A transparent black non-diffusing micelle gel for optical CT performance evaluation phantoms

Performance evaluation of optical CT scanners requires a set of phantoms with well known optical and geometric properties. Gels are often used and tinted with colouring agents but these suffer from wavelength dependencies, diffusion and degradation over time. In this paper we describe a new approach to creating suitable test phantoms using micelles. Adding surfactants to gelatin hydrogels allows materials insoluble in water to become suspended. Carbon black nanoparticles were dissolved into a transparent hydrogel consisting of 4% gelatine and 0.2% Triton X-100. The lack of macroscopic diffusion of the black particles was demonstrated by recording transmission images over 500 hours.