Mol C R, Verdel G, Heethaar R M, Jambroes G, van der Werf T
Comput Biomed Res. 1984 Dec;17(6):524-34. doi: 10.1016/0010-4809(84)90017-x.
Evaluation of the function of implanted prosthetic valves is important in early diagnosis of valve dysfunction. Björk-Shiley valves contain two radiopaque rings, which are projected as ellipses in cineradiography. From these ellipses the actual valve opening angle can be calculated. A computer-aided method was developed that enables measurement of ellipse characteristics reliably, independent of projection angle and valve opening. It is demonstrated that calculated and real opening angles differ less than 2 degrees with this method. Using the same technique the tilting angle of the valve ring during the cardiac cycle is computed for evaluation of progression of valve dehiscense in case of a paravalvular leak. Application of the method to patient data is illustrated by three cases. The method is suitable for use by technicians. It can be implemented on a small microprocessor system. The method proved to be a powerful tool in the evaluation of patients with implanted Björk-Shiley valves.
评估植入人工瓣膜的功能对于瓣膜功能障碍的早期诊断很重要。Björk-Shiley瓣膜包含两个不透射线的环，在电影血管造影中显示为椭圆形。通过这些椭圆可以计算出实际的瓣膜开口角度。开发了一种计算机辅助方法，该方法能够可靠地测量椭圆特征，而与投影角度和瓣膜开口无关。结果表明，使用该方法计算出的开口角度与实际开口角度的差异小于2度。使用相同的技术计算心动周期中瓣膜环的倾斜角度，以评估瓣周漏情况下瓣膜裂开的进展。通过三个病例说明了该方法在患者数据中的应用。该方法适合技术人员使用。它可以在小型微处理器系统上实现。该方法被证明是评估植入Björk-Shiley瓣膜患者的有力工具。
