证心脏磁共振（CMR）的应力T1标测技术从组织病理学角度识别CMD的性能，并建立T2 DM兔模型中CMD相关参数的时间过程。新西兰白色家兔（n = 30）随机分为对照组（n = 8）、T2 DM 5周组（n = 6）、T2 DM 10周组（n = 9）和T2 DM 15周组（n = 7）。CMR方案包括静息和三磷酸腺苷（ATP）负荷T1标测成像，使用5 b（20 b）3b-改良的look-locker反转-恢复（MOLLI）方案定量负荷T1反应（负荷ΔT1），以及首过灌注CMR定量心肌灌注储备指数（MPRI）。CMR成像后，心肌组织进行苏木精-伊红染色以评价病理变化，Masson三色染色以测量胶原体积分数（CVF），CD 31染色以测量微血管密度（MVD）。采用Pearson相关分析确定CMR参数与病理结果之间的相关性。对照组、T2 DM 5周组、10周组和15周组的应力ΔT1值分别为6.21 ± 0.59%、4.88 ± 0.49%、3.80 ± 0.40%和3.06 ± 0.54%（p < 0.001），并且随着T2 DM持续时间的延长而逐渐减弱。此外，应力ΔT1与CVF和MVD之间存在显著相关性（r分别为-0.562和0.886; p < 0.001）。T2 DM兔应激T1反应与病理组织学指标相关性良好，提示应激T1反应可作为早期T2 DM CMD相关的敏感指标。
Coronary microvascular dysfunction (CMD) is an early character of type 2 diabetes mellitus (T2DM), and is indicative of adverse events. The present study aimed to validate the performance of the stress T1 mapping technique on cardiac magnetic resonance (CMR) for identifying CMD from a histopathologic perspective and to establish the time course of CMD-related parameters in a rabbit model of T2DM. New Zealand white rabbits (n = 30) were randomly divided into a control (n = 8), T2DM 5-week (n = 6), T2DM 10-week (n = 9), and T2DM 15-week (n = 7) groups. The CMR protocol included rest and adenosine triphosphate (ATP) stress T1-mapping imaging using the 5b(20b)3b-modified look-locker inversion-recovery (MOLLI) schema to quantify stress T1 response (stress ΔT1), and first-pass perfusion CMR to quantify myocardial perfusion reserve index (MPRI). After the CMR imaging, myocardial tissue was subjected to hematoxylin-eosin staining to evaluate pathological changes, Masson trichrome staining to measure collagen volume fraction (CVF), and CD31 staining to measure microvascular density (MVD). The associations between CMR parameters and pathological findings were determined using Pearson correlation analysis. The stress ΔT1 values were 6.21 ± 0.59%, 4.88 ± 0.49%, 3.80 ± 0.40%, and 3.06 ± 0.54% in the control, T2DM 5-week, 10-week, and 15-week groups, respectively (p < 0.001) and were progressively weakened with longer duration of T2DM. Furthermore, a significant correlation was demonstrated between the stress ΔT1 vs. CVF and MVD (r = −0.562 and 0.886, respectively; p < 0.001). The stress T1 response correlated well with the histopathologic measures in T2DM rabbits, indicating that it may serve as a sensitive CMD-related indicator in early T2DM.