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

Noninvasive imaging has proven successful in the evaluation of valvular heart disease; primarily with magnetic resonance imaging (MRI) and color Doppler ultrasound (CFM). However, the relationship between the morphology of regurgitant flow in MRI and CFM, as a function of hemodynamic parameters (chamber pressure difference, lesion size, compliance, etc.) is not understood. The goals for this work were: 1) to develop a computer-controlled regurgitant cardiac valve phantom, compatible with artifact-free CFM and MR imaging, 2) to create regurgitant lesions in the phantom which appear similar to those detected clinically, 3) to produce and 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. Similarly, regurgitant flow rates ranged from approximately 0.54-18.6 L/min. Compliance values ranged from 0.83 to 21.95 cc/mmHg. No coherent or incoherent artifacts were observed in MRI or CFM images. Images show 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.