Table 1.
Comparison of typical acoustic impedance values for common biological and biomedical materials.
Figure 1.
PDMS and X-Si aerogel implants prior to implantation in Sprague-Dawley rat.
Optical image of Sylgard 184 PDMS and X-Si aerogel samples prior to insertion in Sprague-Dawley rat for ultrasonic imaging.
Figure 2.
Subcutaneous and sub muscular implant insertion in Sprague-Dawley rat.
Optical images of (a) X-Si aerogel and Sylgard 184 implants being positioned in the abdominal region of a female Sprague-Dawley rat subcutaneously and sub-muscularly. (b) Abdominal section of rat sealed, arrows indicating left and right abdominal positions of four implants. (c) Ultrasound probe positioning during scanning and acquisition of images.
Figure 3.
Pigmented and clear X-Si aerogel implants inserted subcutaneously in a human cadaver.
Pigmented and clear X-Si aerogel implants positioned subcutaneously on the right cheek of human cadaver near and immediately under the bucal nerve region, before repositioning the skin flap.
Figure 4.
Ultrasonic images of subcutaneous and sub muscular implants in Sprague-Dawley rat at 13 MHz.
Ultrasound images of Sylgard 184 and X-Si aerogel acquired from (a) subcutaneous and (b) submuscular abdominal implantation sites. Strong attenuation by X-Si implants has lead to significant posterior shadowing (indicated by arrow) while minimum attenuation by PDMS has created image aberrations (indicated by arrow) referred to as reverberations. Images reflect accurately the size and shape of the implants at both locations.
Figure 5.
Ultrasonic imaging of subcutaneous X-Si aerogel implants in human cadaver at 13 MHz.
(a) Ultrasonic images of pigmented and clear X-Si aerogel implants positioned immediately under the skin, in the parotid region. Some posterior shadowing is observed. The structure of the pigmented (red) and clear aerogels were indistinguishable at the imaged frequency. (b) Parallel and (c) perpendicular orientations of clearX-Si aerogelwith respect to the facial nerve, as indicated by the arrows.
Table 2.
Summary of the ultrasonic response of implants imaged under various conditions.