Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Key Laboratory for MRI, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, P.R. China.
Cardiology Division, West China Hospital, Sichuan University, Chengdu, Sichuan, P.R. China.
J Magn Reson Imaging. 2017 Sep;46(3):905-914. doi: 10.1002/jmri.25618. Epub 2017 Jan 27.
To evaluate the feasibility of a proposed cardiorespiratory-resolved analysis in left ventricular (LV) function quantification from real-time cines in a cohort of cardiac patients.
Electrocardiograph (ECG)-free free-breathing real-time cine imaging based on the balanced steady-state free precession technique was performed on short-axis slices of 20 cardiac patients at 3T. K-means cluster segmentation was used to delineate the endocardial contours, from which the LV centroid and cavity area were determined. Respiratory and cardiac signals were respectively resolved from the filtered LV centroid displacement and time-varied LV cavity area to identify end-expiratory end-diastolic (ED) and end-systolic (ES) images. The obtained LV cavity areas and derived volumetric function indices, including ED volume (EDV), ES volume (ESV), stroke volume (SV), and ejection fraction (EF), were compared with those measured from manual analysis using two-tailed paired Student's t-tests, linear regression analyses, and Bland-Altman plots. Interobserver variability was calculated.
The LV cavity area was strongly correlated between the proposed and conventional manual methods (r > 0.87) for three representative slices at the base, middle ventricle, and apex. The average differences between the two methods were 0.66 ± 3.22 mL for EDV, -0.02 ± 2.68 mL for ESV, 0.67 ± 3.73 mL for SV, and 0.17 ± 2.30% for EF. All paired measures exhibited strong correlations (r > 0.96) without significant differences (P = 0.38-0.98). Acceptable interobserver variability (0.19-3.55%) and strong correlations (r > 0.96) were shown for all measures between the two observers.
The proposed method is feasible for efficient measurement of LV function from real-time cines.
2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:905-914.
评估在一组心脏患者的实时电影中，通过提出的心呼吸分辨分析来定量左心室（LV）功能的可行性。
在 3T 上对 20 例心脏患者的短轴切片进行基于平衡稳态自由进动技术的无心电图（ECG）自由呼吸实时电影成像。采用 K-均值聚类分割来描绘心内膜轮廓，从而确定 LV 质心和腔面积。从滤波的 LV 质心位移和时变的 LV 腔面积中分别分辨呼吸和心脏信号，以识别呼气末舒张末期（ED）和收缩末期（ES）图像。获得的 LV 腔面积和衍生的容积功能指数，包括 ED 容积（EDV）、ES 容积（ESV）、SV 和 EF，与手动分析测量的结果进行比较，采用双尾配对学生 t 检验、线性回归分析和 Bland-Altman 图。计算了观察者间的可变性。
在基底、中部心室和心尖的三个代表性切片上，LV 腔面积与提出的和传统的手动方法之间具有很强的相关性（r>0.87）。两种方法之间的平均差异为 EDV 为 0.66±3.22mL，ESV 为-0.02±2.68mL，SV 为 0.67±3.73mL，EF 为 0.17±2.30%。所有配对测量均表现出很强的相关性（r>0.96），且无显著差异（P=0.38-0.98）。两位观察者之间所有测量的观察者间可变性均良好（0.19-3.55%）且相关性很强（r>0.96）。
提出的方法可用于从实时电影中高效测量 LV 功能。
2 技术功效：阶段 1 J. MAGN. RESON. IMAGING 2017;46:905-914.
