A WORKING CARDIAC-VALVE PHANTOM FOR RADIOGRAPHIC ASSESSMENT OF PROSTHETIC HEART-VALVES

Rationale and Objectives. A working valve phantom (WVP) that both exer cises the valve occluder and simulates movements of the mitral annulus is described. It was designed to develop a method for radiographic de tection of a single broken leg of the two-legged Bjork-Shiley convexo- concave (C/C) heart valve outlet strut. Methods. The WVP consists of a pneumatically driven left ventricular assist device immersed in 22 cm of water, Left ventricular assist device annulus movements are genera ted bf systolic turgor and diastolic relaxation of the aortic outflow graft within limits set by the holding fixture design. Results. WVP im ages were comparable in attenuation, valve motion, and diagnostic sens itivity to clinical C/C valve images and were effective in assessing l eaflet excursions in another valve model, Techniques developed in the WVP have proved successful in the clinical detection of C/C valves tha t have a single broken leg but that show normal function in all other tests. Conclusion. The WVP can be a useful tool for developing refined radiographic assessments of prosthetic heart valves.