Three-dimensional ultrasound imaging model of mitral valve regurgitation: design and evaluation.

We describe the development of a cardiac flow model and imaging chamber to permit Doppler assessment of complex and dynamic flow events. The model development included the creation of a circulatory loop with variable compliance and resistance; the creation of a secondary regurgitant circuit; and incorporation of an ultrasound imaging chamber to allow two-dimensional (2D) and three-dimensional (3D) Doppler characterization of both simple and complex models of valvular regurgitation. In all, we assessed eight different pulsatile regurgitant volumes through each of four rigid orifices differing in size and shape: 0.15 cm(2) circle, 0.4 cm(2) circle, 0.35 cm(2) slot and 0.4 cm(2) arc. The achieved mean (and range) hemodynamic measures were: peak trans-orifice pressure gradient 117 mm Hg (40 to 245 mm Hg), trans-orifice peak Doppler velocity 560 cm/s (307 to 793 cm/s), Doppler time-velocity integral 237 cm (111 to 362 cm), regurgitant volume 43 mL (11 to 84 mL) and orifice area 0.32 cm(2) (0.15 to 0.4 cm(2)). The model was designed to optimize Doppler signal quality while reflecting anatomic structural relationships and flow events. The 2D color Doppler, 3D color Doppler and continuous wave Doppler quality was excellent whether the data were acquired from the imaging window parallel or perpendicular to the long-axis of flow. This model can be easily adapted to mimic other intracardiac flow pathology or assess future Doppler applications.