Ultrasonic properties of silicone breast implants

Ultrasound is useful in evaluating the integrity of silicone breast implants, but is highly operator dependent. A system for computer assisted image interpretation is being developed to reduce operator dependability. Feasibility was examined by measuring the ultrasonic properties of breast implants in vitro. Silicone gel from 17 explanted devices (11 intact and 6 ruptured) were placed in sealed acoustic test chambers and 60 RF A-lines were acquired from each. The mean speed of sound was 1073 m/s±53.76 m/s in intact implants and 1120 m/s±32.34 m/s in ruptured ones (p<0.05). The difference in attenuation between intact and ruptured devices was not statistically significant. The mean integrated backscatter was -68.7 dB±8.98 dB in intact prostheses and -62.8 dB±7.46 dB in ruptured implants. This result shows statistical significance on a 10% level. Changes in speed of sound and integrated backscatter of silicone breast implants have been demonstrated in vitro. While more implants need to be evaluated, the results do indicate the potential for quantitative assessment of the integrity of silicone breast implants performed in vivo