A Potential Material for Use in Ultrasound Phantoms

Abstract

An ideal ultrasonic soft tissue equivalent phantom should exhibit the same speed of sound, the same attenuation coefficient, and the same scattering properties as those possessed by soft tissue; these qualities should agree at all frequencies in the clinical ultrasound range (1 to 15 mHz). Our group has made progress developing a material which exhibits speeds of sound in the range 1520–1650 m/s and attenuation coefficients approximating 1 dB/cm/mHz. In pursuing the creation of such a material, we have concentrated our efforts on pharmaceutical gel mixtures with various additives including preservatives and alcohols for varying the speed of sound. The major concern has been the development of control over the attenuation coefficient so that reasonable agreement can be obtained with published values for human tissues.¹ This has been accomplished through the introduction of uniform concentrations of graphite powder or tiny plastic spheres. Graphite seems to give the best agreement, and the results using graphite are presented here.