Radiology Unit, IRCCS Policlinico San Donato, San Donato Milanese, Italy.
Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy.
Acta Radiol. 2021 Mar;62(3):334-340. doi: 10.1177/0284185120924563. Epub 2020 May 31.
T1 mapping is emerging as a powerful tool in cardiac magnetic resonance (CMR) to evaluate diffuse fibrosis. However, right ventricular (RV) T1 mapping proves difficult due to the limited wall thickness in diastolic phase. Several studies focused on systolic T1 mapping, albeit only on the left ventricle (LV).
To estimate intra- and inter-observer variability of native T1 (nT1) mapping of the RV, and its correlations with biventricular and pulmonary function in patients with congenital heart disease (CHD).
In this retrospective, observational, cross-sectional study we evaluated 36 patients with CHD, having undergone CMR on a 1.5-T scanner. LV and RV functional evaluations were performed. A native modified look-locker inversion recovery short-axis sequence was acquired in the systolic phase. Intra- and inter-reader reproducibility were reported as complement to 100% of the ratio between coefficient of reproducibility and mean. Spearman ρ and Mann-Whitney -test were used to compare distributions.
Intra- and inter-reader reproducibility was 84% and 82%, respectively. Median nT1 was 1022 ms (interquartile range [IQR] 1108-972) for the RV and 947 ms (IQR 986-914) for the LV. Median RV-nT1 was 1016 ms (IQR 1090-1016) in patients with EDVI ≤100 mL/m and 1100 ms (IQR 1113-1100) in patients with EDVI >100 mL/m ( 0.049). A significant negative correlation was found between RV ejection fraction and RV-nT1 (ρ = -0.284, 0.046).
Systolic RV-nT1 showed a high reproducibility and a negative correlation with RV ejection fraction, potentially reflecting an adaptation of the RV myocardium to pulmonary valve/conduit (dys)-function.
T1 映射作为心脏磁共振（CMR）评估弥漫性纤维化的强大工具正在出现。然而，由于舒张期右心室（RV）壁厚度有限，RV 的 T1 映射证明很困难。几项研究侧重于收缩期 T1 映射，尽管仅针对左心室（LV）。
评估先天性心脏病（CHD）患者 RV 固有 T1（nT1）映射的观察者内和观察者间变异性及其与双心室和肺功能的相关性。
在这项回顾性、观察性、横断面研究中，我们评估了 36 名接受 1.5-T 扫描仪 CMR 的 CHD 患者。进行了 LV 和 RV 功能评估。在收缩期获取固有改良 Look-Locker 反转恢复短轴序列。报告观察者内和观察者间的可重复性，补充了重复性系数与平均值之比的 100%。使用 Spearman ρ 和 Mann-Whitney -检验比较分布。
观察者内和观察者间的可重复性分别为 84%和 82%。RV 的中位数 nT1 为 1022 ms（四分位距 [IQR] 1108-972），LV 的中位数 nT1 为 947 ms（IQR 986-914）。EDVI ≤100 mL/m 的患者 RV-nT1 的中位数为 1016 ms（IQR 1090-1016），EDVI >100 mL/m 的患者为 1100 ms（IQR 1113-1100）（ 0.049）。RV 射血分数与 RV-nT1 呈显著负相关（ρ = -0.284， 0.046）。
收缩期 RV-nT1 具有较高的可重复性，与 RV 射血分数呈负相关，可能反映了 RV 心肌对肺动脉瓣/导管（功能障碍）的适应性。
