Ultrasound propagation velocity and acoustic attenuation on agarose phantoms´ in three different manufacture techniques

Ultrasonic phantoms are probe bodies used to mimic the ultrasound properties of biologic tissues. Agarose phantoms are the most widely used of the soft tissue mimics. The IEC 60601-2-37 (2007) describes a recipe of soft tissue mimic material, but some details on its manufacture process are not well defined (for example the stirring technic). In this study agarose-based tissue phantoms based on IEC 60601-2-37 (2007) were made using three different manufacture methods (manual, mechanical or magnetic stirring). The acoustic properties (ultrasound propagation velocity and attenuation coefficient) of the phantoms were determined with their respective uncertainty. Visual differences can be observed between the phantoms for the three different manufacture technics. Phantoms´ ultrasound propagation velocity values were in accordance with IEC 60601-2-37 (2007) and compatible with soft biological tissue. Phantoms´ acoustic attenuation differs with the different stirring techniques. Acoustic attenuation values were compatible with soft biological tissue, but higher than normative TMM (this was expected as granulation of Al₂O₃, used as a backscatter, was higher than in the standard). This study promotes advances in ultrasonic phantoms manufacture.