Design and Validation of Silicone-Based Stenosis Vessel Segments for MRI Vascular Phantoms

Background To support the development of MRI-guided interventions for aortic coarctation, a modular polymer-based vessel phantom with interchangeable stenosis segments was developed. This study focuses on the design and mechanical evaluation of stenosis vessel segments suitable for catheter-based stenting and balloon angioplasty simulations. Methods Four different stenosis models were fabricated using two-layer silicone constructs with varying Shore hardness and outer layer compositions, including brittle coatings and silicone foam. Stenting and balloon dilatation procedures were performed. Manual lumen diameter measurements were obtained before and after each intervention to assess lumen expansion behavior. Results Distinct lumen expansion patterns were observed among the models. The brittle outer layer ruptured as intended during balloon expansion, simulating vessel wall tearing. The foam-reinforced model exhibited constrained dilation at smaller balloon diameters, while models with plain outer layers expanded more uniformly. All vessel segments demonstrated elastic recovery, returning to their initial diameters after unloading, indicating no permanent deformation. Conclusions This vessel phantom enables simulation of varied in vitro stenosis behaviors. The modular silicone-based approach offers high flexibility in simulating different aortic stenoses and can be integrated into flow circuits for dynamic MRI-guided intervention studies. Such phantoms provide a valuable platform for device testing and procedural planning in cardiovascular research.