Punithakumar Kumaradevan, Ben Ayed Ismail, Islam Ali, Goela Aashish, Lil Shuo
GE Healthcare, London, Ontario, Canada.
Med Image Comput Comput Assist Interv. 2012;15(Pt 2):527-34. doi: 10.1007/978-3-642-33418-4_65.
This study investigates regional heart motion abnormality detection via multiview fusion in cine cardiac MR images. In contrast to previous methods which rely only on short-axis image sequences, the proposed approach exploits the information from several other long-axis image sequences, namely, 2-chamber, 3-chamber and 4-chamber MR images. Our analysis follows the standard issued by American Heart Association to identify 17 standardized left ventricular segments. The proposed method first computes an initial sequence of corresponding myocardial points using a nonrigid image registration algorithm within each sequence. Then, these points were mapped to 3D space and tracked using Unscented Kalman Filter (UKS). We propose a maximum likelihood based track-to-track fusion approach to combine UKS tracks from multiple image views. Finally, we use a Shannon's differential entropy of distributions of potential classifiers obtained from multiview fusion estimates, and a naive Bayes classifier algorithm to automatically detect abnormal functional regions of the myocardium. We proved the benefits of the proposed method by comparing the classification results with and without fusion over 480 regional myocardial segments obtained from 30 subjects. The evaluations in comparisons to the ground truth classifications by radiologists showed that the proposed fusion yielded an area-under-the-curve (AUC) of 95.9%, bringing a significant improvement of 3.8% in comparisons to previous methods that use only short-axis images.
本研究通过电影心脏磁共振图像中的多视图融合来研究局部心脏运动异常检测。与以往仅依赖短轴图像序列的方法不同,所提出的方法利用了其他几个长轴图像序列的信息,即两腔、三腔和四腔磁共振图像。我们的分析遵循美国心脏协会发布的标准来识别17个标准化的左心室节段。所提出的方法首先在每个序列中使用非刚性图像配准算法计算相应心肌点的初始序列。然后,将这些点映射到三维空间并使用无迹卡尔曼滤波器(UKS)进行跟踪。我们提出了一种基于最大似然的轨迹到轨迹融合方法,以组合来自多个图像视图的UKS轨迹。最后,我们使用从多视图融合估计中获得的潜在分类器分布的香农微分熵,以及朴素贝叶斯分类器算法来自动检测心肌的异常功能区域。通过比较对30名受试者获得的480个局部心肌节段进行融合和不融合的分类结果,我们证明了所提出方法的优势。与放射科医生的地面真值分类相比的评估表明,所提出的融合产生的曲线下面积(AUC)为95.9%,与仅使用短轴图像的先前方法相比有3.8%的显著提高。