Zhang Shi-Jun, Chang Di, Jin Ji-Yang, Wang Ya-Ling, Wang Lin, Wang Yuan-Cheng, Wang Zhen, Ju Shenghong
Department of Radiology, Zhongda Hospital, Jiangsu Key Laboratory of Molecular and Functional Imaging, Medical School of Southeast University, Nanjing, China.
Department of Anesthesiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China.
Front Cardiovasc Med. 2022 Mar 17;9:791963. doi: 10.3389/fcvm.2022.791963. eCollection 2022.
The extracellular volume fraction (ECV) derived from cardiac magnetic resonance imaging (MRI) is extensively used to evaluate myocardial fibrosis. However, due to the limited histological verification in healthy individuals, it remains unclear whether the size of cardiomyocytes may play a potential role in the physiological changes of ECV. The aim of this study was to examine the association between cardiomyocyte size and myocardial ECV by using a healthy porcine model.
Sixteen domestic healthy pigs were anesthetized and underwent cardiac MRI with mechanical controlled breathing. Intravenous contrast medium was introduced at a dose of 0.2-0.25 mmol/kg. The interventricular septum ECV was calculated using an established MRI procedure, which was based on the pre- and post-contrast T1 values of the heart and individual blood hematocrit. The cardiomyocyte breadth (CmyB) in cross section was measured by hematoxylin and eosin staining to reflect the cardiomyocyte size.
Data were successfully acquired from 14 pigs. The CmyB was obtained from the myocardial tissues corresponding to the region of interest on cardiac MRI. The mean ± SD of the ECV was 0.253 ± 0.043, and the mean ± SD of the CmyB was 10.02 ± 0.84 μm. The ECV exhibited a negative correlation with the CmyB ( = -0.729, = 0.003).
The myocardial ECV detected by cardiac MRI is negatively correlated with the CmyB in healthy pigs, demonstrating that the size of cardiomyocytes is potentially associated with the ECV under physiological conditions.
源自心脏磁共振成像（MRI）的细胞外容积分数（ECV）被广泛用于评估心肌纤维化。然而，由于健康个体的组织学验证有限，心肌细胞大小是否可能在ECV的生理变化中发挥潜在作用仍不清楚。本研究的目的是使用健康猪模型检查心肌细胞大小与心肌ECV之间的关联。
16只家养健康猪被麻醉并在机械控制呼吸下接受心脏MRI检查。以0.2 - 0.25 mmol/kg的剂量静脉注射造影剂。使用既定的MRI程序计算室间隔ECV，该程序基于心脏造影前和造影后的T1值以及个体血细胞比容。通过苏木精和伊红染色测量横截面中的心肌细胞宽度（CmyB）以反映心肌细胞大小。
成功从14只猪获取数据。CmyB取自与心脏MRI上感兴趣区域相对应的心肌组织。ECV的平均值±标准差为0.253±0.043，CmyB的平均值±标准差为10.02±0.84μm。ECV与CmyB呈负相关（r = -0.729，P = 0.003）。
心脏MRI检测到的心肌ECV与健康猪的CmyB呈负相关，表明在生理条件下心肌细胞大小可能与ECV相关。
