A physiologic regurgitant cardiac valve phantom for magnetic resonance imaging or color Doppler ultrasound study

The goals of the study described were: (1) to develop a computer-controlled regurgitant cardiac valve phantom, compatible with artifact-free magnetic resonance imaging (MRI) and color Doppler ultrasound (CFM); (2) to create regurgitant lesions in the phantom which appear similar to those detected clinically, (3) to measure physiologic pressure differences between chambers, compliances, and regurgitant fractions as seen in mild, moderate, and severe regurgitation. Mean chamber pressure differences ranged from 43-142 mmHg over the range of diseases simulated, regurgitant flow rates ranged from approximately 0.54-18.6 L/min, and compliance values ranged from 0.83 to 21.95 cc/mmHg fluid. No coherent or incoherent artifacts were observed in MRI or CFM images. Images showed a high degree of similarity to regurgitant lesions detected with each modality, confirming that all design goals were met. The system should allow extensive comparative analysis of Doppler ultrasound and MRI flow jets under a wide range of controllable hemodynamic conditions in future experiments.