通过三相位水平集方法将心脏不同回声强度的区域分割成独立的部分;采用二值图像处理方法提取出心室壁区域,并去除噪声,连通心肌壁区域;最后通过曲线拟合方法对左心室内轮廓进行拟合,分割成光滑闭合的分割曲线。将算法分割结果与医生手动分割结果进行比对后可知,三相位水平集方法能够定性地对左心室进行分割。分别采用基于相对差异度(RDD)、相对重叠度(ROD)和Dice系数对三相位水平集方法的结果进行评估,其中RDD值为0.051,ROD,Dice参数值均接近0.900,说明这三个参数能够定量分析左心室的分割结果。分析表明,算法对心脏心室壁区域有较好分割效果的同时,对心脏腔内噪声不敏感,多种曲线拟合方法对左心室内轮廓拟合效果较好。

This study proposes an ultrasound left ventricular segmentation method. First, the region of the heart with a different echo intensity is divided into independent parts by the three-phase Level Set method. Second, the ventricular wall region is extracted by the binary processing method, and the noise and myocardial wall area are removed and connected, respectively. Third, the left ventricle contour is fitted by the curve fitting method and segmented into a smooth closed segmentation curve. The segmentation results of the proposed algorithm are compared with the doctor's manual segmentation results. The left ventricle is qualitatively segmented. The results are evaluated using three image segmentation evaluation methods, namely, the relative difference degree (RDD), relative overlap degree (ROD), and Dice parameters. The RDD value is 0.051, while the ROD and Dice parameter values are both close to 0.900. The left ventricular segmentation results are quantitatively analyzed. The analysis shows that the algorithm has a good segmentation effect on the heart ventricular wall area, and it is not sensitive to intracardiac noise. A variety of curve fitting methods have a good effect on the left ventricular contour.