Efficient Method for Analyzing MR Real-Time Cines: Toward Accurate Quantification of Left Ventricular Function
Efficient Method for Analyzing MR Real-Time Cines: Toward Accurate Quantification of Left Ventricular Function
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DOI：
10.1002/jmri.24869
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发表时间：
2015-10-01
影响因子：
4.4
通讯作者：
Chung, Yiu-Cho
中科院分区：
文献类型：
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作者：
Wu, Yin;Jiang, Ke;Chung, Yiu-Cho
背景资料：为了开发和评估一种有效的方法，以确定呼气末舒张末（艾德）和收缩末（ES）图像的准确定量的左心室（LV）功能的实时电影imaging.Methods：ECG自由呼吸实时电影成像进行短轴切片的13名健康志愿者在3特斯拉。应用K-means聚类分割来描绘心内膜轮廓，由此在每个电影图像中确定LV质心和腔面积。过滤LV质心沿上下方向的位移沿着，以提取每个切片中的呼吸运动。然后识别呼气末艾德和ES图像并用于LV功能定量。使用双尾配对Student t检验、线性回归分析和Bland-Altman图，使用切片匹配标准ECG门控屏气分段电影测量的准确度评价准确度。结果：该方法识别的定性、呼气末艾德和ES图像与逐帧目视检查结果的一致率为97.5%（P>0.05）。在定量方面，观察到实时电影和标准分段电影之间LV功能指数的良好一致性，心肌质量平均差异为0.1 +/- 0.9 g，艾德体积平均差异为-0.3 +/- 1.0 mL，ES体积平均差异为0.2 +/- 1.2 mL，每搏输出量平均差异为-0.2 +/- 1.3 mL，射血分数为-0.3 +/-0.8%。两组左室功能值呈强相关（r >= 0.96），无显著性差异（P>0.05）。实时电影和标准分段电影显示出相似的观察者内变异性（分别为1.2-3.3%和1.1- 2.8%）和观察者间变异性（分别为2.6-6.9%和1.8- 4.8%），所有P值>0.05。所有的变异性是可比的发表results.Conclusion：与费力的逐帧目视检查相比，传统的采用，所提出的方法是有效的，在分析实时电影准确定量的LV功能，而无需过多的手动交互。
Background: To develop and assess an efficient method to identify end-expiratory end-diastolic (ED) and end-systolic (ES) images for accurate quantification of left ventricular (LV) function in real-time cine imaging.Methods: ECG-free free-breathing real-time cine imaging was performed on short-axis slices of thirteen healthy volunteers at 3 Tesla. K-means cluster segmentation was applied to delineate the endocardial contour, from which the LV centroid and cavity area were determined in each cine image. LV centroid displacement along the superior-inferior direction was filtered to extract respiratory motion in each slice. End-expiratory ED and ES images were then identified and used for LV function quantification. Accuracy was evaluated with that measured from the slice-matched standard ECG-gated breathhold segmented cines using two-tail paired Student's t-tests, linear regression analyses and Bland-Altman plots. Intra-and interobserver variability was calculated for each imaging technique.Results: Qualitatively, end-expiratory ED and ES images identified with the proposed method agreed with those determined by frame-by-frame visual inspection in 97.5% of cases (P>0.05). Quantitatively, good agreement of LV function indices between the real-time cine and the standard segmented cine was observed with averaged differences of 0.1 +/- 0.9 g for myocardium mass, -0.3 +/- 1.0 mL for ED volume, 0.2 +/- 1.2 mL for ES volume, -0.2 +/- 1.3 mL for stroke volume, and -0.3 +/- 0.8% for ejection fraction. Paired LV function values exhibited strong correlation (r >= 0.96) and no significant difference (P>0.05). The real-time cine and the standard segmented cine showed similar intra- (1.2-3.3% and 1.1-2.8%, respectively) and interobserver variability (2.6-6.9% and 1.8-4.8%, respectively) with all P-values>0.05. All the variability was comparable with published results.Conclusion: Compared with the laborious frame-by-frame visual inspection, as conventionally adopted, the proposed method is efficient in analyzing real-time cines for the accurate quantification of LV function without excessively manual interactions.