Development Of Ultrasound Phantoms With Controlled Acoustic Properties For Percutaneous Procedures
Ultrasound phantoms with tissue-mimicking acoustic properties play an important role in training and practice for junior clinicians. This study presents a novel tissue-mimicking material that has controllable acoustic properties. It is also realistic under ultrasound imaging and has the potential to be used as training phantoms for clinicians. The tissue-mimicking material comprises of three components: Gel-Wax from Mindsets (UK) Ltd, Paraffin Wax from Alec Tiranti Ltd and Solid Glass Spheres AGC3 0-63microns from Boud Minerals Ltd. It was found that an increase in concentration of paraffin wax, ceteris paribus, could be used to increase two acoustic properties - speed of sound (SOS) and attenuation. It was found that both SOS and attenuation were independent of the concentration of solid glass spheres. However, the amount of solid glass spheres present was found to alter the amount of ultrasound scatter in the phantoms. The ideal combination of these three components to mimic tissue is: 0.5% Solid Glass Spheres + 2% Paraffin Wax + 97.5% Gel-Wax. The values of SOS and attenuation for this combination are: 1420.1±1.6 ms^(-1) and 0.67 ± 0.10 dB.〖MHz〗^(-1).〖cm〗^(-1) respectively. This is in good agreement with the values of SOS and attenuation for soft tissue which is 1561±51 ms^(-1) and 0.54 ± 0.37 dB.〖MHz〗^(-1).〖cm〗^(-1) respectively. Hence, this combination was used to mimic tissue as a background for an ultrasound training phantom with embedded ‘nerve’ and ‘blood vessel’ implants. This training phantom was even found to be more realistic than the state of the art – Blue Phantom™ – under ultrasound imaging. The limitations of this study and material are discussed.