1. Department of CardiacSurgery, Shengjing Hospital of China Medical University , No. 36 Sanhao Street, Heping District, Shenyang 110004 Liaoning , China
2. Department of Ultrasound, Shengjing Hospital of China Medical University , No. 36 Sanhao Street, Heping District, Shenyang 110004 Liaoning , China