Design of a fatty plaque phantom for validation of strain imaging

Abstract

Prior to clinical application of novel techniques such as vascular elastography and photo acoustic imaging, validation studies are of great importance. Gelatin, agar and polyvinyl-alcohol (PVA) phantoms are commonly used. However, more realistic phantoms are needed with complex geometry and different constituents with known properties. For this purpose, a fatty plaque phantom (fPP) was designed. A 15 weight percent (wt%) PVA solution was made, and 1 wt% of silica scatters were added (3 8 nm). The solution was poured in to a custom made mold, acquiring the fPP in four freeze/thaw cycles. B-mode data were acquired using a MyLab70 (Esaote, NL), while being pressurized from 0-80 mmHg. The phantom was imaged using a 3D echo-CT strain imaging method [1], [2], to determine 3D geometry, distension and radial strains. In accordance with the distension data, higher radial strains were found at the lipid inclusion location. In future work, strain data will be compared to numerical models that match the phantoms and experimental conditions to validate the strains measured. Additional stiffening of the PVA using a coagulation bath will be explored, by doing so, increasing the systolic pressure allowed.