Right ventricular (RV) free wall fibrosis is an important component of adverse remodeling with RV dysfunction in pulmonary hypertension (PH). However, no previous reports have compared cardiovascular magnetic resonance (CMR) findings and histological analysis for RV free wall fibrosis in PH. We aimed to assess the feasibility of CMR T1 mapping with extracellular volume fraction (ECV) for evaluating the progression of RV free wall fibrosis in PH, and compared imaging findings to histological collagen density through an animal study. Among 42 6-week-old Wistar male rats, 30 were classified according to disease duration (baseline before monocrotaline injection, and 2, 4, 6 and 8 weeks after injection) and 12 were used to control for aging (4 and 8 weeks after the baseline). We obtained pre and post-contrast T1 maps for native T1 and ECV of RV and left ventricular (LV) free wall for six animals in each disease-duration group. Collagen density of RV free wall was calculated with Masson's trichrome staining. The Kruskall-Wallis test was performed to compare the groups. Native T1 and ECV to collagen density were analyzed with Spearman’s correlation. The mean values of native T1, ECV and collagen density of the RV free wall at baseline were 1541 ± 33 ms, 17.2 ± 1.3%, and 4.7 ± 0.5%, respectively. The values of RV free wall did not differ according to aging (P = 0.244, 0.504 and 0.331, respectively). However, the values significantly increased according to disease duration (P < 0.001 for all). Significant correlations were observed between native T1 and collagen density (r = 0.770, P < 0.001), and between ECV and collagen density for the RV free wall (r = 0.815, P < 0.001) in PH. However, there was no significant difference in native T1 and ECV values for the LV free wall according to the disease duration from the baseline (P = 0.349 and 0.240, respectively). We observed significantly increased values for native T1 and ECV of the RV free wall without significant increase of the LV free wall according to the disease duration of PH, and findings were well correlated with histological collagen density.

中文翻译：

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肺动脉高压右心室的系列 T1 映射：与动物研究中的组织学比较


右心室 (RV) 游离壁纤维化是肺动脉高压 (PH) 中 RV 功能障碍不良重构的重要组成部分。然而，之前没有报告比较 PH 中右心室游离壁纤维化的心血管磁共振 (CMR) 结果和组织学分析。我们的目的是评估 CMR T1 映射与细胞外体积分数 (ECV) 的可行性，以评估 PH 中 RV 游离壁纤维化的进展，并通过动物研究将成像结果与组织学胶原密度进行比较。在 42 只 6 周龄 Wistar 雄性大鼠中，根据疾病持续时间（注射野百合碱前的基线以及注射后 2、4、6 和 8 周）对 30 只进行分类，12 只用于控制衰老（野百合碱注射后 4 周和 8 周）。基线）。我们获得了每个疾病持续时间组中六只动物的 RV 和左心室 (LV) 游离壁的天然 T1 和 ECV 的对比前和对比后 T1 图。用Masson三色染色计算RV游离壁的胶原密度。进行 Kruskall-Wallis 检验来比较各组。使用 Spearman 相关性分析天然 T1 和 ECV 与胶原密度的关系。基线时 RV 游离壁的天然 T1、ECV 和胶原密度平均值分别为 1541 ± 33 ms、17.2 ± 1.3% 和 4.7 ± 0.5%。 RV 游离壁的值没有随老化而变化（P 分别为 0.244、0.504 和 0.331）。然而，这些值根据疾病持续时间显着增加（全部 P < 0.001）。在 PH 中，天然 T1 和胶原密度之间（r = 0.770，P < 0.001）以及 ECV 和 RV 游离壁胶原密度之间（r = 0.815，P < 0.001）之间观察到显着相关性。 然而，根据疾病持续时间，左室游离壁的天然 T1 和 ECV 值与基线相比没有显着差异（分别为 P = 0.349 和 0.240）。我们观察到，根据 PH 病程，右心室游离壁的天然 T1 和 ECV 值显着增加，而左心室游离壁没有显着增加，并且结果与组织学胶原密度密切相关。