Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Department of Radiology, Daejeon Eulji Medical Center, Eulji University School of Medicine, Daejeon, Korea.
Korean J Radiol. 2021 Aug;22(8):1266-1278. doi: 10.3348/kjr.2020.1218. Epub 2021 Apr 23.
We aimed to compare the aortic valve area (AVA) calculated using fast high-resolution three-dimensional (3D) magnetic resonance (MR) image acquisition with that of the conventional two-dimensional (2D) cine MR technique.
We included 139 consecutive patients (mean age ± standard deviation [SD], 68.5 ± 9.4 years) with aortic valvular stenosis (AS) and 21 asymptomatic controls (52.3 ± 14.2 years). High-resolution T2-prepared 3D steady-state free precession (SSFP) images (2.0 mm slice thickness, 10 contiguous slices) for 3D planimetry (3DP) were acquired with a single breath hold during mid-systole. 2D SSFP cine MR images (6.0 mm slice thickness) for 2D planimetry (2DP) were also obtained at three aortic valve levels. The calculations for the effective AVA based on the MR images were compared with the transthoracic echocardiographic (TTE) measurements using the continuity equation.
The mean AVA ± SD derived by 3DP, 2DP, and TTE in the AS group were 0.81 ± 0.26 cm², 0.82 ± 0.34 cm², and 0.80 ± 0.26 cm², respectively ( = 0.366). The intra-observer agreement was higher for 3DP than 2DP in one observer: intraclass correlation coefficient (ICC) of 0.95 (95% confidence interval [CI], 0.94-0.97) and 0.87 (95% CI, 0.82-0.91), respectively, for observer 1 and 0.97 (95% CI, 0.96-0.98) and 0.98 (95% CI, 0.97-0.99), respectively, for observer 2. Inter-observer agreement was similar between 3DP and 2DP, with the ICC of 0.92 (95% CI, 0.89-0.94) and 0.91 (95% CI, 0.88-0.93), respectively. 3DP-derived AVA showed a slightly higher agreement with AVA measured by TTE than the 2DP-derived AVA, with the ICC of 0.87 (95% CI, 0.82-0.91) vs. 0.85 (95% CI, 0.79-0.89).
High-resolution 3D MR image acquisition, with single-breath-hold SSFP sequences, gave AVA measurement with low observer variability that correlated highly with those obtained by TTE.
本研究旨在比较基于快速高分辨率三维（3D）磁共振（MR）图像采集的主动脉瓣口面积（AVA）与传统二维（2D）电影 MR 技术的计算结果。
本研究纳入了 139 例连续的主动脉瓣狭窄（AS）患者（平均年龄±标准差[SD]，68.5±9.4 岁）和 21 例无症状对照者（52.3±14.2 岁）。采用单次屏气的快速高分辨率 T2 准备三维稳态自由进动（SSFP）序列（2.0mm 层厚，10 个连续层面）获取 3D 平面测量（3DP）的 3D 图像。在三个主动脉瓣水平处还获取了二维 SSFP 电影 MR 图像（6.0mm 层厚）用于 2D 平面测量（2DP）。使用连续方程比较基于 MR 图像的有效 AVA 计算结果与经胸超声心动图（TTE）测量值。
AS 组中，3DP、2DP 和 TTE 测量的平均 AVA±SD 分别为 0.81±0.26cm²、0.82±0.34cm²和 0.80±0.26cm²（=0.366）。在一位观察者中，3DP 的观察者内一致性高于 2DP：观察者 1 的组内相关系数（ICC）分别为 0.95（95%置信区间[CI]，0.94-0.97）和 0.87（95% CI，0.82-0.91），观察者 2 分别为 0.97（95% CI，0.96-0.98）和 0.98（95% CI，0.97-0.99）。3DP 和 2DP 之间的观察者间一致性相似，ICC 分别为 0.92（95% CI，0.89-0.94）和 0.91（95% CI，0.88-0.93）。3DP 衍生的 AVA 与 TTE 测量的 AVA 具有更高的一致性，ICC 为 0.87（95% CI，0.82-0.91），而 2DP 衍生的 AVA 为 0.85（95% CI，0.79-0.89）。
采用单次屏气 SSFP 序列的高分辨率 3D MR 图像采集可获得具有低观察者变异性的 AVA 测量值，与 TTE 获得的结果高度相关。
