Development and Testing of an Ultrasound-Compatible Cardiac Phantom for Interventional Procedure Simulation Using Direct Three-Dimensional Printing

Abstract

Organ phantoms are widely used for evaluating medical technologies, training clinical practitioners, as well as surgical planning. In the context of cardiovascular disease, a patient-specific cardiac phantom can play an important role for interventional cardiology procedures. However, phantoms with complicated structures are difficult to fabricate by conventional manufacturing methods. The emergence of three-dimensional (3D) printing with soft materials provides the opportunity to produce phantoms with complex geometries and realistic properties. In this work, the aim was to explore the use of a direct 3D printing technique to produce multimodal imaging cardiac phantoms and to test the physical properties of the new materials used, namely the Poro-Lay series and TangoPlus. The cardiac phantoms were first modeled using real data segmented from a patient chest computer tomography (CT) scan and then printed with the novel materials. They were then tested quantitatively in terms of stiffness and ultrasound (US) acoustic values and qualitatively with US, CT, and magnetic resonance imaging systems. From the stiffness measurements, Lay-fomm 40 had the closest Young's modulus to real myocardium with an error of 29-54%, while TangoPlus had the largest difference. From the US acoustics measurements, Lay-fomm 40 also demonstrated the closest soft tissue-mimicking properties with both the smallest attenuation and impedance differences. Furthermore, the imaging results show that the phantoms are compatible with multiple imaging modalities and thus have potential to be used for interventional procedure simulation and testing of novel interventional devices. In conclusion, direct 3D printing with Poro-Lay and TangoPlus is a promising method for manufacture of multimodal imaging phantoms with complicated structures, especially for soft patient-specific phantoms.

A customizable anthropomorphic phantom for dosimetric verification of 3D‐printed lung, tissue, and bone density materials

“…20 Different tissue type inserts can be made within an anthropomorphic setting to validate dual-energy CT contrast resolution of the various tissue types, which is important for particle therapy dose calculation modeling as mapping the stopping power ratio for different tissue types is one of the key sources in beam range uncertainty. Other advanced applications also include molecular imaging, 43 ultrasound cardiac applications, 44 adaptive radiotherapy for Magnetic Resonance (MR)-guided system, 45 and radiomics-based texture metrics. 46…”

Cardiac Radiofrequency Ablation Simulation Using a 3D-Printed Bi-Atrial Thermochromic Model

“…The overall model size was 72 × 66 × 160 mm. The LA dimensions were 38-44 mm, which fall within the typical range [8]. The RA dimensions were 29-35 mm, which also fall within the typical range [15].…”

“…In our previous work [8], we found the X-ray attenuation of Layfomm-40 cardiac models was only marginally different to that of water. Therefore, since the models need to be immersed in a water tank as part of the simulation, these un-modified models are not easily visualized in X-ray fluoroscopy.…”

“…Once the 3D print is soaked in water, the PVA dissolves and leaves a spongey, microporous TPE composite which mimics soft tissue. In our work, we found Layfomm-40 to be an excellent material for creating cardiac models in terms of soft material properties and imaging properties [8].…”

“…This is particularly relevant in the rehearsal of complex surgical/interventional procedures, also allowing for anatomical variation between patients. In our previous work, we evaluated the use of 3D-printed thermoplastics for creating patient-specific whole heart models that were multimodal-imaging-compatible [8]. We investigated a low-cost, soft-tissue-mimicking copolymer filament, known as Layfomm-40 from the Poro-Lay series (CC-Products, Köln, Germany) [9,10].…”